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>
24 #include <linux/sunrpc/xprt.h>
27 #define RPCDBG_FACILITY RPCDBG_SCHED
28 #define RPC_TASK_MAGIC_ID 0xf00baa
29 static int rpc_task_id
;
33 * RPC slabs and memory pools
35 #define RPC_BUFFER_MAXSIZE (2048)
36 #define RPC_BUFFER_POOLSIZE (8)
37 #define RPC_TASK_POOLSIZE (8)
38 static kmem_cache_t
*rpc_task_slabp __read_mostly
;
39 static kmem_cache_t
*rpc_buffer_slabp __read_mostly
;
40 static mempool_t
*rpc_task_mempool __read_mostly
;
41 static mempool_t
*rpc_buffer_mempool __read_mostly
;
43 static void __rpc_default_timer(struct rpc_task
*task
);
44 static void rpciod_killall(void);
45 static void rpc_async_schedule(void *);
48 * RPC tasks that create another task (e.g. for contacting the portmapper)
49 * will wait on this queue for their child's completion
51 static RPC_WAITQ(childq
, "childq");
54 * RPC tasks sit here while waiting for conditions to improve.
56 static RPC_WAITQ(delay_queue
, "delayq");
59 * All RPC tasks are linked into this list
61 static LIST_HEAD(all_tasks
);
64 * rpciod-related stuff
66 static DEFINE_MUTEX(rpciod_mutex
);
67 static unsigned int rpciod_users
;
68 static struct workqueue_struct
*rpciod_workqueue
;
71 * Spinlock for other critical sections of code.
73 static DEFINE_SPINLOCK(rpc_sched_lock
);
76 * Disable the timer for a given RPC task. Should be called with
77 * queue->lock and bh_disabled in order to avoid races within
81 __rpc_disable_timer(struct rpc_task
*task
)
83 dprintk("RPC: %4d disabling timer\n", task
->tk_pid
);
84 task
->tk_timeout_fn
= NULL
;
89 * Run a timeout function.
90 * We use the callback in order to allow __rpc_wake_up_task()
91 * and friends to disable the timer synchronously on SMP systems
92 * without calling del_timer_sync(). The latter could cause a
93 * deadlock if called while we're holding spinlocks...
95 static void rpc_run_timer(struct rpc_task
*task
)
97 void (*callback
)(struct rpc_task
*);
99 callback
= task
->tk_timeout_fn
;
100 task
->tk_timeout_fn
= NULL
;
101 if (callback
&& RPC_IS_QUEUED(task
)) {
102 dprintk("RPC: %4d running timer\n", task
->tk_pid
);
105 smp_mb__before_clear_bit();
106 clear_bit(RPC_TASK_HAS_TIMER
, &task
->tk_runstate
);
107 smp_mb__after_clear_bit();
111 * Set up a timer for the current task.
114 __rpc_add_timer(struct rpc_task
*task
, rpc_action timer
)
116 if (!task
->tk_timeout
)
119 dprintk("RPC: %4d setting alarm for %lu ms\n",
120 task
->tk_pid
, task
->tk_timeout
* 1000 / HZ
);
123 task
->tk_timeout_fn
= timer
;
125 task
->tk_timeout_fn
= __rpc_default_timer
;
126 set_bit(RPC_TASK_HAS_TIMER
, &task
->tk_runstate
);
127 mod_timer(&task
->tk_timer
, jiffies
+ task
->tk_timeout
);
131 * Delete any timer for the current task. Because we use del_timer_sync(),
132 * this function should never be called while holding queue->lock.
135 rpc_delete_timer(struct rpc_task
*task
)
137 if (RPC_IS_QUEUED(task
))
139 if (test_and_clear_bit(RPC_TASK_HAS_TIMER
, &task
->tk_runstate
)) {
140 del_singleshot_timer_sync(&task
->tk_timer
);
141 dprintk("RPC: %4d deleting timer\n", task
->tk_pid
);
146 * Add new request to a priority queue.
148 static void __rpc_add_wait_queue_priority(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
153 INIT_LIST_HEAD(&task
->u
.tk_wait
.links
);
154 q
= &queue
->tasks
[task
->tk_priority
];
155 if (unlikely(task
->tk_priority
> queue
->maxpriority
))
156 q
= &queue
->tasks
[queue
->maxpriority
];
157 list_for_each_entry(t
, q
, u
.tk_wait
.list
) {
158 if (t
->tk_cookie
== task
->tk_cookie
) {
159 list_add_tail(&task
->u
.tk_wait
.list
, &t
->u
.tk_wait
.links
);
163 list_add_tail(&task
->u
.tk_wait
.list
, q
);
167 * Add new request to wait queue.
169 * Swapper tasks always get inserted at the head of the queue.
170 * This should avoid many nasty memory deadlocks and hopefully
171 * improve overall performance.
172 * Everyone else gets appended to the queue to ensure proper FIFO behavior.
174 static void __rpc_add_wait_queue(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
176 BUG_ON (RPC_IS_QUEUED(task
));
178 if (RPC_IS_PRIORITY(queue
))
179 __rpc_add_wait_queue_priority(queue
, task
);
180 else if (RPC_IS_SWAPPER(task
))
181 list_add(&task
->u
.tk_wait
.list
, &queue
->tasks
[0]);
183 list_add_tail(&task
->u
.tk_wait
.list
, &queue
->tasks
[0]);
184 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
);
219 dprintk("RPC: %4d removed from queue %p \"%s\"\n",
220 task
->tk_pid
, queue
, rpc_qname(queue
));
223 static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue
*queue
, int priority
)
225 queue
->priority
= priority
;
226 queue
->count
= 1 << (priority
* 2);
229 static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue
*queue
, unsigned long cookie
)
231 queue
->cookie
= cookie
;
232 queue
->nr
= RPC_BATCH_COUNT
;
235 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue
*queue
)
237 rpc_set_waitqueue_priority(queue
, queue
->maxpriority
);
238 rpc_set_waitqueue_cookie(queue
, 0);
241 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue
*queue
, const char *qname
, int maxprio
)
245 spin_lock_init(&queue
->lock
);
246 for (i
= 0; i
< ARRAY_SIZE(queue
->tasks
); i
++)
247 INIT_LIST_HEAD(&queue
->tasks
[i
]);
248 queue
->maxpriority
= maxprio
;
249 rpc_reset_waitqueue_priority(queue
);
255 void rpc_init_priority_wait_queue(struct rpc_wait_queue
*queue
, const char *qname
)
257 __rpc_init_priority_wait_queue(queue
, qname
, RPC_PRIORITY_HIGH
);
260 void rpc_init_wait_queue(struct rpc_wait_queue
*queue
, const char *qname
)
262 __rpc_init_priority_wait_queue(queue
, qname
, 0);
264 EXPORT_SYMBOL(rpc_init_wait_queue
);
266 static int rpc_wait_bit_interruptible(void *word
)
268 if (signal_pending(current
))
275 * Mark an RPC call as having completed by clearing the 'active' bit
277 static inline void rpc_mark_complete_task(struct rpc_task
*task
)
279 rpc_clear_active(task
);
280 wake_up_bit(&task
->tk_runstate
, RPC_TASK_ACTIVE
);
284 * Allow callers to wait for completion of an RPC call
286 int __rpc_wait_for_completion_task(struct rpc_task
*task
, int (*action
)(void *))
289 action
= rpc_wait_bit_interruptible
;
290 return wait_on_bit(&task
->tk_runstate
, RPC_TASK_ACTIVE
,
291 action
, TASK_INTERRUPTIBLE
);
293 EXPORT_SYMBOL(__rpc_wait_for_completion_task
);
296 * Make an RPC task runnable.
298 * Note: If the task is ASYNC, this must be called with
299 * the spinlock held to protect the wait queue operation.
301 static void rpc_make_runnable(struct rpc_task
*task
)
305 BUG_ON(task
->tk_timeout_fn
);
306 do_ret
= rpc_test_and_set_running(task
);
307 rpc_clear_queued(task
);
310 if (RPC_IS_ASYNC(task
)) {
313 INIT_WORK(&task
->u
.tk_work
, rpc_async_schedule
, (void *)task
);
314 status
= queue_work(task
->tk_workqueue
, &task
->u
.tk_work
);
316 printk(KERN_WARNING
"RPC: failed to add task to queue: error: %d!\n", status
);
317 task
->tk_status
= status
;
321 wake_up_bit(&task
->tk_runstate
, RPC_TASK_QUEUED
);
325 * Place a newly initialized task on the workqueue.
328 rpc_schedule_run(struct rpc_task
*task
)
330 rpc_set_active(task
);
331 rpc_make_runnable(task
);
335 * Prepare for sleeping on a wait queue.
336 * By always appending tasks to the list we ensure FIFO behavior.
337 * NB: An RPC task will only receive interrupt-driven events as long
338 * as it's on a wait queue.
340 static void __rpc_sleep_on(struct rpc_wait_queue
*q
, struct rpc_task
*task
,
341 rpc_action action
, rpc_action timer
)
343 dprintk("RPC: %4d sleep_on(queue \"%s\" time %ld)\n", task
->tk_pid
,
344 rpc_qname(q
), jiffies
);
346 if (!RPC_IS_ASYNC(task
) && !RPC_IS_ACTIVATED(task
)) {
347 printk(KERN_ERR
"RPC: Inactive synchronous task put to sleep!\n");
351 /* Mark the task as being activated if so needed */
352 rpc_set_active(task
);
354 __rpc_add_wait_queue(q
, task
);
356 BUG_ON(task
->tk_callback
!= NULL
);
357 task
->tk_callback
= action
;
358 __rpc_add_timer(task
, timer
);
361 void rpc_sleep_on(struct rpc_wait_queue
*q
, struct rpc_task
*task
,
362 rpc_action action
, rpc_action timer
)
365 * Protect the queue operations.
367 spin_lock_bh(&q
->lock
);
368 __rpc_sleep_on(q
, task
, action
, timer
);
369 spin_unlock_bh(&q
->lock
);
373 * __rpc_do_wake_up_task - wake up a single rpc_task
374 * @task: task to be woken up
376 * Caller must hold queue->lock, and have cleared the task queued flag.
378 static void __rpc_do_wake_up_task(struct rpc_task
*task
)
380 dprintk("RPC: %4d __rpc_wake_up_task (now %ld)\n", task
->tk_pid
, jiffies
);
383 BUG_ON(task
->tk_magic
!= RPC_TASK_MAGIC_ID
);
385 /* Has the task been executed yet? If not, we cannot wake it up! */
386 if (!RPC_IS_ACTIVATED(task
)) {
387 printk(KERN_ERR
"RPC: Inactive task (%p) being woken up!\n", task
);
391 __rpc_disable_timer(task
);
392 __rpc_remove_wait_queue(task
);
394 rpc_make_runnable(task
);
396 dprintk("RPC: __rpc_wake_up_task done\n");
400 * Wake up the specified task
402 static void __rpc_wake_up_task(struct rpc_task
*task
)
404 if (rpc_start_wakeup(task
)) {
405 if (RPC_IS_QUEUED(task
))
406 __rpc_do_wake_up_task(task
);
407 rpc_finish_wakeup(task
);
412 * Default timeout handler if none specified by user
415 __rpc_default_timer(struct rpc_task
*task
)
417 dprintk("RPC: %d timeout (default timer)\n", task
->tk_pid
);
418 task
->tk_status
= -ETIMEDOUT
;
419 rpc_wake_up_task(task
);
423 * Wake up the specified task
425 void rpc_wake_up_task(struct rpc_task
*task
)
427 if (rpc_start_wakeup(task
)) {
428 if (RPC_IS_QUEUED(task
)) {
429 struct rpc_wait_queue
*queue
= task
->u
.tk_wait
.rpc_waitq
;
431 spin_lock_bh(&queue
->lock
);
432 __rpc_do_wake_up_task(task
);
433 spin_unlock_bh(&queue
->lock
);
435 rpc_finish_wakeup(task
);
440 * Wake up the next task on a priority queue.
442 static struct rpc_task
* __rpc_wake_up_next_priority(struct rpc_wait_queue
*queue
)
445 struct rpc_task
*task
;
448 * Service a batch of tasks from a single cookie.
450 q
= &queue
->tasks
[queue
->priority
];
451 if (!list_empty(q
)) {
452 task
= list_entry(q
->next
, struct rpc_task
, u
.tk_wait
.list
);
453 if (queue
->cookie
== task
->tk_cookie
) {
456 list_move_tail(&task
->u
.tk_wait
.list
, q
);
459 * Check if we need to switch queues.
466 * Service the next queue.
469 if (q
== &queue
->tasks
[0])
470 q
= &queue
->tasks
[queue
->maxpriority
];
473 if (!list_empty(q
)) {
474 task
= list_entry(q
->next
, struct rpc_task
, u
.tk_wait
.list
);
477 } while (q
!= &queue
->tasks
[queue
->priority
]);
479 rpc_reset_waitqueue_priority(queue
);
483 rpc_set_waitqueue_priority(queue
, (unsigned int)(q
- &queue
->tasks
[0]));
485 rpc_set_waitqueue_cookie(queue
, task
->tk_cookie
);
487 __rpc_wake_up_task(task
);
492 * Wake up the next task on the wait queue.
494 struct rpc_task
* rpc_wake_up_next(struct rpc_wait_queue
*queue
)
496 struct rpc_task
*task
= NULL
;
498 dprintk("RPC: wake_up_next(%p \"%s\")\n", queue
, rpc_qname(queue
));
499 spin_lock_bh(&queue
->lock
);
500 if (RPC_IS_PRIORITY(queue
))
501 task
= __rpc_wake_up_next_priority(queue
);
503 task_for_first(task
, &queue
->tasks
[0])
504 __rpc_wake_up_task(task
);
506 spin_unlock_bh(&queue
->lock
);
512 * rpc_wake_up - wake up all rpc_tasks
513 * @queue: rpc_wait_queue on which the tasks are sleeping
517 void rpc_wake_up(struct rpc_wait_queue
*queue
)
519 struct rpc_task
*task
, *next
;
520 struct list_head
*head
;
522 spin_lock_bh(&queue
->lock
);
523 head
= &queue
->tasks
[queue
->maxpriority
];
525 list_for_each_entry_safe(task
, next
, head
, u
.tk_wait
.list
)
526 __rpc_wake_up_task(task
);
527 if (head
== &queue
->tasks
[0])
531 spin_unlock_bh(&queue
->lock
);
535 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
536 * @queue: rpc_wait_queue on which the tasks are sleeping
537 * @status: status value to set
541 void rpc_wake_up_status(struct rpc_wait_queue
*queue
, int status
)
543 struct rpc_task
*task
, *next
;
544 struct list_head
*head
;
546 spin_lock_bh(&queue
->lock
);
547 head
= &queue
->tasks
[queue
->maxpriority
];
549 list_for_each_entry_safe(task
, next
, head
, u
.tk_wait
.list
) {
550 task
->tk_status
= status
;
551 __rpc_wake_up_task(task
);
553 if (head
== &queue
->tasks
[0])
557 spin_unlock_bh(&queue
->lock
);
561 * Run a task at a later time
563 static void __rpc_atrun(struct rpc_task
*);
565 rpc_delay(struct rpc_task
*task
, unsigned long delay
)
567 task
->tk_timeout
= delay
;
568 rpc_sleep_on(&delay_queue
, task
, NULL
, __rpc_atrun
);
572 __rpc_atrun(struct rpc_task
*task
)
575 rpc_wake_up_task(task
);
579 * Helper to call task->tk_ops->rpc_call_prepare
581 static void rpc_prepare_task(struct rpc_task
*task
)
583 task
->tk_ops
->rpc_call_prepare(task
, task
->tk_calldata
);
587 * Helper that calls task->tk_ops->rpc_call_done if it exists
589 void rpc_exit_task(struct rpc_task
*task
)
591 task
->tk_action
= NULL
;
592 if (task
->tk_ops
->rpc_call_done
!= NULL
) {
593 task
->tk_ops
->rpc_call_done(task
, task
->tk_calldata
);
594 if (task
->tk_action
!= NULL
) {
595 WARN_ON(RPC_ASSASSINATED(task
));
596 /* Always release the RPC slot and buffer memory */
601 EXPORT_SYMBOL(rpc_exit_task
);
604 * This is the RPC `scheduler' (or rather, the finite state machine).
606 static int __rpc_execute(struct rpc_task
*task
)
610 dprintk("RPC: %4d rpc_execute flgs %x\n",
611 task
->tk_pid
, task
->tk_flags
);
613 BUG_ON(RPC_IS_QUEUED(task
));
617 * Garbage collection of pending timers...
619 rpc_delete_timer(task
);
622 * Execute any pending callback.
624 if (RPC_DO_CALLBACK(task
)) {
625 /* Define a callback save pointer */
626 void (*save_callback
)(struct rpc_task
*);
629 * If a callback exists, save it, reset it,
631 * The save is needed to stop from resetting
632 * another callback set within the callback handler
635 save_callback
=task
->tk_callback
;
636 task
->tk_callback
=NULL
;
643 * Perform the next FSM step.
644 * tk_action may be NULL when the task has been killed
647 if (!RPC_IS_QUEUED(task
)) {
648 if (task
->tk_action
== NULL
)
651 task
->tk_action(task
);
656 * Lockless check for whether task is sleeping or not.
658 if (!RPC_IS_QUEUED(task
))
660 rpc_clear_running(task
);
661 if (RPC_IS_ASYNC(task
)) {
662 /* Careful! we may have raced... */
663 if (RPC_IS_QUEUED(task
))
665 if (rpc_test_and_set_running(task
))
670 /* sync task: sleep here */
671 dprintk("RPC: %4d sync task going to sleep\n", task
->tk_pid
);
672 /* Note: Caller should be using rpc_clnt_sigmask() */
673 status
= out_of_line_wait_on_bit(&task
->tk_runstate
,
674 RPC_TASK_QUEUED
, rpc_wait_bit_interruptible
,
676 if (status
== -ERESTARTSYS
) {
678 * When a sync task receives a signal, it exits with
679 * -ERESTARTSYS. In order to catch any callbacks that
680 * clean up after sleeping on some queue, we don't
681 * break the loop here, but go around once more.
683 dprintk("RPC: %4d got signal\n", task
->tk_pid
);
684 task
->tk_flags
|= RPC_TASK_KILLED
;
685 rpc_exit(task
, -ERESTARTSYS
);
686 rpc_wake_up_task(task
);
688 rpc_set_running(task
);
689 dprintk("RPC: %4d sync task resuming\n", task
->tk_pid
);
692 dprintk("RPC: %4d, return %d, status %d\n", task
->tk_pid
, status
, task
->tk_status
);
693 /* Wake up anyone who is waiting for task completion */
694 rpc_mark_complete_task(task
);
695 /* Release all resources associated with the task */
696 rpc_release_task(task
);
701 * User-visible entry point to the scheduler.
703 * This may be called recursively if e.g. an async NFS task updates
704 * the attributes and finds that dirty pages must be flushed.
705 * NOTE: Upon exit of this function the task is guaranteed to be
706 * released. In particular note that tk_release() will have
707 * been called, so your task memory may have been freed.
710 rpc_execute(struct rpc_task
*task
)
712 rpc_set_active(task
);
713 rpc_set_running(task
);
714 return __rpc_execute(task
);
717 static void rpc_async_schedule(void *arg
)
719 __rpc_execute((struct rpc_task
*)arg
);
723 * rpc_malloc - allocate an RPC buffer
724 * @task: RPC task that will use this buffer
725 * @size: requested byte size
727 * We try to ensure that some NFS reads and writes can always proceed
728 * by using a mempool when allocating 'small' buffers.
729 * In order to avoid memory starvation triggering more writebacks of
730 * NFS requests, we use GFP_NOFS rather than GFP_KERNEL.
732 void * rpc_malloc(struct rpc_task
*task
, size_t size
)
734 struct rpc_rqst
*req
= task
->tk_rqstp
;
737 if (task
->tk_flags
& RPC_TASK_SWAPPER
)
742 if (size
> RPC_BUFFER_MAXSIZE
) {
743 req
->rq_buffer
= kmalloc(size
, gfp
);
745 req
->rq_bufsize
= size
;
747 req
->rq_buffer
= mempool_alloc(rpc_buffer_mempool
, gfp
);
749 req
->rq_bufsize
= RPC_BUFFER_MAXSIZE
;
751 return req
->rq_buffer
;
755 * rpc_free - free buffer allocated via rpc_malloc
756 * @task: RPC task with a buffer to be freed
759 void rpc_free(struct rpc_task
*task
)
761 struct rpc_rqst
*req
= task
->tk_rqstp
;
763 if (req
->rq_buffer
) {
764 if (req
->rq_bufsize
== RPC_BUFFER_MAXSIZE
)
765 mempool_free(req
->rq_buffer
, rpc_buffer_mempool
);
767 kfree(req
->rq_buffer
);
768 req
->rq_buffer
= NULL
;
774 * Creation and deletion of RPC task structures
776 void rpc_init_task(struct rpc_task
*task
, struct rpc_clnt
*clnt
, int flags
, const struct rpc_call_ops
*tk_ops
, void *calldata
)
778 memset(task
, 0, sizeof(*task
));
779 init_timer(&task
->tk_timer
);
780 task
->tk_timer
.data
= (unsigned long) task
;
781 task
->tk_timer
.function
= (void (*)(unsigned long)) rpc_run_timer
;
782 atomic_set(&task
->tk_count
, 1);
783 task
->tk_client
= clnt
;
784 task
->tk_flags
= flags
;
785 task
->tk_ops
= tk_ops
;
786 if (tk_ops
->rpc_call_prepare
!= NULL
)
787 task
->tk_action
= rpc_prepare_task
;
788 task
->tk_calldata
= calldata
;
790 /* Initialize retry counters */
791 task
->tk_garb_retry
= 2;
792 task
->tk_cred_retry
= 2;
794 task
->tk_priority
= RPC_PRIORITY_NORMAL
;
795 task
->tk_cookie
= (unsigned long)current
;
797 /* Initialize workqueue for async tasks */
798 task
->tk_workqueue
= rpciod_workqueue
;
801 atomic_inc(&clnt
->cl_users
);
802 if (clnt
->cl_softrtry
)
803 task
->tk_flags
|= RPC_TASK_SOFT
;
805 task
->tk_flags
|= RPC_TASK_NOINTR
;
809 task
->tk_magic
= RPC_TASK_MAGIC_ID
;
810 task
->tk_pid
= rpc_task_id
++;
812 /* Add to global list of all tasks */
813 spin_lock(&rpc_sched_lock
);
814 list_add_tail(&task
->tk_task
, &all_tasks
);
815 spin_unlock(&rpc_sched_lock
);
817 BUG_ON(task
->tk_ops
== NULL
);
819 dprintk("RPC: %4d new task procpid %d\n", task
->tk_pid
,
823 static struct rpc_task
*
826 return (struct rpc_task
*)mempool_alloc(rpc_task_mempool
, GFP_NOFS
);
829 static void rpc_free_task(struct rpc_task
*task
)
831 dprintk("RPC: %4d freeing task\n", task
->tk_pid
);
832 mempool_free(task
, rpc_task_mempool
);
836 * Create a new task for the specified client. We have to
837 * clean up after an allocation failure, as the client may
838 * have specified "oneshot".
840 struct rpc_task
*rpc_new_task(struct rpc_clnt
*clnt
, int flags
, const struct rpc_call_ops
*tk_ops
, void *calldata
)
842 struct rpc_task
*task
;
844 task
= rpc_alloc_task();
848 rpc_init_task(task
, clnt
, flags
, tk_ops
, calldata
);
850 dprintk("RPC: %4d allocated task\n", task
->tk_pid
);
851 task
->tk_flags
|= RPC_TASK_DYNAMIC
;
856 /* Check whether to release the client */
858 printk("rpc_new_task: failed, users=%d, oneshot=%d\n",
859 atomic_read(&clnt
->cl_users
), clnt
->cl_oneshot
);
860 atomic_inc(&clnt
->cl_users
); /* pretend we were used ... */
861 rpc_release_client(clnt
);
866 void rpc_release_task(struct rpc_task
*task
)
868 const struct rpc_call_ops
*tk_ops
= task
->tk_ops
;
869 void *calldata
= task
->tk_calldata
;
872 BUG_ON(task
->tk_magic
!= RPC_TASK_MAGIC_ID
);
874 if (!atomic_dec_and_test(&task
->tk_count
))
876 dprintk("RPC: %4d release task\n", task
->tk_pid
);
878 /* Remove from global task list */
879 spin_lock(&rpc_sched_lock
);
880 list_del(&task
->tk_task
);
881 spin_unlock(&rpc_sched_lock
);
883 BUG_ON (RPC_IS_QUEUED(task
));
885 /* Synchronously delete any running timer */
886 rpc_delete_timer(task
);
888 /* Release resources */
891 if (task
->tk_msg
.rpc_cred
)
892 rpcauth_unbindcred(task
);
893 if (task
->tk_client
) {
894 rpc_release_client(task
->tk_client
);
895 task
->tk_client
= NULL
;
901 if (task
->tk_flags
& RPC_TASK_DYNAMIC
)
903 if (tk_ops
->rpc_release
)
904 tk_ops
->rpc_release(calldata
);
908 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
909 * @clnt: pointer to RPC client
912 * @data: user call data
914 struct rpc_task
*rpc_run_task(struct rpc_clnt
*clnt
, int flags
,
915 const struct rpc_call_ops
*ops
,
918 struct rpc_task
*task
;
919 task
= rpc_new_task(clnt
, flags
, ops
, data
);
921 return ERR_PTR(-ENOMEM
);
922 atomic_inc(&task
->tk_count
);
926 EXPORT_SYMBOL(rpc_run_task
);
929 * rpc_find_parent - find the parent of a child task.
931 * @parent: parent task
933 * Checks that the parent task is still sleeping on the
934 * queue 'childq'. If so returns a pointer to the parent.
935 * Upon failure returns NULL.
937 * Caller must hold childq.lock
939 static inline struct rpc_task
*rpc_find_parent(struct rpc_task
*child
, struct rpc_task
*parent
)
941 struct rpc_task
*task
;
942 struct list_head
*le
;
944 task_for_each(task
, le
, &childq
.tasks
[0])
951 static void rpc_child_exit(struct rpc_task
*child
, void *calldata
)
953 struct rpc_task
*parent
;
955 spin_lock_bh(&childq
.lock
);
956 if ((parent
= rpc_find_parent(child
, calldata
)) != NULL
) {
957 parent
->tk_status
= child
->tk_status
;
958 __rpc_wake_up_task(parent
);
960 spin_unlock_bh(&childq
.lock
);
963 static const struct rpc_call_ops rpc_child_ops
= {
964 .rpc_call_done
= rpc_child_exit
,
968 * Note: rpc_new_task releases the client after a failure.
971 rpc_new_child(struct rpc_clnt
*clnt
, struct rpc_task
*parent
)
973 struct rpc_task
*task
;
975 task
= rpc_new_task(clnt
, RPC_TASK_ASYNC
| RPC_TASK_CHILD
, &rpc_child_ops
, parent
);
981 parent
->tk_status
= -ENOMEM
;
985 void rpc_run_child(struct rpc_task
*task
, struct rpc_task
*child
, rpc_action func
)
987 spin_lock_bh(&childq
.lock
);
988 /* N.B. Is it possible for the child to have already finished? */
989 __rpc_sleep_on(&childq
, task
, func
, NULL
);
990 rpc_schedule_run(child
);
991 spin_unlock_bh(&childq
.lock
);
995 * Kill all tasks for the given client.
996 * XXX: kill their descendants as well?
998 void rpc_killall_tasks(struct rpc_clnt
*clnt
)
1000 struct rpc_task
*rovr
;
1001 struct list_head
*le
;
1003 dprintk("RPC: killing all tasks for client %p\n", clnt
);
1006 * Spin lock all_tasks to prevent changes...
1008 spin_lock(&rpc_sched_lock
);
1009 alltask_for_each(rovr
, le
, &all_tasks
) {
1010 if (! RPC_IS_ACTIVATED(rovr
))
1012 if (!clnt
|| rovr
->tk_client
== clnt
) {
1013 rovr
->tk_flags
|= RPC_TASK_KILLED
;
1014 rpc_exit(rovr
, -EIO
);
1015 rpc_wake_up_task(rovr
);
1018 spin_unlock(&rpc_sched_lock
);
1021 static DECLARE_MUTEX_LOCKED(rpciod_running
);
1023 static void rpciod_killall(void)
1025 unsigned long flags
;
1027 while (!list_empty(&all_tasks
)) {
1028 clear_thread_flag(TIF_SIGPENDING
);
1029 rpc_killall_tasks(NULL
);
1030 flush_workqueue(rpciod_workqueue
);
1031 if (!list_empty(&all_tasks
)) {
1032 dprintk("rpciod_killall: waiting for tasks to exit\n");
1037 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
1038 recalc_sigpending();
1039 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
1043 * Start up the rpciod process if it's not already running.
1048 struct workqueue_struct
*wq
;
1051 mutex_lock(&rpciod_mutex
);
1052 dprintk("rpciod_up: users %d\n", rpciod_users
);
1054 if (rpciod_workqueue
)
1057 * If there's no pid, we should be the first user.
1059 if (rpciod_users
> 1)
1060 printk(KERN_WARNING
"rpciod_up: no workqueue, %d users??\n", rpciod_users
);
1062 * Create the rpciod thread and wait for it to start.
1065 wq
= create_workqueue("rpciod");
1067 printk(KERN_WARNING
"rpciod_up: create workqueue failed, error=%d\n", error
);
1071 rpciod_workqueue
= wq
;
1074 mutex_unlock(&rpciod_mutex
);
1081 mutex_lock(&rpciod_mutex
);
1082 dprintk("rpciod_down sema %d\n", rpciod_users
);
1087 printk(KERN_WARNING
"rpciod_down: no users??\n");
1089 if (!rpciod_workqueue
) {
1090 dprintk("rpciod_down: Nothing to do!\n");
1095 destroy_workqueue(rpciod_workqueue
);
1096 rpciod_workqueue
= NULL
;
1098 mutex_unlock(&rpciod_mutex
);
1102 void rpc_show_tasks(void)
1104 struct list_head
*le
;
1107 spin_lock(&rpc_sched_lock
);
1108 if (list_empty(&all_tasks
)) {
1109 spin_unlock(&rpc_sched_lock
);
1112 printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1113 "-rpcwait -action- ---ops--\n");
1114 alltask_for_each(t
, le
, &all_tasks
) {
1115 const char *rpc_waitq
= "none";
1117 if (RPC_IS_QUEUED(t
))
1118 rpc_waitq
= rpc_qname(t
->u
.tk_wait
.rpc_waitq
);
1120 printk("%05d %04d %04x %06d %8p %6d %8p %08ld %8s %8p %8p\n",
1122 (t
->tk_msg
.rpc_proc
? t
->tk_msg
.rpc_proc
->p_proc
: -1),
1123 t
->tk_flags
, t
->tk_status
,
1125 (t
->tk_client
? t
->tk_client
->cl_prog
: 0),
1126 t
->tk_rqstp
, t
->tk_timeout
,
1128 t
->tk_action
, t
->tk_ops
);
1130 spin_unlock(&rpc_sched_lock
);
1135 rpc_destroy_mempool(void)
1137 if (rpc_buffer_mempool
)
1138 mempool_destroy(rpc_buffer_mempool
);
1139 if (rpc_task_mempool
)
1140 mempool_destroy(rpc_task_mempool
);
1141 if (rpc_task_slabp
&& kmem_cache_destroy(rpc_task_slabp
))
1142 printk(KERN_INFO
"rpc_task: not all structures were freed\n");
1143 if (rpc_buffer_slabp
&& kmem_cache_destroy(rpc_buffer_slabp
))
1144 printk(KERN_INFO
"rpc_buffers: not all structures were freed\n");
1148 rpc_init_mempool(void)
1150 rpc_task_slabp
= kmem_cache_create("rpc_tasks",
1151 sizeof(struct rpc_task
),
1152 0, SLAB_HWCACHE_ALIGN
,
1154 if (!rpc_task_slabp
)
1156 rpc_buffer_slabp
= kmem_cache_create("rpc_buffers",
1158 0, SLAB_HWCACHE_ALIGN
,
1160 if (!rpc_buffer_slabp
)
1162 rpc_task_mempool
= mempool_create(RPC_TASK_POOLSIZE
,
1166 if (!rpc_task_mempool
)
1168 rpc_buffer_mempool
= mempool_create(RPC_BUFFER_POOLSIZE
,
1172 if (!rpc_buffer_mempool
)
1176 rpc_destroy_mempool();