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 /* starting timestamp */
821 task
->tk_start
= jiffies
;
823 dprintk("RPC: %4d new task procpid %d\n", task
->tk_pid
,
827 static struct rpc_task
*
830 return (struct rpc_task
*)mempool_alloc(rpc_task_mempool
, GFP_NOFS
);
833 static void rpc_free_task(struct rpc_task
*task
)
835 dprintk("RPC: %4d freeing task\n", task
->tk_pid
);
836 mempool_free(task
, rpc_task_mempool
);
840 * Create a new task for the specified client. We have to
841 * clean up after an allocation failure, as the client may
842 * have specified "oneshot".
844 struct rpc_task
*rpc_new_task(struct rpc_clnt
*clnt
, int flags
, const struct rpc_call_ops
*tk_ops
, void *calldata
)
846 struct rpc_task
*task
;
848 task
= rpc_alloc_task();
852 rpc_init_task(task
, clnt
, flags
, tk_ops
, calldata
);
854 dprintk("RPC: %4d allocated task\n", task
->tk_pid
);
855 task
->tk_flags
|= RPC_TASK_DYNAMIC
;
860 /* Check whether to release the client */
862 printk("rpc_new_task: failed, users=%d, oneshot=%d\n",
863 atomic_read(&clnt
->cl_users
), clnt
->cl_oneshot
);
864 atomic_inc(&clnt
->cl_users
); /* pretend we were used ... */
865 rpc_release_client(clnt
);
870 void rpc_release_task(struct rpc_task
*task
)
872 const struct rpc_call_ops
*tk_ops
= task
->tk_ops
;
873 void *calldata
= task
->tk_calldata
;
876 BUG_ON(task
->tk_magic
!= RPC_TASK_MAGIC_ID
);
878 if (!atomic_dec_and_test(&task
->tk_count
))
880 dprintk("RPC: %4d release task\n", task
->tk_pid
);
882 /* Remove from global task list */
883 spin_lock(&rpc_sched_lock
);
884 list_del(&task
->tk_task
);
885 spin_unlock(&rpc_sched_lock
);
887 BUG_ON (RPC_IS_QUEUED(task
));
889 /* Synchronously delete any running timer */
890 rpc_delete_timer(task
);
892 /* Release resources */
895 if (task
->tk_msg
.rpc_cred
)
896 rpcauth_unbindcred(task
);
897 if (task
->tk_client
) {
898 rpc_release_client(task
->tk_client
);
899 task
->tk_client
= NULL
;
905 if (task
->tk_flags
& RPC_TASK_DYNAMIC
)
907 if (tk_ops
->rpc_release
)
908 tk_ops
->rpc_release(calldata
);
912 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
913 * @clnt: pointer to RPC client
916 * @data: user call data
918 struct rpc_task
*rpc_run_task(struct rpc_clnt
*clnt
, int flags
,
919 const struct rpc_call_ops
*ops
,
922 struct rpc_task
*task
;
923 task
= rpc_new_task(clnt
, flags
, ops
, data
);
925 if (ops
->rpc_release
!= NULL
)
926 ops
->rpc_release(data
);
927 return ERR_PTR(-ENOMEM
);
929 atomic_inc(&task
->tk_count
);
933 EXPORT_SYMBOL(rpc_run_task
);
936 * rpc_find_parent - find the parent of a child task.
938 * @parent: parent task
940 * Checks that the parent task is still sleeping on the
941 * queue 'childq'. If so returns a pointer to the parent.
942 * Upon failure returns NULL.
944 * Caller must hold childq.lock
946 static inline struct rpc_task
*rpc_find_parent(struct rpc_task
*child
, struct rpc_task
*parent
)
948 struct rpc_task
*task
;
949 struct list_head
*le
;
951 task_for_each(task
, le
, &childq
.tasks
[0])
958 static void rpc_child_exit(struct rpc_task
*child
, void *calldata
)
960 struct rpc_task
*parent
;
962 spin_lock_bh(&childq
.lock
);
963 if ((parent
= rpc_find_parent(child
, calldata
)) != NULL
) {
964 parent
->tk_status
= child
->tk_status
;
965 __rpc_wake_up_task(parent
);
967 spin_unlock_bh(&childq
.lock
);
970 static const struct rpc_call_ops rpc_child_ops
= {
971 .rpc_call_done
= rpc_child_exit
,
975 * Note: rpc_new_task releases the client after a failure.
978 rpc_new_child(struct rpc_clnt
*clnt
, struct rpc_task
*parent
)
980 struct rpc_task
*task
;
982 task
= rpc_new_task(clnt
, RPC_TASK_ASYNC
| RPC_TASK_CHILD
, &rpc_child_ops
, parent
);
988 parent
->tk_status
= -ENOMEM
;
992 void rpc_run_child(struct rpc_task
*task
, struct rpc_task
*child
, rpc_action func
)
994 spin_lock_bh(&childq
.lock
);
995 /* N.B. Is it possible for the child to have already finished? */
996 __rpc_sleep_on(&childq
, task
, func
, NULL
);
997 rpc_schedule_run(child
);
998 spin_unlock_bh(&childq
.lock
);
1002 * Kill all tasks for the given client.
1003 * XXX: kill their descendants as well?
1005 void rpc_killall_tasks(struct rpc_clnt
*clnt
)
1007 struct rpc_task
*rovr
;
1008 struct list_head
*le
;
1010 dprintk("RPC: killing all tasks for client %p\n", clnt
);
1013 * Spin lock all_tasks to prevent changes...
1015 spin_lock(&rpc_sched_lock
);
1016 alltask_for_each(rovr
, le
, &all_tasks
) {
1017 if (! RPC_IS_ACTIVATED(rovr
))
1019 if (!clnt
|| rovr
->tk_client
== clnt
) {
1020 rovr
->tk_flags
|= RPC_TASK_KILLED
;
1021 rpc_exit(rovr
, -EIO
);
1022 rpc_wake_up_task(rovr
);
1025 spin_unlock(&rpc_sched_lock
);
1028 static DECLARE_MUTEX_LOCKED(rpciod_running
);
1030 static void rpciod_killall(void)
1032 unsigned long flags
;
1034 while (!list_empty(&all_tasks
)) {
1035 clear_thread_flag(TIF_SIGPENDING
);
1036 rpc_killall_tasks(NULL
);
1037 flush_workqueue(rpciod_workqueue
);
1038 if (!list_empty(&all_tasks
)) {
1039 dprintk("rpciod_killall: waiting for tasks to exit\n");
1044 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
1045 recalc_sigpending();
1046 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
1050 * Start up the rpciod process if it's not already running.
1055 struct workqueue_struct
*wq
;
1059 dprintk("rpciod_up: users %d\n", rpciod_users
);
1061 if (rpciod_workqueue
)
1064 * If there's no pid, we should be the first user.
1066 if (rpciod_users
> 1)
1067 printk(KERN_WARNING
"rpciod_up: no workqueue, %d users??\n", rpciod_users
);
1069 * Create the rpciod thread and wait for it to start.
1072 wq
= create_workqueue("rpciod");
1074 printk(KERN_WARNING
"rpciod_up: create workqueue failed, error=%d\n", error
);
1078 rpciod_workqueue
= wq
;
1089 dprintk("rpciod_down sema %d\n", rpciod_users
);
1094 printk(KERN_WARNING
"rpciod_down: no users??\n");
1096 if (!rpciod_workqueue
) {
1097 dprintk("rpciod_down: Nothing to do!\n");
1102 destroy_workqueue(rpciod_workqueue
);
1103 rpciod_workqueue
= NULL
;
1109 void rpc_show_tasks(void)
1111 struct list_head
*le
;
1114 spin_lock(&rpc_sched_lock
);
1115 if (list_empty(&all_tasks
)) {
1116 spin_unlock(&rpc_sched_lock
);
1119 printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1120 "-rpcwait -action- ---ops--\n");
1121 alltask_for_each(t
, le
, &all_tasks
) {
1122 const char *rpc_waitq
= "none";
1124 if (RPC_IS_QUEUED(t
))
1125 rpc_waitq
= rpc_qname(t
->u
.tk_wait
.rpc_waitq
);
1127 printk("%05d %04d %04x %06d %8p %6d %8p %08ld %8s %8p %8p\n",
1129 (t
->tk_msg
.rpc_proc
? t
->tk_msg
.rpc_proc
->p_proc
: -1),
1130 t
->tk_flags
, t
->tk_status
,
1132 (t
->tk_client
? t
->tk_client
->cl_prog
: 0),
1133 t
->tk_rqstp
, t
->tk_timeout
,
1135 t
->tk_action
, t
->tk_ops
);
1137 spin_unlock(&rpc_sched_lock
);
1142 rpc_destroy_mempool(void)
1144 if (rpc_buffer_mempool
)
1145 mempool_destroy(rpc_buffer_mempool
);
1146 if (rpc_task_mempool
)
1147 mempool_destroy(rpc_task_mempool
);
1148 if (rpc_task_slabp
&& kmem_cache_destroy(rpc_task_slabp
))
1149 printk(KERN_INFO
"rpc_task: not all structures were freed\n");
1150 if (rpc_buffer_slabp
&& kmem_cache_destroy(rpc_buffer_slabp
))
1151 printk(KERN_INFO
"rpc_buffers: not all structures were freed\n");
1155 rpc_init_mempool(void)
1157 rpc_task_slabp
= kmem_cache_create("rpc_tasks",
1158 sizeof(struct rpc_task
),
1159 0, SLAB_HWCACHE_ALIGN
,
1161 if (!rpc_task_slabp
)
1163 rpc_buffer_slabp
= kmem_cache_create("rpc_buffers",
1165 0, SLAB_HWCACHE_ALIGN
,
1167 if (!rpc_buffer_slabp
)
1169 rpc_task_mempool
= mempool_create(RPC_TASK_POOLSIZE
,
1173 if (!rpc_task_mempool
)
1175 rpc_buffer_mempool
= mempool_create(RPC_BUFFER_POOLSIZE
,
1179 if (!rpc_buffer_mempool
)
1183 rpc_destroy_mempool();