[PATCH] ipw2100: Fix a gcc compile warning
[linux-2.6/verdex.git] / net / sunrpc / sched.c
blob7415406aa1ae510639e24bc103ea42d3a862db03
1 /*
2 * linux/net/sunrpc/sched.c
4 * Scheduling for synchronous and asynchronous RPC requests.
6 * Copyright (C) 1996 Olaf Kirch, <okir@monad.swb.de>
7 *
8 * TCP NFS related read + write fixes
9 * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
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>
25 #ifdef RPC_DEBUG
26 #define RPCDBG_FACILITY RPCDBG_SCHED
27 #define RPC_TASK_MAGIC_ID 0xf00baa
28 static int rpc_task_id;
29 #endif
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 static 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
77 * rpc_run_timer().
79 static inline void
80 __rpc_disable_timer(struct rpc_task *task)
82 dprintk("RPC: %4d disabling timer\n", task->tk_pid);
83 task->tk_timeout_fn = NULL;
84 task->tk_timeout = 0;
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);
102 callback(task);
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.
112 static inline void
113 __rpc_add_timer(struct rpc_task *task, rpc_action timer)
115 if (!task->tk_timeout)
116 return;
118 dprintk("RPC: %4d setting alarm for %lu ms\n",
119 task->tk_pid, task->tk_timeout * 1000 / HZ);
121 if (timer)
122 task->tk_timeout_fn = timer;
123 else
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.
133 static void
134 rpc_delete_timer(struct rpc_task *task)
136 if (RPC_IS_QUEUED(task))
137 return;
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)
149 struct list_head *q;
150 struct rpc_task *t;
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);
159 return;
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]);
181 else
182 list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
183 task->u.tk_wait.rpc_waitq = queue;
184 rpc_set_queued(task);
186 dprintk("RPC: %4d added to queue %p \"%s\"\n",
187 task->tk_pid, queue, rpc_qname(queue));
191 * Remove request from a priority queue.
193 static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
195 struct rpc_task *t;
197 if (!list_empty(&task->u.tk_wait.links)) {
198 t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list);
199 list_move(&t->u.tk_wait.list, &task->u.tk_wait.list);
200 list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links);
202 list_del(&task->u.tk_wait.list);
206 * Remove request from queue.
207 * Note: must be called with spin lock held.
209 static void __rpc_remove_wait_queue(struct rpc_task *task)
211 struct rpc_wait_queue *queue;
212 queue = task->u.tk_wait.rpc_waitq;
214 if (RPC_IS_PRIORITY(queue))
215 __rpc_remove_wait_queue_priority(task);
216 else
217 list_del(&task->u.tk_wait.list);
218 dprintk("RPC: %4d removed from queue %p \"%s\"\n",
219 task->tk_pid, queue, rpc_qname(queue));
222 static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
224 queue->priority = priority;
225 queue->count = 1 << (priority * 2);
228 static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie)
230 queue->cookie = cookie;
231 queue->nr = RPC_BATCH_COUNT;
234 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
236 rpc_set_waitqueue_priority(queue, queue->maxpriority);
237 rpc_set_waitqueue_cookie(queue, 0);
240 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio)
242 int i;
244 spin_lock_init(&queue->lock);
245 for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
246 INIT_LIST_HEAD(&queue->tasks[i]);
247 queue->maxpriority = maxprio;
248 rpc_reset_waitqueue_priority(queue);
249 #ifdef RPC_DEBUG
250 queue->name = qname;
251 #endif
254 void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
256 __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH);
259 void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
261 __rpc_init_priority_wait_queue(queue, qname, 0);
263 EXPORT_SYMBOL(rpc_init_wait_queue);
265 static int rpc_wait_bit_interruptible(void *word)
267 if (signal_pending(current))
268 return -ERESTARTSYS;
269 schedule();
270 return 0;
274 * Mark an RPC call as having completed by clearing the 'active' bit
276 static inline void rpc_mark_complete_task(struct rpc_task *task)
278 rpc_clear_active(task);
279 wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE);
283 * Allow callers to wait for completion of an RPC call
285 int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *))
287 if (action == NULL)
288 action = rpc_wait_bit_interruptible;
289 return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE,
290 action, TASK_INTERRUPTIBLE);
292 EXPORT_SYMBOL(__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 int do_ret;
304 BUG_ON(task->tk_timeout_fn);
305 do_ret = rpc_test_and_set_running(task);
306 rpc_clear_queued(task);
307 if (do_ret)
308 return;
309 if (RPC_IS_ASYNC(task)) {
310 int status;
312 INIT_WORK(&task->u.tk_work, rpc_async_schedule, (void *)task);
313 status = queue_work(task->tk_workqueue, &task->u.tk_work);
314 if (status < 0) {
315 printk(KERN_WARNING "RPC: failed to add task to queue: error: %d!\n", status);
316 task->tk_status = status;
317 return;
319 } else
320 wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED);
324 * Place a newly initialized task on the workqueue.
326 static inline void
327 rpc_schedule_run(struct rpc_task *task)
329 rpc_set_active(task);
330 rpc_make_runnable(task);
334 * Prepare for sleeping on a wait queue.
335 * By always appending tasks to the list we ensure FIFO behavior.
336 * NB: An RPC task will only receive interrupt-driven events as long
337 * as it's on a wait queue.
339 static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
340 rpc_action action, rpc_action timer)
342 dprintk("RPC: %4d sleep_on(queue \"%s\" time %ld)\n", task->tk_pid,
343 rpc_qname(q), jiffies);
345 if (!RPC_IS_ASYNC(task) && !RPC_IS_ACTIVATED(task)) {
346 printk(KERN_ERR "RPC: Inactive synchronous task put to sleep!\n");
347 return;
350 /* Mark the task as being activated if so needed */
351 rpc_set_active(task);
353 __rpc_add_wait_queue(q, task);
355 BUG_ON(task->tk_callback != NULL);
356 task->tk_callback = action;
357 __rpc_add_timer(task, timer);
360 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
361 rpc_action action, rpc_action timer)
364 * Protect the queue operations.
366 spin_lock_bh(&q->lock);
367 __rpc_sleep_on(q, task, action, timer);
368 spin_unlock_bh(&q->lock);
372 * __rpc_do_wake_up_task - wake up a single rpc_task
373 * @task: task to be woken up
375 * Caller must hold queue->lock, and have cleared the task queued flag.
377 static void __rpc_do_wake_up_task(struct rpc_task *task)
379 dprintk("RPC: %4d __rpc_wake_up_task (now %ld)\n", task->tk_pid, jiffies);
381 #ifdef RPC_DEBUG
382 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
383 #endif
384 /* Has the task been executed yet? If not, we cannot wake it up! */
385 if (!RPC_IS_ACTIVATED(task)) {
386 printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task);
387 return;
390 __rpc_disable_timer(task);
391 __rpc_remove_wait_queue(task);
393 rpc_make_runnable(task);
395 dprintk("RPC: __rpc_wake_up_task done\n");
399 * Wake up the specified task
401 static void __rpc_wake_up_task(struct rpc_task *task)
403 if (rpc_start_wakeup(task)) {
404 if (RPC_IS_QUEUED(task))
405 __rpc_do_wake_up_task(task);
406 rpc_finish_wakeup(task);
411 * Default timeout handler if none specified by user
413 static void
414 __rpc_default_timer(struct rpc_task *task)
416 dprintk("RPC: %d timeout (default timer)\n", task->tk_pid);
417 task->tk_status = -ETIMEDOUT;
418 rpc_wake_up_task(task);
422 * Wake up the specified task
424 void rpc_wake_up_task(struct rpc_task *task)
426 if (rpc_start_wakeup(task)) {
427 if (RPC_IS_QUEUED(task)) {
428 struct rpc_wait_queue *queue = task->u.tk_wait.rpc_waitq;
430 spin_lock_bh(&queue->lock);
431 __rpc_do_wake_up_task(task);
432 spin_unlock_bh(&queue->lock);
434 rpc_finish_wakeup(task);
439 * Wake up the next task on a priority queue.
441 static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue)
443 struct list_head *q;
444 struct rpc_task *task;
447 * Service a batch of tasks from a single cookie.
449 q = &queue->tasks[queue->priority];
450 if (!list_empty(q)) {
451 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
452 if (queue->cookie == task->tk_cookie) {
453 if (--queue->nr)
454 goto out;
455 list_move_tail(&task->u.tk_wait.list, q);
458 * Check if we need to switch queues.
460 if (--queue->count)
461 goto new_cookie;
465 * Service the next queue.
467 do {
468 if (q == &queue->tasks[0])
469 q = &queue->tasks[queue->maxpriority];
470 else
471 q = q - 1;
472 if (!list_empty(q)) {
473 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
474 goto new_queue;
476 } while (q != &queue->tasks[queue->priority]);
478 rpc_reset_waitqueue_priority(queue);
479 return NULL;
481 new_queue:
482 rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
483 new_cookie:
484 rpc_set_waitqueue_cookie(queue, task->tk_cookie);
485 out:
486 __rpc_wake_up_task(task);
487 return task;
491 * Wake up the next task on the wait queue.
493 struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)
495 struct rpc_task *task = NULL;
497 dprintk("RPC: wake_up_next(%p \"%s\")\n", queue, rpc_qname(queue));
498 spin_lock_bh(&queue->lock);
499 if (RPC_IS_PRIORITY(queue))
500 task = __rpc_wake_up_next_priority(queue);
501 else {
502 task_for_first(task, &queue->tasks[0])
503 __rpc_wake_up_task(task);
505 spin_unlock_bh(&queue->lock);
507 return task;
511 * rpc_wake_up - wake up all rpc_tasks
512 * @queue: rpc_wait_queue on which the tasks are sleeping
514 * Grabs queue->lock
516 void rpc_wake_up(struct rpc_wait_queue *queue)
518 struct rpc_task *task;
520 struct list_head *head;
521 spin_lock_bh(&queue->lock);
522 head = &queue->tasks[queue->maxpriority];
523 for (;;) {
524 while (!list_empty(head)) {
525 task = list_entry(head->next, struct rpc_task, u.tk_wait.list);
526 __rpc_wake_up_task(task);
528 if (head == &queue->tasks[0])
529 break;
530 head--;
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
540 * Grabs queue->lock
542 void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
544 struct list_head *head;
545 struct rpc_task *task;
547 spin_lock_bh(&queue->lock);
548 head = &queue->tasks[queue->maxpriority];
549 for (;;) {
550 while (!list_empty(head)) {
551 task = list_entry(head->next, struct rpc_task, u.tk_wait.list);
552 task->tk_status = status;
553 __rpc_wake_up_task(task);
555 if (head == &queue->tasks[0])
556 break;
557 head--;
559 spin_unlock_bh(&queue->lock);
563 * Run a task at a later time
565 static void __rpc_atrun(struct rpc_task *);
566 void
567 rpc_delay(struct rpc_task *task, unsigned long delay)
569 task->tk_timeout = delay;
570 rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun);
573 static void
574 __rpc_atrun(struct rpc_task *task)
576 task->tk_status = 0;
577 rpc_wake_up_task(task);
581 * Helper to call task->tk_ops->rpc_call_prepare
583 static void rpc_prepare_task(struct rpc_task *task)
585 task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
589 * Helper that calls task->tk_ops->rpc_call_done if it exists
591 void rpc_exit_task(struct rpc_task *task)
593 task->tk_action = NULL;
594 if (task->tk_ops->rpc_call_done != NULL) {
595 task->tk_ops->rpc_call_done(task, task->tk_calldata);
596 if (task->tk_action != NULL) {
597 WARN_ON(RPC_ASSASSINATED(task));
598 /* Always release the RPC slot and buffer memory */
599 xprt_release(task);
603 EXPORT_SYMBOL(rpc_exit_task);
606 * This is the RPC `scheduler' (or rather, the finite state machine).
608 static int __rpc_execute(struct rpc_task *task)
610 int status = 0;
612 dprintk("RPC: %4d rpc_execute flgs %x\n",
613 task->tk_pid, task->tk_flags);
615 BUG_ON(RPC_IS_QUEUED(task));
617 for (;;) {
619 * Garbage collection of pending timers...
621 rpc_delete_timer(task);
624 * Execute any pending callback.
626 if (RPC_DO_CALLBACK(task)) {
627 /* Define a callback save pointer */
628 void (*save_callback)(struct rpc_task *);
631 * If a callback exists, save it, reset it,
632 * call it.
633 * The save is needed to stop from resetting
634 * another callback set within the callback handler
635 * - Dave
637 save_callback=task->tk_callback;
638 task->tk_callback=NULL;
639 lock_kernel();
640 save_callback(task);
641 unlock_kernel();
645 * Perform the next FSM step.
646 * tk_action may be NULL when the task has been killed
647 * by someone else.
649 if (!RPC_IS_QUEUED(task)) {
650 if (task->tk_action == NULL)
651 break;
652 lock_kernel();
653 task->tk_action(task);
654 unlock_kernel();
658 * Lockless check for whether task is sleeping or not.
660 if (!RPC_IS_QUEUED(task))
661 continue;
662 rpc_clear_running(task);
663 if (RPC_IS_ASYNC(task)) {
664 /* Careful! we may have raced... */
665 if (RPC_IS_QUEUED(task))
666 return 0;
667 if (rpc_test_and_set_running(task))
668 return 0;
669 continue;
672 /* sync task: sleep here */
673 dprintk("RPC: %4d sync task going to sleep\n", task->tk_pid);
674 /* Note: Caller should be using rpc_clnt_sigmask() */
675 status = out_of_line_wait_on_bit(&task->tk_runstate,
676 RPC_TASK_QUEUED, rpc_wait_bit_interruptible,
677 TASK_INTERRUPTIBLE);
678 if (status == -ERESTARTSYS) {
680 * When a sync task receives a signal, it exits with
681 * -ERESTARTSYS. In order to catch any callbacks that
682 * clean up after sleeping on some queue, we don't
683 * break the loop here, but go around once more.
685 dprintk("RPC: %4d got signal\n", task->tk_pid);
686 task->tk_flags |= RPC_TASK_KILLED;
687 rpc_exit(task, -ERESTARTSYS);
688 rpc_wake_up_task(task);
690 rpc_set_running(task);
691 dprintk("RPC: %4d sync task resuming\n", task->tk_pid);
694 dprintk("RPC: %4d, return %d, status %d\n", task->tk_pid, status, task->tk_status);
695 /* Wake up anyone who is waiting for task completion */
696 rpc_mark_complete_task(task);
697 /* Release all resources associated with the task */
698 rpc_release_task(task);
699 return status;
703 * User-visible entry point to the scheduler.
705 * This may be called recursively if e.g. an async NFS task updates
706 * the attributes and finds that dirty pages must be flushed.
707 * NOTE: Upon exit of this function the task is guaranteed to be
708 * released. In particular note that tk_release() will have
709 * been called, so your task memory may have been freed.
712 rpc_execute(struct rpc_task *task)
714 rpc_set_active(task);
715 rpc_set_running(task);
716 return __rpc_execute(task);
719 static void rpc_async_schedule(void *arg)
721 __rpc_execute((struct rpc_task *)arg);
725 * rpc_malloc - allocate an RPC buffer
726 * @task: RPC task that will use this buffer
727 * @size: requested byte size
729 * We try to ensure that some NFS reads and writes can always proceed
730 * by using a mempool when allocating 'small' buffers.
731 * In order to avoid memory starvation triggering more writebacks of
732 * NFS requests, we use GFP_NOFS rather than GFP_KERNEL.
734 void * rpc_malloc(struct rpc_task *task, size_t size)
736 struct rpc_rqst *req = task->tk_rqstp;
737 gfp_t gfp;
739 if (task->tk_flags & RPC_TASK_SWAPPER)
740 gfp = GFP_ATOMIC;
741 else
742 gfp = GFP_NOFS;
744 if (size > RPC_BUFFER_MAXSIZE) {
745 req->rq_buffer = kmalloc(size, gfp);
746 if (req->rq_buffer)
747 req->rq_bufsize = size;
748 } else {
749 req->rq_buffer = mempool_alloc(rpc_buffer_mempool, gfp);
750 if (req->rq_buffer)
751 req->rq_bufsize = RPC_BUFFER_MAXSIZE;
753 return req->rq_buffer;
757 * rpc_free - free buffer allocated via rpc_malloc
758 * @task: RPC task with a buffer to be freed
761 void rpc_free(struct rpc_task *task)
763 struct rpc_rqst *req = task->tk_rqstp;
765 if (req->rq_buffer) {
766 if (req->rq_bufsize == RPC_BUFFER_MAXSIZE)
767 mempool_free(req->rq_buffer, rpc_buffer_mempool);
768 else
769 kfree(req->rq_buffer);
770 req->rq_buffer = NULL;
771 req->rq_bufsize = 0;
776 * Creation and deletion of RPC task structures
778 void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
780 memset(task, 0, sizeof(*task));
781 init_timer(&task->tk_timer);
782 task->tk_timer.data = (unsigned long) task;
783 task->tk_timer.function = (void (*)(unsigned long)) rpc_run_timer;
784 atomic_set(&task->tk_count, 1);
785 task->tk_client = clnt;
786 task->tk_flags = flags;
787 task->tk_ops = tk_ops;
788 if (tk_ops->rpc_call_prepare != NULL)
789 task->tk_action = rpc_prepare_task;
790 task->tk_calldata = calldata;
792 /* Initialize retry counters */
793 task->tk_garb_retry = 2;
794 task->tk_cred_retry = 2;
796 task->tk_priority = RPC_PRIORITY_NORMAL;
797 task->tk_cookie = (unsigned long)current;
799 /* Initialize workqueue for async tasks */
800 task->tk_workqueue = rpciod_workqueue;
802 if (clnt) {
803 atomic_inc(&clnt->cl_users);
804 if (clnt->cl_softrtry)
805 task->tk_flags |= RPC_TASK_SOFT;
806 if (!clnt->cl_intr)
807 task->tk_flags |= RPC_TASK_NOINTR;
810 #ifdef RPC_DEBUG
811 task->tk_magic = RPC_TASK_MAGIC_ID;
812 task->tk_pid = rpc_task_id++;
813 #endif
814 /* Add to global list of all tasks */
815 spin_lock(&rpc_sched_lock);
816 list_add_tail(&task->tk_task, &all_tasks);
817 spin_unlock(&rpc_sched_lock);
819 BUG_ON(task->tk_ops == NULL);
821 dprintk("RPC: %4d new task procpid %d\n", task->tk_pid,
822 current->pid);
825 static struct rpc_task *
826 rpc_alloc_task(void)
828 return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
831 static void rpc_free_task(struct rpc_task *task)
833 dprintk("RPC: %4d freeing task\n", task->tk_pid);
834 mempool_free(task, rpc_task_mempool);
838 * Create a new task for the specified client. We have to
839 * clean up after an allocation failure, as the client may
840 * have specified "oneshot".
842 struct rpc_task *rpc_new_task(struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
844 struct rpc_task *task;
846 task = rpc_alloc_task();
847 if (!task)
848 goto cleanup;
850 rpc_init_task(task, clnt, flags, tk_ops, calldata);
852 dprintk("RPC: %4d allocated task\n", task->tk_pid);
853 task->tk_flags |= RPC_TASK_DYNAMIC;
854 out:
855 return task;
857 cleanup:
858 /* Check whether to release the client */
859 if (clnt) {
860 printk("rpc_new_task: failed, users=%d, oneshot=%d\n",
861 atomic_read(&clnt->cl_users), clnt->cl_oneshot);
862 atomic_inc(&clnt->cl_users); /* pretend we were used ... */
863 rpc_release_client(clnt);
865 goto out;
868 void rpc_release_task(struct rpc_task *task)
870 const struct rpc_call_ops *tk_ops = task->tk_ops;
871 void *calldata = task->tk_calldata;
873 #ifdef RPC_DEBUG
874 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
875 #endif
876 if (!atomic_dec_and_test(&task->tk_count))
877 return;
878 dprintk("RPC: %4d release task\n", task->tk_pid);
880 /* Remove from global task list */
881 spin_lock(&rpc_sched_lock);
882 list_del(&task->tk_task);
883 spin_unlock(&rpc_sched_lock);
885 BUG_ON (RPC_IS_QUEUED(task));
887 /* Synchronously delete any running timer */
888 rpc_delete_timer(task);
890 /* Release resources */
891 if (task->tk_rqstp)
892 xprt_release(task);
893 if (task->tk_msg.rpc_cred)
894 rpcauth_unbindcred(task);
895 if (task->tk_client) {
896 rpc_release_client(task->tk_client);
897 task->tk_client = NULL;
900 #ifdef RPC_DEBUG
901 task->tk_magic = 0;
902 #endif
903 if (task->tk_flags & RPC_TASK_DYNAMIC)
904 rpc_free_task(task);
905 if (tk_ops->rpc_release)
906 tk_ops->rpc_release(calldata);
910 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
911 * @clnt - pointer to RPC client
912 * @flags - RPC flags
913 * @ops - RPC call ops
914 * @data - user call data
916 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
917 const struct rpc_call_ops *ops,
918 void *data)
920 struct rpc_task *task;
921 task = rpc_new_task(clnt, flags, ops, data);
922 if (task == NULL)
923 return ERR_PTR(-ENOMEM);
924 atomic_inc(&task->tk_count);
925 rpc_execute(task);
926 return task;
928 EXPORT_SYMBOL(rpc_run_task);
931 * rpc_find_parent - find the parent of a child task.
932 * @child: child 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])
946 if (task == parent)
947 return parent;
949 return NULL;
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.
971 struct rpc_task *
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);
977 if (!task)
978 goto fail;
979 return task;
981 fail:
982 parent->tk_status = -ENOMEM;
983 return NULL;
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))
1012 continue;
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");
1034 yield();
1038 spin_lock_irqsave(&current->sighand->siglock, flags);
1039 recalc_sigpending();
1040 spin_unlock_irqrestore(&current->sighand->siglock, flags);
1044 * Start up the rpciod process if it's not already running.
1047 rpciod_up(void)
1049 struct workqueue_struct *wq;
1050 int error = 0;
1052 down(&rpciod_sema);
1053 dprintk("rpciod_up: users %d\n", rpciod_users);
1054 rpciod_users++;
1055 if (rpciod_workqueue)
1056 goto out;
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.
1065 error = -ENOMEM;
1066 wq = create_workqueue("rpciod");
1067 if (wq == NULL) {
1068 printk(KERN_WARNING "rpciod_up: create workqueue failed, error=%d\n", error);
1069 rpciod_users--;
1070 goto out;
1072 rpciod_workqueue = wq;
1073 error = 0;
1074 out:
1075 up(&rpciod_sema);
1076 return error;
1079 void
1080 rpciod_down(void)
1082 down(&rpciod_sema);
1083 dprintk("rpciod_down sema %d\n", rpciod_users);
1084 if (rpciod_users) {
1085 if (--rpciod_users)
1086 goto out;
1087 } else
1088 printk(KERN_WARNING "rpciod_down: no users??\n");
1090 if (!rpciod_workqueue) {
1091 dprintk("rpciod_down: Nothing to do!\n");
1092 goto out;
1094 rpciod_killall();
1096 destroy_workqueue(rpciod_workqueue);
1097 rpciod_workqueue = NULL;
1098 out:
1099 up(&rpciod_sema);
1102 #ifdef RPC_DEBUG
1103 void rpc_show_tasks(void)
1105 struct list_head *le;
1106 struct rpc_task *t;
1108 spin_lock(&rpc_sched_lock);
1109 if (list_empty(&all_tasks)) {
1110 spin_unlock(&rpc_sched_lock);
1111 return;
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",
1122 t->tk_pid,
1123 (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
1124 t->tk_flags, t->tk_status,
1125 t->tk_client,
1126 (t->tk_client ? t->tk_client->cl_prog : 0),
1127 t->tk_rqstp, t->tk_timeout,
1128 rpc_waitq,
1129 t->tk_action, t->tk_ops);
1131 spin_unlock(&rpc_sched_lock);
1133 #endif
1135 void
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,
1154 NULL, NULL);
1155 if (!rpc_task_slabp)
1156 goto err_nomem;
1157 rpc_buffer_slabp = kmem_cache_create("rpc_buffers",
1158 RPC_BUFFER_MAXSIZE,
1159 0, SLAB_HWCACHE_ALIGN,
1160 NULL, NULL);
1161 if (!rpc_buffer_slabp)
1162 goto err_nomem;
1163 rpc_task_mempool = mempool_create(RPC_TASK_POOLSIZE,
1164 mempool_alloc_slab,
1165 mempool_free_slab,
1166 rpc_task_slabp);
1167 if (!rpc_task_mempool)
1168 goto err_nomem;
1169 rpc_buffer_mempool = mempool_create(RPC_BUFFER_POOLSIZE,
1170 mempool_alloc_slab,
1171 mempool_free_slab,
1172 rpc_buffer_slabp);
1173 if (!rpc_buffer_mempool)
1174 goto err_nomem;
1175 return 0;
1176 err_nomem:
1177 rpc_destroy_mempool();
1178 return -ENOMEM;