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>
22 #include <linux/sunrpc/clnt.h>
23 #include <linux/sunrpc/xprt.h>
26 #define RPCDBG_FACILITY RPCDBG_SCHED
27 #define RPC_TASK_MAGIC_ID 0xf00baa
28 static int rpc_task_id;
32 * RPC slabs and memory pools
34 #define RPC_BUFFER_MAXSIZE (2048)
35 #define RPC_BUFFER_POOLSIZE (8)
36 #define RPC_TASK_POOLSIZE (8)
37 static kmem_cache_t *rpc_task_slabp __read_mostly;
38 static kmem_cache_t *rpc_buffer_slabp __read_mostly;
39 static mempool_t *rpc_task_mempool __read_mostly;
40 static mempool_t *rpc_buffer_mempool __read_mostly;
42 static void __rpc_default_timer(struct rpc_task *task);
43 static void rpciod_killall(void);
44 static void rpc_async_schedule(void *);
47 * RPC tasks that create another task (e.g. for contacting the portmapper)
48 * will wait on this queue for their child's completion
50 static RPC_WAITQ(childq, "childq");
53 * RPC tasks sit here while waiting for conditions to improve.
55 static RPC_WAITQ(delay_queue, "delayq");
58 * All RPC tasks are linked into this list
60 static LIST_HEAD(all_tasks);
63 * rpciod-related stuff
65 static DECLARE_MUTEX(rpciod_sema);
66 static unsigned int rpciod_users;
67 struct workqueue_struct *rpciod_workqueue;
70 * Spinlock for other critical sections of code.
72 static DEFINE_SPINLOCK(rpc_sched_lock);
75 * Disable the timer for a given RPC task. Should be called with
76 * queue->lock and bh_disabled in order to avoid races within
80 __rpc_disable_timer(struct rpc_task *task)
82 dprintk("RPC: %4d disabling timer\n", task->tk_pid);
83 task->tk_timeout_fn = NULL;
88 * Run a timeout function.
89 * We use the callback in order to allow __rpc_wake_up_task()
90 * and friends to disable the timer synchronously on SMP systems
91 * without calling del_timer_sync(). The latter could cause a
92 * deadlock if called while we're holding spinlocks...
94 static void rpc_run_timer(struct rpc_task *task)
96 void (*callback)(struct rpc_task *);
98 callback = task->tk_timeout_fn;
99 task->tk_timeout_fn = NULL;
100 if (callback && RPC_IS_QUEUED(task)) {
101 dprintk("RPC: %4d running timer\n", task->tk_pid);
104 smp_mb__before_clear_bit();
105 clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
106 smp_mb__after_clear_bit();
110 * Set up a timer for the current task.
113 __rpc_add_timer(struct rpc_task *task, rpc_action timer)
115 if (!task->tk_timeout)
118 dprintk("RPC: %4d setting alarm for %lu ms\n",
119 task->tk_pid, task->tk_timeout * 1000 / HZ);
122 task->tk_timeout_fn = timer;
124 task->tk_timeout_fn = __rpc_default_timer;
125 set_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
126 mod_timer(&task->tk_timer, jiffies + task->tk_timeout);
130 * Delete any timer for the current task. Because we use del_timer_sync(),
131 * this function should never be called while holding queue->lock.
134 rpc_delete_timer(struct rpc_task *task)
136 if (RPC_IS_QUEUED(task))
138 if (test_and_clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate)) {
139 del_singleshot_timer_sync(&task->tk_timer);
140 dprintk("RPC: %4d deleting timer\n", task->tk_pid);
145 * Add new request to a priority queue.
147 static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct rpc_task *task)
152 INIT_LIST_HEAD(&task->u.tk_wait.links);
153 q = &queue->tasks[task->tk_priority];
154 if (unlikely(task->tk_priority > queue->maxpriority))
155 q = &queue->tasks[queue->maxpriority];
156 list_for_each_entry(t, q, u.tk_wait.list) {
157 if (t->tk_cookie == task->tk_cookie) {
158 list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
162 list_add_tail(&task->u.tk_wait.list, q);
166 * Add new request to wait queue.
168 * Swapper tasks always get inserted at the head of the queue.
169 * This should avoid many nasty memory deadlocks and hopefully
170 * improve overall performance.
171 * Everyone else gets appended to the queue to ensure proper FIFO behavior.
173 static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
175 BUG_ON (RPC_IS_QUEUED(task));
177 if (RPC_IS_PRIORITY(queue))
178 __rpc_add_wait_queue_priority(queue, task);
179 else if (RPC_IS_SWAPPER(task))
180 list_add(&task->u.tk_wait.list, &queue->tasks[0]);
182 list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
183 task->u.tk_wait.rpc_waitq = queue;
185 rpc_set_queued(task);
187 dprintk("RPC: %4d added to queue %p \"%s\"\n",
188 task->tk_pid, queue, rpc_qname(queue));
192 * Remove request from a priority queue.
194 static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
198 if (!list_empty(&task->u.tk_wait.links)) {
199 t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list);
200 list_move(&t->u.tk_wait.list, &task->u.tk_wait.list);
201 list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links);
203 list_del(&task->u.tk_wait.list);
207 * Remove request from queue.
208 * Note: must be called with spin lock held.
210 static void __rpc_remove_wait_queue(struct rpc_task *task)
212 struct rpc_wait_queue *queue;
213 queue = task->u.tk_wait.rpc_waitq;
215 if (RPC_IS_PRIORITY(queue))
216 __rpc_remove_wait_queue_priority(task);
218 list_del(&task->u.tk_wait.list);
220 dprintk("RPC: %4d removed from queue %p \"%s\"\n",
221 task->tk_pid, queue, rpc_qname(queue));
224 static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
226 queue->priority = priority;
227 queue->count = 1 << (priority * 2);
230 static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie)
232 queue->cookie = cookie;
233 queue->nr = RPC_BATCH_COUNT;
236 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
238 rpc_set_waitqueue_priority(queue, queue->maxpriority);
239 rpc_set_waitqueue_cookie(queue, 0);
242 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio)
246 spin_lock_init(&queue->lock);
247 for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
248 INIT_LIST_HEAD(&queue->tasks[i]);
249 queue->maxpriority = maxprio;
250 rpc_reset_waitqueue_priority(queue);
256 void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
258 __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH);
261 void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
263 __rpc_init_priority_wait_queue(queue, qname, 0);
265 EXPORT_SYMBOL(rpc_init_wait_queue);
267 static int rpc_wait_bit_interruptible(void *word)
269 if (signal_pending(current))
276 * Mark an RPC call as having completed by clearing the 'active' bit
278 static inline void rpc_mark_complete_task(struct rpc_task *task)
280 rpc_clear_active(task);
281 wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE);
285 * Allow callers to wait for completion of an RPC call
287 int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *))
290 action = rpc_wait_bit_interruptible;
291 return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE,
292 action, TASK_INTERRUPTIBLE);
294 EXPORT_SYMBOL(__rpc_wait_for_completion_task);
297 * Make an RPC task runnable.
299 * Note: If the task is ASYNC, this must be called with
300 * the spinlock held to protect the wait queue operation.
302 static void rpc_make_runnable(struct rpc_task *task)
306 BUG_ON(task->tk_timeout_fn);
307 do_ret = rpc_test_and_set_running(task);
308 rpc_clear_queued(task);
311 if (RPC_IS_ASYNC(task)) {
314 INIT_WORK(&task->u.tk_work, rpc_async_schedule, (void *)task);
315 status = queue_work(task->tk_workqueue, &task->u.tk_work);
317 printk(KERN_WARNING "RPC: failed to add task to queue: error: %d!\n", status);
318 task->tk_status = status;
322 wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED);
326 * Place a newly initialized task on the workqueue.
329 rpc_schedule_run(struct rpc_task *task)
331 rpc_set_active(task);
332 rpc_make_runnable(task);
336 * Prepare for sleeping on a wait queue.
337 * By always appending tasks to the list we ensure FIFO behavior.
338 * NB: An RPC task will only receive interrupt-driven events as long
339 * as it's on a wait queue.
341 static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
342 rpc_action action, rpc_action timer)
344 dprintk("RPC: %4d sleep_on(queue \"%s\" time %ld)\n", task->tk_pid,
345 rpc_qname(q), jiffies);
347 if (!RPC_IS_ASYNC(task) && !RPC_IS_ACTIVATED(task)) {
348 printk(KERN_ERR "RPC: Inactive synchronous task put to sleep!\n");
352 /* Mark the task as being activated if so needed */
353 rpc_set_active(task);
355 __rpc_add_wait_queue(q, task);
357 BUG_ON(task->tk_callback != NULL);
358 task->tk_callback = action;
359 __rpc_add_timer(task, timer);
362 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
363 rpc_action action, rpc_action timer)
366 * Protect the queue operations.
368 spin_lock_bh(&q->lock);
369 __rpc_sleep_on(q, task, action, timer);
370 spin_unlock_bh(&q->lock);
374 * __rpc_do_wake_up_task - wake up a single rpc_task
375 * @task: task to be woken up
377 * Caller must hold queue->lock, and have cleared the task queued flag.
379 static void __rpc_do_wake_up_task(struct rpc_task *task)
381 dprintk("RPC: %4d __rpc_wake_up_task (now %ld)\n", task->tk_pid, jiffies);
384 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
386 /* Has the task been executed yet? If not, we cannot wake it up! */
387 if (!RPC_IS_ACTIVATED(task)) {
388 printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task);
392 __rpc_disable_timer(task);
393 __rpc_remove_wait_queue(task);
395 rpc_make_runnable(task);
397 dprintk("RPC: __rpc_wake_up_task done\n");
401 * Wake up the specified task
403 static void __rpc_wake_up_task(struct rpc_task *task)
405 if (rpc_start_wakeup(task)) {
406 if (RPC_IS_QUEUED(task))
407 __rpc_do_wake_up_task(task);
408 rpc_finish_wakeup(task);
413 * Default timeout handler if none specified by user
416 __rpc_default_timer(struct rpc_task *task)
418 dprintk("RPC: %d timeout (default timer)\n", task->tk_pid);
419 task->tk_status = -ETIMEDOUT;
420 rpc_wake_up_task(task);
424 * Wake up the specified task
426 void rpc_wake_up_task(struct rpc_task *task)
428 if (rpc_start_wakeup(task)) {
429 if (RPC_IS_QUEUED(task)) {
430 struct rpc_wait_queue *queue = task->u.tk_wait.rpc_waitq;
432 spin_lock_bh(&queue->lock);
433 __rpc_do_wake_up_task(task);
434 spin_unlock_bh(&queue->lock);
436 rpc_finish_wakeup(task);
441 * Wake up the next task on a priority queue.
443 static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue)
446 struct rpc_task *task;
449 * Service a batch of tasks from a single cookie.
451 q = &queue->tasks[queue->priority];
452 if (!list_empty(q)) {
453 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
454 if (queue->cookie == task->tk_cookie) {
457 list_move_tail(&task->u.tk_wait.list, q);
460 * Check if we need to switch queues.
467 * Service the next queue.
470 if (q == &queue->tasks[0])
471 q = &queue->tasks[queue->maxpriority];
474 if (!list_empty(q)) {
475 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
478 } while (q != &queue->tasks[queue->priority]);
480 rpc_reset_waitqueue_priority(queue);
484 rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
486 rpc_set_waitqueue_cookie(queue, task->tk_cookie);
488 __rpc_wake_up_task(task);
493 * Wake up the next task on the wait queue.
495 struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)
497 struct rpc_task *task = NULL;
499 dprintk("RPC: wake_up_next(%p \"%s\")\n", queue, rpc_qname(queue));
500 spin_lock_bh(&queue->lock);
501 if (RPC_IS_PRIORITY(queue))
502 task = __rpc_wake_up_next_priority(queue);
504 task_for_first(task, &queue->tasks[0])
505 __rpc_wake_up_task(task);
507 spin_unlock_bh(&queue->lock);
513 * rpc_wake_up - wake up all rpc_tasks
514 * @queue: rpc_wait_queue on which the tasks are sleeping
518 void rpc_wake_up(struct rpc_wait_queue *queue)
520 struct rpc_task *task, *next;
521 struct list_head *head;
523 spin_lock_bh(&queue->lock);
524 head = &queue->tasks[queue->maxpriority];
526 list_for_each_entry_safe(task, next, head, u.tk_wait.list)
527 __rpc_wake_up_task(task);
528 if (head == &queue->tasks[0])
532 spin_unlock_bh(&queue->lock);
536 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
537 * @queue: rpc_wait_queue on which the tasks are sleeping
538 * @status: status value to set
542 void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
544 struct rpc_task *task, *next;
545 struct list_head *head;
547 spin_lock_bh(&queue->lock);
548 head = &queue->tasks[queue->maxpriority];
550 list_for_each_entry_safe(task, next, head, u.tk_wait.list) {
551 task->tk_status = status;
552 __rpc_wake_up_task(task);
554 if (head == &queue->tasks[0])
558 spin_unlock_bh(&queue->lock);
562 * Run a task at a later time
564 static void __rpc_atrun(struct rpc_task *);
566 rpc_delay(struct rpc_task *task, unsigned long delay)
568 task->tk_timeout = delay;
569 rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun);
573 __rpc_atrun(struct rpc_task *task)
576 rpc_wake_up_task(task);
580 * Helper to call task->tk_ops->rpc_call_prepare
582 static void rpc_prepare_task(struct rpc_task *task)
584 task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
588 * Helper that calls task->tk_ops->rpc_call_done if it exists
590 void rpc_exit_task(struct rpc_task *task)
592 task->tk_action = NULL;
593 if (task->tk_ops->rpc_call_done != NULL) {
594 task->tk_ops->rpc_call_done(task, task->tk_calldata);
595 if (task->tk_action != NULL) {
596 WARN_ON(RPC_ASSASSINATED(task));
597 /* Always release the RPC slot and buffer memory */
602 EXPORT_SYMBOL(rpc_exit_task);
605 * This is the RPC `scheduler' (or rather, the finite state machine).
607 static int __rpc_execute(struct rpc_task *task)
611 dprintk("RPC: %4d rpc_execute flgs %x\n",
612 task->tk_pid, task->tk_flags);
614 BUG_ON(RPC_IS_QUEUED(task));
618 * Garbage collection of pending timers...
620 rpc_delete_timer(task);
623 * Execute any pending callback.
625 if (RPC_DO_CALLBACK(task)) {
626 /* Define a callback save pointer */
627 void (*save_callback)(struct rpc_task *);
630 * If a callback exists, save it, reset it,
632 * The save is needed to stop from resetting
633 * another callback set within the callback handler
636 save_callback=task->tk_callback;
637 task->tk_callback=NULL;
644 * Perform the next FSM step.
645 * tk_action may be NULL when the task has been killed
648 if (!RPC_IS_QUEUED(task)) {
649 if (task->tk_action == NULL)
652 task->tk_action(task);
657 * Lockless check for whether task is sleeping or not.
659 if (!RPC_IS_QUEUED(task))
661 rpc_clear_running(task);
662 if (RPC_IS_ASYNC(task)) {
663 /* Careful! we may have raced... */
664 if (RPC_IS_QUEUED(task))
666 if (rpc_test_and_set_running(task))
671 /* sync task: sleep here */
672 dprintk("RPC: %4d sync task going to sleep\n", task->tk_pid);
673 /* Note: Caller should be using rpc_clnt_sigmask() */
674 status = out_of_line_wait_on_bit(&task->tk_runstate,
675 RPC_TASK_QUEUED, rpc_wait_bit_interruptible,
677 if (status == -ERESTARTSYS) {
679 * When a sync task receives a signal, it exits with
680 * -ERESTARTSYS. In order to catch any callbacks that
681 * clean up after sleeping on some queue, we don't
682 * break the loop here, but go around once more.
684 dprintk("RPC: %4d got signal\n", task->tk_pid);
685 task->tk_flags |= RPC_TASK_KILLED;
686 rpc_exit(task, -ERESTARTSYS);
687 rpc_wake_up_task(task);
689 rpc_set_running(task);
690 dprintk("RPC: %4d sync task resuming\n", task->tk_pid);
693 dprintk("RPC: %4d, return %d, status %d\n", task->tk_pid, status, task->tk_status);
694 /* Wake up anyone who is waiting for task completion */
695 rpc_mark_complete_task(task);
696 /* Release all resources associated with the task */
697 rpc_release_task(task);
702 * User-visible entry point to the scheduler.
704 * This may be called recursively if e.g. an async NFS task updates
705 * the attributes and finds that dirty pages must be flushed.
706 * NOTE: Upon exit of this function the task is guaranteed to be
707 * released. In particular note that tk_release() will have
708 * been called, so your task memory may have been freed.
711 rpc_execute(struct rpc_task *task)
713 rpc_set_active(task);
714 rpc_set_running(task);
715 return __rpc_execute(task);
718 static void rpc_async_schedule(void *arg)
720 __rpc_execute((struct rpc_task *)arg);
724 * rpc_malloc - allocate an RPC buffer
725 * @task: RPC task that will use this buffer
726 * @size: requested byte size
728 * We try to ensure that some NFS reads and writes can always proceed
729 * by using a mempool when allocating 'small' buffers.
730 * In order to avoid memory starvation triggering more writebacks of
731 * NFS requests, we use GFP_NOFS rather than GFP_KERNEL.
733 void * rpc_malloc(struct rpc_task *task, size_t size)
735 struct rpc_rqst *req = task->tk_rqstp;
738 if (task->tk_flags & RPC_TASK_SWAPPER)
743 if (size > RPC_BUFFER_MAXSIZE) {
744 req->rq_buffer = kmalloc(size, gfp);
746 req->rq_bufsize = size;
748 req->rq_buffer = mempool_alloc(rpc_buffer_mempool, gfp);
750 req->rq_bufsize = RPC_BUFFER_MAXSIZE;
752 return req->rq_buffer;
756 * rpc_free - free buffer allocated via rpc_malloc
757 * @task: RPC task with a buffer to be freed
760 void rpc_free(struct rpc_task *task)
762 struct rpc_rqst *req = task->tk_rqstp;
764 if (req->rq_buffer) {
765 if (req->rq_bufsize == RPC_BUFFER_MAXSIZE)
766 mempool_free(req->rq_buffer, rpc_buffer_mempool);
768 kfree(req->rq_buffer);
769 req->rq_buffer = NULL;
775 * Creation and deletion of RPC task structures
777 void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
779 memset(task, 0, sizeof(*task));
780 init_timer(&task->tk_timer);
781 task->tk_timer.data = (unsigned long) task;
782 task->tk_timer.function = (void (*)(unsigned long)) rpc_run_timer;
783 atomic_set(&task->tk_count, 1);
784 task->tk_client = clnt;
785 task->tk_flags = flags;
786 task->tk_ops = tk_ops;
787 if (tk_ops->rpc_call_prepare != NULL)
788 task->tk_action = rpc_prepare_task;
789 task->tk_calldata = calldata;
791 /* Initialize retry counters */
792 task->tk_garb_retry = 2;
793 task->tk_cred_retry = 2;
795 task->tk_priority = RPC_PRIORITY_NORMAL;
796 task->tk_cookie = (unsigned long)current;
798 /* Initialize workqueue for async tasks */
799 task->tk_workqueue = rpciod_workqueue;
802 atomic_inc(&clnt->cl_users);
803 if (clnt->cl_softrtry)
804 task->tk_flags |= RPC_TASK_SOFT;
806 task->tk_flags |= RPC_TASK_NOINTR;
810 task->tk_magic = RPC_TASK_MAGIC_ID;
811 task->tk_pid = rpc_task_id++;
813 /* Add to global list of all tasks */
814 spin_lock(&rpc_sched_lock);
815 list_add_tail(&task->tk_task, &all_tasks);
816 spin_unlock(&rpc_sched_lock);
818 BUG_ON(task->tk_ops == NULL);
820 dprintk("RPC: %4d new task procpid %d\n", task->tk_pid,
824 static struct rpc_task *
827 return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
830 static void rpc_free_task(struct rpc_task *task)
832 dprintk("RPC: %4d freeing task\n", task->tk_pid);
833 mempool_free(task, rpc_task_mempool);
837 * Create a new task for the specified client. We have to
838 * clean up after an allocation failure, as the client may
839 * have specified "oneshot".
841 struct rpc_task *rpc_new_task(struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
843 struct rpc_task *task;
845 task = rpc_alloc_task();
849 rpc_init_task(task, clnt, flags, tk_ops, calldata);
851 dprintk("RPC: %4d allocated task\n", task->tk_pid);
852 task->tk_flags |= RPC_TASK_DYNAMIC;
857 /* Check whether to release the client */
859 printk("rpc_new_task: failed, users=%d, oneshot=%d\n",
860 atomic_read(&clnt->cl_users), clnt->cl_oneshot);
861 atomic_inc(&clnt->cl_users); /* pretend we were used ... */
862 rpc_release_client(clnt);
867 void rpc_release_task(struct rpc_task *task)
869 const struct rpc_call_ops *tk_ops = task->tk_ops;
870 void *calldata = task->tk_calldata;
873 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
875 if (!atomic_dec_and_test(&task->tk_count))
877 dprintk("RPC: %4d release task\n", task->tk_pid);
879 /* Remove from global task list */
880 spin_lock(&rpc_sched_lock);
881 list_del(&task->tk_task);
882 spin_unlock(&rpc_sched_lock);
884 BUG_ON (RPC_IS_QUEUED(task));
886 /* Synchronously delete any running timer */
887 rpc_delete_timer(task);
889 /* Release resources */
892 if (task->tk_msg.rpc_cred)
893 rpcauth_unbindcred(task);
894 if (task->tk_client) {
895 rpc_release_client(task->tk_client);
896 task->tk_client = NULL;
902 if (task->tk_flags & RPC_TASK_DYNAMIC)
904 if (tk_ops->rpc_release)
905 tk_ops->rpc_release(calldata);
909 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
910 * @clnt: pointer to RPC client
913 * @data: user call data
915 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
916 const struct rpc_call_ops *ops,
919 struct rpc_task *task;
920 task = rpc_new_task(clnt, flags, ops, data);
922 return ERR_PTR(-ENOMEM);
923 atomic_inc(&task->tk_count);
927 EXPORT_SYMBOL(rpc_run_task);
930 * rpc_find_parent - find the parent of a child task.
932 * @parent: parent task
934 * Checks that the parent task is still sleeping on the
935 * queue 'childq'. If so returns a pointer to the parent.
936 * Upon failure returns NULL.
938 * Caller must hold childq.lock
940 static inline struct rpc_task *rpc_find_parent(struct rpc_task *child, struct rpc_task *parent)
942 struct rpc_task *task;
943 struct list_head *le;
945 task_for_each(task, le, &childq.tasks[0])
952 static void rpc_child_exit(struct rpc_task *child, void *calldata)
954 struct rpc_task *parent;
956 spin_lock_bh(&childq.lock);
957 if ((parent = rpc_find_parent(child, calldata)) != NULL) {
958 parent->tk_status = child->tk_status;
959 __rpc_wake_up_task(parent);
961 spin_unlock_bh(&childq.lock);
964 static const struct rpc_call_ops rpc_child_ops = {
965 .rpc_call_done = rpc_child_exit,
969 * Note: rpc_new_task releases the client after a failure.
972 rpc_new_child(struct rpc_clnt *clnt, struct rpc_task *parent)
974 struct rpc_task *task;
976 task = rpc_new_task(clnt, RPC_TASK_ASYNC | RPC_TASK_CHILD, &rpc_child_ops, parent);
982 parent->tk_status = -ENOMEM;
986 void rpc_run_child(struct rpc_task *task, struct rpc_task *child, rpc_action func)
988 spin_lock_bh(&childq.lock);
989 /* N.B. Is it possible for the child to have already finished? */
990 __rpc_sleep_on(&childq, task, func, NULL);
991 rpc_schedule_run(child);
992 spin_unlock_bh(&childq.lock);
996 * Kill all tasks for the given client.
997 * XXX: kill their descendants as well?
999 void rpc_killall_tasks(struct rpc_clnt *clnt)
1001 struct rpc_task *rovr;
1002 struct list_head *le;
1004 dprintk("RPC: killing all tasks for client %p\n", clnt);
1007 * Spin lock all_tasks to prevent changes...
1009 spin_lock(&rpc_sched_lock);
1010 alltask_for_each(rovr, le, &all_tasks) {
1011 if (! RPC_IS_ACTIVATED(rovr))
1013 if (!clnt || rovr->tk_client == clnt) {
1014 rovr->tk_flags |= RPC_TASK_KILLED;
1015 rpc_exit(rovr, -EIO);
1016 rpc_wake_up_task(rovr);
1019 spin_unlock(&rpc_sched_lock);
1022 static DECLARE_MUTEX_LOCKED(rpciod_running);
1024 static void rpciod_killall(void)
1026 unsigned long flags;
1028 while (!list_empty(&all_tasks)) {
1029 clear_thread_flag(TIF_SIGPENDING);
1030 rpc_killall_tasks(NULL);
1031 flush_workqueue(rpciod_workqueue);
1032 if (!list_empty(&all_tasks)) {
1033 dprintk("rpciod_killall: waiting for tasks to exit\n");
1038 spin_lock_irqsave(¤t->sighand->siglock, flags);
1039 recalc_sigpending();
1040 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
1044 * Start up the rpciod process if it's not already running.
1049 struct workqueue_struct *wq;
1053 dprintk("rpciod_up: users %d\n", rpciod_users);
1055 if (rpciod_workqueue)
1058 * If there's no pid, we should be the first user.
1060 if (rpciod_users > 1)
1061 printk(KERN_WARNING "rpciod_up: no workqueue, %d users??\n", rpciod_users);
1063 * Create the rpciod thread and wait for it to start.
1066 wq = create_workqueue("rpciod");
1068 printk(KERN_WARNING "rpciod_up: create workqueue failed, error=%d\n", error);
1072 rpciod_workqueue = wq;
1083 dprintk("rpciod_down sema %d\n", rpciod_users);
1088 printk(KERN_WARNING "rpciod_down: no users??\n");
1090 if (!rpciod_workqueue) {
1091 dprintk("rpciod_down: Nothing to do!\n");
1096 destroy_workqueue(rpciod_workqueue);
1097 rpciod_workqueue = NULL;
1103 void rpc_show_tasks(void)
1105 struct list_head *le;
1108 spin_lock(&rpc_sched_lock);
1109 if (list_empty(&all_tasks)) {
1110 spin_unlock(&rpc_sched_lock);
1113 printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1114 "-rpcwait -action- ---ops--\n");
1115 alltask_for_each(t, le, &all_tasks) {
1116 const char *rpc_waitq = "none";
1118 if (RPC_IS_QUEUED(t))
1119 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1121 printk("%05d %04d %04x %06d %8p %6d %8p %08ld %8s %8p %8p\n",
1123 (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
1124 t->tk_flags, t->tk_status,
1126 (t->tk_client ? t->tk_client->cl_prog : 0),
1127 t->tk_rqstp, t->tk_timeout,
1129 t->tk_action, t->tk_ops);
1131 spin_unlock(&rpc_sched_lock);
1136 rpc_destroy_mempool(void)
1138 if (rpc_buffer_mempool)
1139 mempool_destroy(rpc_buffer_mempool);
1140 if (rpc_task_mempool)
1141 mempool_destroy(rpc_task_mempool);
1142 if (rpc_task_slabp && kmem_cache_destroy(rpc_task_slabp))
1143 printk(KERN_INFO "rpc_task: not all structures were freed\n");
1144 if (rpc_buffer_slabp && kmem_cache_destroy(rpc_buffer_slabp))
1145 printk(KERN_INFO "rpc_buffers: not all structures were freed\n");
1149 rpc_init_mempool(void)
1151 rpc_task_slabp = kmem_cache_create("rpc_tasks",
1152 sizeof(struct rpc_task),
1153 0, SLAB_HWCACHE_ALIGN,
1155 if (!rpc_task_slabp)
1157 rpc_buffer_slabp = kmem_cache_create("rpc_buffers",
1159 0, SLAB_HWCACHE_ALIGN,
1161 if (!rpc_buffer_slabp)
1163 rpc_task_mempool = mempool_create(RPC_TASK_POOLSIZE,
1167 if (!rpc_task_mempool)
1169 rpc_buffer_mempool = mempool_create(RPC_BUFFER_POOLSIZE,
1173 if (!rpc_buffer_mempool)
1177 rpc_destroy_mempool();