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/smp_lock.h>
20 #include <linux/spinlock.h>
21 #include <linux/mutex.h>
23 #include <linux/sunrpc/clnt.h>
26 #define RPCDBG_FACILITY RPCDBG_SCHED
27 #define RPC_TASK_MAGIC_ID 0xf00baa
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);
45 * RPC tasks sit here while waiting for conditions to improve.
47 static struct rpc_wait_queue delay_queue;
50 * rpciod-related stuff
52 struct workqueue_struct *rpciod_workqueue;
55 * Disable the timer for a given RPC task. Should be called with
56 * queue->lock and bh_disabled in order to avoid races within
60 __rpc_disable_timer(struct rpc_task *task)
62 dprintk("RPC: %5u disabling timer\n", task->tk_pid);
63 task->tk_timeout_fn = NULL;
68 * Default timeout handler if none specified by user
71 __rpc_default_timer(struct rpc_task *task)
73 dprintk("RPC: %5u timeout (default timer)\n", task->tk_pid);
74 task->tk_status = -ETIMEDOUT;
78 * Set up a timer for the current task.
81 __rpc_add_timer(struct rpc_task *task, rpc_action timer)
83 if (!task->tk_timeout)
86 dprintk("RPC: %5u setting alarm for %lu ms\n",
87 task->tk_pid, task->tk_timeout * 1000 / HZ);
90 task->tk_timeout_fn = timer;
92 task->tk_timeout_fn = __rpc_default_timer;
93 set_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
94 mod_timer(&task->tk_timer, jiffies + task->tk_timeout);
98 * Delete any timer for the current task. Because we use del_timer_sync(),
99 * this function should never be called while holding queue->lock.
102 rpc_delete_timer(struct rpc_task *task)
104 if (RPC_IS_QUEUED(task))
106 if (test_and_clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate)) {
107 del_singleshot_timer_sync(&task->tk_timer);
108 dprintk("RPC: %5u deleting timer\n", task->tk_pid);
113 * Add new request to a priority queue.
115 static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct rpc_task *task)
120 INIT_LIST_HEAD(&task->u.tk_wait.links);
121 q = &queue->tasks[task->tk_priority];
122 if (unlikely(task->tk_priority > queue->maxpriority))
123 q = &queue->tasks[queue->maxpriority];
124 list_for_each_entry(t, q, u.tk_wait.list) {
125 if (t->tk_owner == task->tk_owner) {
126 list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
130 list_add_tail(&task->u.tk_wait.list, q);
134 * Add new request to wait queue.
136 * Swapper tasks always get inserted at the head of the queue.
137 * This should avoid many nasty memory deadlocks and hopefully
138 * improve overall performance.
139 * Everyone else gets appended to the queue to ensure proper FIFO behavior.
141 static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
143 BUG_ON (RPC_IS_QUEUED(task));
145 if (RPC_IS_PRIORITY(queue))
146 __rpc_add_wait_queue_priority(queue, task);
147 else if (RPC_IS_SWAPPER(task))
148 list_add(&task->u.tk_wait.list, &queue->tasks[0]);
150 list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
151 task->tk_waitqueue = queue;
153 rpc_set_queued(task);
155 dprintk("RPC: %5u added to queue %p \"%s\"\n",
156 task->tk_pid, queue, rpc_qname(queue));
160 * Remove request from a priority queue.
162 static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
166 if (!list_empty(&task->u.tk_wait.links)) {
167 t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list);
168 list_move(&t->u.tk_wait.list, &task->u.tk_wait.list);
169 list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links);
171 list_del(&task->u.tk_wait.list);
175 * Remove request from queue.
176 * Note: must be called with spin lock held.
178 static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
180 if (RPC_IS_PRIORITY(queue))
181 __rpc_remove_wait_queue_priority(task);
183 list_del(&task->u.tk_wait.list);
185 dprintk("RPC: %5u removed from queue %p \"%s\"\n",
186 task->tk_pid, queue, rpc_qname(queue));
189 static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
191 queue->priority = priority;
192 queue->count = 1 << (priority * 2);
195 static inline void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)
198 queue->nr = RPC_BATCH_COUNT;
201 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
203 rpc_set_waitqueue_priority(queue, queue->maxpriority);
204 rpc_set_waitqueue_owner(queue, 0);
207 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues)
211 spin_lock_init(&queue->lock);
212 for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
213 INIT_LIST_HEAD(&queue->tasks[i]);
214 queue->maxpriority = nr_queues - 1;
215 rpc_reset_waitqueue_priority(queue);
221 void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
223 __rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY);
226 void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
228 __rpc_init_priority_wait_queue(queue, qname, 1);
230 EXPORT_SYMBOL_GPL(rpc_init_wait_queue);
232 static int rpc_wait_bit_killable(void *word)
234 if (fatal_signal_pending(current))
241 static void rpc_task_set_debuginfo(struct rpc_task *task)
243 static atomic_t rpc_pid;
245 task->tk_magic = RPC_TASK_MAGIC_ID;
246 task->tk_pid = atomic_inc_return(&rpc_pid);
249 static inline void rpc_task_set_debuginfo(struct rpc_task *task)
254 static void rpc_set_active(struct rpc_task *task)
256 struct rpc_clnt *clnt;
257 if (test_and_set_bit(RPC_TASK_ACTIVE, &task->tk_runstate) != 0)
259 rpc_task_set_debuginfo(task);
260 /* Add to global list of all tasks */
261 clnt = task->tk_client;
263 spin_lock(&clnt->cl_lock);
264 list_add_tail(&task->tk_task, &clnt->cl_tasks);
265 spin_unlock(&clnt->cl_lock);
270 * Mark an RPC call as having completed by clearing the 'active' bit
272 static void rpc_mark_complete_task(struct rpc_task *task)
274 smp_mb__before_clear_bit();
275 clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate);
276 smp_mb__after_clear_bit();
277 wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE);
281 * Allow callers to wait for completion of an RPC call
283 int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *))
286 action = rpc_wait_bit_killable;
287 return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE,
288 action, TASK_KILLABLE);
290 EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task);
293 * Make an RPC task runnable.
295 * Note: If the task is ASYNC, this must be called with
296 * the spinlock held to protect the wait queue operation.
298 static void rpc_make_runnable(struct rpc_task *task)
300 BUG_ON(task->tk_timeout_fn);
301 rpc_clear_queued(task);
302 if (rpc_test_and_set_running(task))
304 /* We might have raced */
305 if (RPC_IS_QUEUED(task)) {
306 rpc_clear_running(task);
309 if (RPC_IS_ASYNC(task)) {
312 INIT_WORK(&task->u.tk_work, rpc_async_schedule);
313 status = queue_work(rpciod_workqueue, &task->u.tk_work);
315 printk(KERN_WARNING "RPC: failed to add task to queue: error: %d!\n", status);
316 task->tk_status = status;
320 wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED);
324 * Prepare for sleeping on a wait queue.
325 * By always appending tasks to the list we ensure FIFO behavior.
326 * NB: An RPC task will only receive interrupt-driven events as long
327 * as it's on a wait queue.
329 static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
330 rpc_action action, rpc_action timer)
332 dprintk("RPC: %5u sleep_on(queue \"%s\" time %lu)\n",
333 task->tk_pid, rpc_qname(q), jiffies);
335 if (!RPC_IS_ASYNC(task) && !RPC_IS_ACTIVATED(task)) {
336 printk(KERN_ERR "RPC: Inactive synchronous task put to sleep!\n");
340 __rpc_add_wait_queue(q, task);
342 BUG_ON(task->tk_callback != NULL);
343 task->tk_callback = action;
344 __rpc_add_timer(task, timer);
347 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
348 rpc_action action, rpc_action timer)
350 /* Mark the task as being activated if so needed */
351 rpc_set_active(task);
354 * Protect the queue operations.
356 spin_lock_bh(&q->lock);
357 __rpc_sleep_on(q, task, action, timer);
358 spin_unlock_bh(&q->lock);
360 EXPORT_SYMBOL_GPL(rpc_sleep_on);
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);
375 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
377 /* Has the task been executed yet? If not, we cannot wake it up! */
378 if (!RPC_IS_ACTIVATED(task)) {
379 printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task);
383 __rpc_disable_timer(task);
384 __rpc_remove_wait_queue(queue, task);
386 rpc_make_runnable(task);
388 dprintk("RPC: __rpc_wake_up_task done\n");
392 * Wake up a queued task while the queue lock is being held
394 static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct rpc_task *task)
396 if (!RPC_IS_QUEUED(task) || task->tk_waitqueue != queue)
398 if (rpc_start_wakeup(task)) {
399 __rpc_do_wake_up_task(queue, task);
400 rpc_finish_wakeup(task);
405 * Wake up a task on a specific queue
407 void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task)
410 spin_lock(&queue->lock);
411 rpc_wake_up_task_queue_locked(queue, task);
412 spin_unlock(&queue->lock);
413 rcu_read_unlock_bh();
415 EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task);
418 * Wake up the specified task
420 static void rpc_wake_up_task(struct rpc_task *task)
422 rpc_wake_up_queued_task(task->tk_waitqueue, task);
426 * Wake up the next task on a priority queue.
428 static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue)
431 struct rpc_task *task;
434 * Service a batch of tasks from a single owner.
436 q = &queue->tasks[queue->priority];
437 if (!list_empty(q)) {
438 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
439 if (queue->owner == task->tk_owner) {
442 list_move_tail(&task->u.tk_wait.list, q);
445 * Check if we need to switch queues.
452 * Service the next queue.
455 if (q == &queue->tasks[0])
456 q = &queue->tasks[queue->maxpriority];
459 if (!list_empty(q)) {
460 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
463 } while (q != &queue->tasks[queue->priority]);
465 rpc_reset_waitqueue_priority(queue);
469 rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
471 rpc_set_waitqueue_owner(queue, task->tk_owner);
473 rpc_wake_up_task_queue_locked(queue, task);
478 * Wake up the next task on the wait queue.
480 struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)
482 struct rpc_task *task = NULL;
484 dprintk("RPC: wake_up_next(%p \"%s\")\n",
485 queue, rpc_qname(queue));
487 spin_lock(&queue->lock);
488 if (RPC_IS_PRIORITY(queue))
489 task = __rpc_wake_up_next_priority(queue);
491 task_for_first(task, &queue->tasks[0])
492 rpc_wake_up_task_queue_locked(queue, task);
494 spin_unlock(&queue->lock);
495 rcu_read_unlock_bh();
499 EXPORT_SYMBOL_GPL(rpc_wake_up_next);
502 * rpc_wake_up - wake up all rpc_tasks
503 * @queue: rpc_wait_queue on which the tasks are sleeping
507 void rpc_wake_up(struct rpc_wait_queue *queue)
509 struct rpc_task *task, *next;
510 struct list_head *head;
513 spin_lock(&queue->lock);
514 head = &queue->tasks[queue->maxpriority];
516 list_for_each_entry_safe(task, next, head, u.tk_wait.list)
517 rpc_wake_up_task_queue_locked(queue, task);
518 if (head == &queue->tasks[0])
522 spin_unlock(&queue->lock);
523 rcu_read_unlock_bh();
525 EXPORT_SYMBOL_GPL(rpc_wake_up);
528 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
529 * @queue: rpc_wait_queue on which the tasks are sleeping
530 * @status: status value to set
534 void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
536 struct rpc_task *task, *next;
537 struct list_head *head;
540 spin_lock(&queue->lock);
541 head = &queue->tasks[queue->maxpriority];
543 list_for_each_entry_safe(task, next, head, u.tk_wait.list) {
544 task->tk_status = status;
545 rpc_wake_up_task_queue_locked(queue, task);
547 if (head == &queue->tasks[0])
551 spin_unlock(&queue->lock);
552 rcu_read_unlock_bh();
554 EXPORT_SYMBOL_GPL(rpc_wake_up_status);
557 * Run a timeout function.
559 static void rpc_run_timer(unsigned long ptr)
561 struct rpc_task *task = (struct rpc_task *)ptr;
562 void (*callback)(struct rpc_task *);
564 if (RPC_IS_QUEUED(task)) {
565 struct rpc_wait_queue *queue = task->tk_waitqueue;
566 callback = task->tk_timeout_fn;
568 dprintk("RPC: %5u running timer\n", task->tk_pid);
569 if (callback != NULL)
571 /* Note: we're already in a bh-safe context */
572 spin_lock(&queue->lock);
573 rpc_wake_up_task_queue_locked(queue, task);
574 spin_unlock(&queue->lock);
576 smp_mb__before_clear_bit();
577 clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
578 smp_mb__after_clear_bit();
581 static void __rpc_atrun(struct rpc_task *task)
586 * Run a task at a later time
588 void rpc_delay(struct rpc_task *task, unsigned long delay)
590 task->tk_timeout = delay;
591 rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun);
593 EXPORT_SYMBOL_GPL(rpc_delay);
596 * Helper to call task->tk_ops->rpc_call_prepare
598 static void rpc_prepare_task(struct rpc_task *task)
601 task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
606 * Helper that calls task->tk_ops->rpc_call_done if it exists
608 void rpc_exit_task(struct rpc_task *task)
610 task->tk_action = NULL;
611 if (task->tk_ops->rpc_call_done != NULL) {
613 task->tk_ops->rpc_call_done(task, task->tk_calldata);
615 if (task->tk_action != NULL) {
616 WARN_ON(RPC_ASSASSINATED(task));
617 /* Always release the RPC slot and buffer memory */
622 EXPORT_SYMBOL_GPL(rpc_exit_task);
624 void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata)
626 if (ops->rpc_release != NULL) {
628 ops->rpc_release(calldata);
634 * This is the RPC `scheduler' (or rather, the finite state machine).
636 static void __rpc_execute(struct rpc_task *task)
640 dprintk("RPC: %5u __rpc_execute flags=0x%x\n",
641 task->tk_pid, task->tk_flags);
643 BUG_ON(RPC_IS_QUEUED(task));
647 * Garbage collection of pending timers...
649 rpc_delete_timer(task);
652 * Execute any pending callback.
654 if (RPC_DO_CALLBACK(task)) {
655 /* Define a callback save pointer */
656 void (*save_callback)(struct rpc_task *);
659 * If a callback exists, save it, reset it,
661 * The save is needed to stop from resetting
662 * another callback set within the callback handler
665 save_callback=task->tk_callback;
666 task->tk_callback=NULL;
671 * Perform the next FSM step.
672 * tk_action may be NULL when the task has been killed
675 if (!RPC_IS_QUEUED(task)) {
676 if (task->tk_action == NULL)
678 task->tk_action(task);
682 * Lockless check for whether task is sleeping or not.
684 if (!RPC_IS_QUEUED(task))
686 rpc_clear_running(task);
687 if (RPC_IS_ASYNC(task)) {
688 /* Careful! we may have raced... */
689 if (RPC_IS_QUEUED(task))
691 if (rpc_test_and_set_running(task))
696 /* sync task: sleep here */
697 dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid);
698 status = out_of_line_wait_on_bit(&task->tk_runstate,
699 RPC_TASK_QUEUED, rpc_wait_bit_killable,
701 if (status == -ERESTARTSYS) {
703 * When a sync task receives a signal, it exits with
704 * -ERESTARTSYS. In order to catch any callbacks that
705 * clean up after sleeping on some queue, we don't
706 * break the loop here, but go around once more.
708 dprintk("RPC: %5u got signal\n", task->tk_pid);
709 task->tk_flags |= RPC_TASK_KILLED;
710 rpc_exit(task, -ERESTARTSYS);
711 rpc_wake_up_task(task);
713 rpc_set_running(task);
714 dprintk("RPC: %5u sync task resuming\n", task->tk_pid);
717 dprintk("RPC: %5u return %d, status %d\n", task->tk_pid, status,
719 /* Release all resources associated with the task */
720 rpc_release_task(task);
724 * User-visible entry point to the scheduler.
726 * This may be called recursively if e.g. an async NFS task updates
727 * the attributes and finds that dirty pages must be flushed.
728 * NOTE: Upon exit of this function the task is guaranteed to be
729 * released. In particular note that tk_release() will have
730 * been called, so your task memory may have been freed.
732 void rpc_execute(struct rpc_task *task)
734 rpc_set_active(task);
735 rpc_set_running(task);
739 static void rpc_async_schedule(struct work_struct *work)
741 __rpc_execute(container_of(work, struct rpc_task, u.tk_work));
750 * rpc_malloc - allocate an RPC buffer
751 * @task: RPC task that will use this buffer
752 * @size: requested byte size
754 * To prevent rpciod from hanging, this allocator never sleeps,
755 * returning NULL if the request cannot be serviced immediately.
756 * The caller can arrange to sleep in a way that is safe for rpciod.
758 * Most requests are 'small' (under 2KiB) and can be serviced from a
759 * mempool, ensuring that NFS reads and writes can always proceed,
760 * and that there is good locality of reference for these buffers.
762 * In order to avoid memory starvation triggering more writebacks of
763 * NFS requests, we avoid using GFP_KERNEL.
765 void *rpc_malloc(struct rpc_task *task, size_t size)
767 struct rpc_buffer *buf;
768 gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT;
770 size += sizeof(struct rpc_buffer);
771 if (size <= RPC_BUFFER_MAXSIZE)
772 buf = mempool_alloc(rpc_buffer_mempool, gfp);
774 buf = kmalloc(size, gfp);
780 dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
781 task->tk_pid, size, buf);
784 EXPORT_SYMBOL_GPL(rpc_malloc);
787 * rpc_free - free buffer allocated via rpc_malloc
788 * @buffer: buffer to free
791 void rpc_free(void *buffer)
794 struct rpc_buffer *buf;
799 buf = container_of(buffer, struct rpc_buffer, data);
802 dprintk("RPC: freeing buffer of size %zu at %p\n",
805 if (size <= RPC_BUFFER_MAXSIZE)
806 mempool_free(buf, rpc_buffer_mempool);
810 EXPORT_SYMBOL_GPL(rpc_free);
813 * Creation and deletion of RPC task structures
815 static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data)
817 memset(task, 0, sizeof(*task));
818 setup_timer(&task->tk_timer, rpc_run_timer, (unsigned long)task);
819 atomic_set(&task->tk_count, 1);
820 task->tk_flags = task_setup_data->flags;
821 task->tk_ops = task_setup_data->callback_ops;
822 task->tk_calldata = task_setup_data->callback_data;
823 INIT_LIST_HEAD(&task->tk_task);
825 /* Initialize retry counters */
826 task->tk_garb_retry = 2;
827 task->tk_cred_retry = 2;
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 task->tk_client = task_setup_data->rpc_client;
836 if (task->tk_client != NULL) {
837 kref_get(&task->tk_client->cl_kref);
838 if (task->tk_client->cl_softrtry)
839 task->tk_flags |= RPC_TASK_SOFT;
842 if (task->tk_ops->rpc_call_prepare != NULL)
843 task->tk_action = rpc_prepare_task;
845 if (task_setup_data->rpc_message != NULL) {
846 memcpy(&task->tk_msg, task_setup_data->rpc_message, sizeof(task->tk_msg));
847 /* Bind the user cred */
848 if (task->tk_msg.rpc_cred != NULL)
849 rpcauth_holdcred(task);
851 rpcauth_bindcred(task);
852 if (task->tk_action == NULL)
853 rpc_call_start(task);
856 /* starting timestamp */
857 task->tk_start = jiffies;
859 dprintk("RPC: new task initialized, procpid %u\n",
860 task_pid_nr(current));
863 static struct rpc_task *
866 return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
869 static void rpc_free_task_rcu(struct rcu_head *rcu)
871 struct rpc_task *task = container_of(rcu, struct rpc_task, u.tk_rcu);
872 dprintk("RPC: %5u freeing task\n", task->tk_pid);
873 mempool_free(task, rpc_task_mempool);
877 * Create a new task for the specified client.
879 struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data)
881 struct rpc_task *task = setup_data->task;
882 unsigned short flags = 0;
885 task = rpc_alloc_task();
888 flags = RPC_TASK_DYNAMIC;
891 rpc_init_task(task, setup_data);
893 task->tk_flags |= flags;
894 dprintk("RPC: allocated task %p\n", task);
899 static void rpc_free_task(struct rpc_task *task)
901 const struct rpc_call_ops *tk_ops = task->tk_ops;
902 void *calldata = task->tk_calldata;
904 if (task->tk_flags & RPC_TASK_DYNAMIC)
905 call_rcu_bh(&task->u.tk_rcu, rpc_free_task_rcu);
906 rpc_release_calldata(tk_ops, calldata);
909 static void rpc_async_release(struct work_struct *work)
911 rpc_free_task(container_of(work, struct rpc_task, u.tk_work));
914 void rpc_put_task(struct rpc_task *task)
916 if (!atomic_dec_and_test(&task->tk_count))
918 /* Release resources */
921 if (task->tk_msg.rpc_cred)
922 rpcauth_unbindcred(task);
923 if (task->tk_client) {
924 rpc_release_client(task->tk_client);
925 task->tk_client = NULL;
927 if (task->tk_workqueue != NULL) {
928 INIT_WORK(&task->u.tk_work, rpc_async_release);
929 queue_work(task->tk_workqueue, &task->u.tk_work);
933 EXPORT_SYMBOL_GPL(rpc_put_task);
935 static void rpc_release_task(struct rpc_task *task)
938 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
940 dprintk("RPC: %5u release task\n", task->tk_pid);
942 if (!list_empty(&task->tk_task)) {
943 struct rpc_clnt *clnt = task->tk_client;
944 /* Remove from client task list */
945 spin_lock(&clnt->cl_lock);
946 list_del(&task->tk_task);
947 spin_unlock(&clnt->cl_lock);
949 BUG_ON (RPC_IS_QUEUED(task));
951 /* Synchronously delete any running timer */
952 rpc_delete_timer(task);
957 /* Wake up anyone who is waiting for task completion */
958 rpc_mark_complete_task(task);
964 * Kill all tasks for the given client.
965 * XXX: kill their descendants as well?
967 void rpc_killall_tasks(struct rpc_clnt *clnt)
969 struct rpc_task *rovr;
972 if (list_empty(&clnt->cl_tasks))
974 dprintk("RPC: killing all tasks for client %p\n", clnt);
976 * Spin lock all_tasks to prevent changes...
978 spin_lock(&clnt->cl_lock);
979 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
980 if (! RPC_IS_ACTIVATED(rovr))
982 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
983 rovr->tk_flags |= RPC_TASK_KILLED;
984 rpc_exit(rovr, -EIO);
985 rpc_wake_up_task(rovr);
988 spin_unlock(&clnt->cl_lock);
990 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
994 return try_module_get(THIS_MODULE) ? 0 : -EINVAL;
997 void rpciod_down(void)
999 module_put(THIS_MODULE);
1003 * Start up the rpciod workqueue.
1005 static int rpciod_start(void)
1007 struct workqueue_struct *wq;
1010 * Create the rpciod thread and wait for it to start.
1012 dprintk("RPC: creating workqueue rpciod\n");
1013 wq = create_workqueue("rpciod");
1014 rpciod_workqueue = wq;
1015 return rpciod_workqueue != NULL;
1018 static void rpciod_stop(void)
1020 struct workqueue_struct *wq = NULL;
1022 if (rpciod_workqueue == NULL)
1024 dprintk("RPC: destroying workqueue rpciod\n");
1026 wq = rpciod_workqueue;
1027 rpciod_workqueue = NULL;
1028 destroy_workqueue(wq);
1032 rpc_destroy_mempool(void)
1035 if (rpc_buffer_mempool)
1036 mempool_destroy(rpc_buffer_mempool);
1037 if (rpc_task_mempool)
1038 mempool_destroy(rpc_task_mempool);
1040 kmem_cache_destroy(rpc_task_slabp);
1041 if (rpc_buffer_slabp)
1042 kmem_cache_destroy(rpc_buffer_slabp);
1046 rpc_init_mempool(void)
1048 rpc_task_slabp = kmem_cache_create("rpc_tasks",
1049 sizeof(struct rpc_task),
1050 0, SLAB_HWCACHE_ALIGN,
1052 if (!rpc_task_slabp)
1054 rpc_buffer_slabp = kmem_cache_create("rpc_buffers",
1056 0, SLAB_HWCACHE_ALIGN,
1058 if (!rpc_buffer_slabp)
1060 rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE,
1062 if (!rpc_task_mempool)
1064 rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE,
1066 if (!rpc_buffer_mempool)
1068 if (!rpciod_start())
1071 * The following is not strictly a mempool initialisation,
1072 * but there is no harm in doing it here
1074 rpc_init_wait_queue(&delay_queue, "delayq");
1077 rpc_destroy_mempool();