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/spinlock.h>
20 #include <linux/mutex.h>
22 #include <linux/sunrpc/clnt.h>
27 #define RPCDBG_FACILITY RPCDBG_SCHED
31 * RPC slabs and memory pools
33 #define RPC_BUFFER_MAXSIZE (2048)
34 #define RPC_BUFFER_POOLSIZE (8)
35 #define RPC_TASK_POOLSIZE (8)
36 static struct kmem_cache
*rpc_task_slabp __read_mostly
;
37 static struct kmem_cache
*rpc_buffer_slabp __read_mostly
;
38 static mempool_t
*rpc_task_mempool __read_mostly
;
39 static mempool_t
*rpc_buffer_mempool __read_mostly
;
41 static void rpc_async_schedule(struct work_struct
*);
42 static void rpc_release_task(struct rpc_task
*task
);
43 static void __rpc_queue_timer_fn(unsigned long ptr
);
46 * RPC tasks sit here while waiting for conditions to improve.
48 static struct rpc_wait_queue delay_queue
;
51 * rpciod-related stuff
53 struct workqueue_struct
*rpciod_workqueue
;
56 * Disable the timer for a given RPC task. Should be called with
57 * queue->lock and bh_disabled in order to avoid races within
61 __rpc_disable_timer(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
63 if (task
->tk_timeout
== 0)
65 dprintk("RPC: %5u disabling timer\n", task
->tk_pid
);
67 list_del(&task
->u
.tk_wait
.timer_list
);
68 if (list_empty(&queue
->timer_list
.list
))
69 del_timer(&queue
->timer_list
.timer
);
73 rpc_set_queue_timer(struct rpc_wait_queue
*queue
, unsigned long expires
)
75 queue
->timer_list
.expires
= expires
;
76 mod_timer(&queue
->timer_list
.timer
, expires
);
80 * Set up a timer for the current task.
83 __rpc_add_timer(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
85 if (!task
->tk_timeout
)
88 dprintk("RPC: %5u setting alarm for %lu ms\n",
89 task
->tk_pid
, task
->tk_timeout
* 1000 / HZ
);
91 task
->u
.tk_wait
.expires
= jiffies
+ task
->tk_timeout
;
92 if (list_empty(&queue
->timer_list
.list
) || time_before(task
->u
.tk_wait
.expires
, queue
->timer_list
.expires
))
93 rpc_set_queue_timer(queue
, task
->u
.tk_wait
.expires
);
94 list_add(&task
->u
.tk_wait
.timer_list
, &queue
->timer_list
.list
);
98 * Add new request to a priority queue.
100 static void __rpc_add_wait_queue_priority(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
105 INIT_LIST_HEAD(&task
->u
.tk_wait
.links
);
106 q
= &queue
->tasks
[task
->tk_priority
];
107 if (unlikely(task
->tk_priority
> queue
->maxpriority
))
108 q
= &queue
->tasks
[queue
->maxpriority
];
109 list_for_each_entry(t
, q
, u
.tk_wait
.list
) {
110 if (t
->tk_owner
== task
->tk_owner
) {
111 list_add_tail(&task
->u
.tk_wait
.list
, &t
->u
.tk_wait
.links
);
115 list_add_tail(&task
->u
.tk_wait
.list
, q
);
119 * Add new request to wait queue.
121 * Swapper tasks always get inserted at the head of the queue.
122 * This should avoid many nasty memory deadlocks and hopefully
123 * improve overall performance.
124 * Everyone else gets appended to the queue to ensure proper FIFO behavior.
126 static void __rpc_add_wait_queue(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
128 BUG_ON (RPC_IS_QUEUED(task
));
130 if (RPC_IS_PRIORITY(queue
))
131 __rpc_add_wait_queue_priority(queue
, task
);
132 else if (RPC_IS_SWAPPER(task
))
133 list_add(&task
->u
.tk_wait
.list
, &queue
->tasks
[0]);
135 list_add_tail(&task
->u
.tk_wait
.list
, &queue
->tasks
[0]);
136 task
->tk_waitqueue
= queue
;
138 rpc_set_queued(task
);
140 dprintk("RPC: %5u added to queue %p \"%s\"\n",
141 task
->tk_pid
, queue
, rpc_qname(queue
));
145 * Remove request from a priority queue.
147 static void __rpc_remove_wait_queue_priority(struct rpc_task
*task
)
151 if (!list_empty(&task
->u
.tk_wait
.links
)) {
152 t
= list_entry(task
->u
.tk_wait
.links
.next
, struct rpc_task
, u
.tk_wait
.list
);
153 list_move(&t
->u
.tk_wait
.list
, &task
->u
.tk_wait
.list
);
154 list_splice_init(&task
->u
.tk_wait
.links
, &t
->u
.tk_wait
.links
);
159 * Remove request from queue.
160 * Note: must be called with spin lock held.
162 static void __rpc_remove_wait_queue(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
164 __rpc_disable_timer(queue
, task
);
165 if (RPC_IS_PRIORITY(queue
))
166 __rpc_remove_wait_queue_priority(task
);
167 list_del(&task
->u
.tk_wait
.list
);
169 dprintk("RPC: %5u removed from queue %p \"%s\"\n",
170 task
->tk_pid
, queue
, rpc_qname(queue
));
173 static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue
*queue
, int priority
)
175 queue
->priority
= priority
;
176 queue
->count
= 1 << (priority
* 2);
179 static inline void rpc_set_waitqueue_owner(struct rpc_wait_queue
*queue
, pid_t pid
)
182 queue
->nr
= RPC_BATCH_COUNT
;
185 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue
*queue
)
187 rpc_set_waitqueue_priority(queue
, queue
->maxpriority
);
188 rpc_set_waitqueue_owner(queue
, 0);
191 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue
*queue
, const char *qname
, unsigned char nr_queues
)
195 spin_lock_init(&queue
->lock
);
196 for (i
= 0; i
< ARRAY_SIZE(queue
->tasks
); i
++)
197 INIT_LIST_HEAD(&queue
->tasks
[i
]);
198 queue
->maxpriority
= nr_queues
- 1;
199 rpc_reset_waitqueue_priority(queue
);
201 setup_timer(&queue
->timer_list
.timer
, __rpc_queue_timer_fn
, (unsigned long)queue
);
202 INIT_LIST_HEAD(&queue
->timer_list
.list
);
208 void rpc_init_priority_wait_queue(struct rpc_wait_queue
*queue
, const char *qname
)
210 __rpc_init_priority_wait_queue(queue
, qname
, RPC_NR_PRIORITY
);
212 EXPORT_SYMBOL_GPL(rpc_init_priority_wait_queue
);
214 void rpc_init_wait_queue(struct rpc_wait_queue
*queue
, const char *qname
)
216 __rpc_init_priority_wait_queue(queue
, qname
, 1);
218 EXPORT_SYMBOL_GPL(rpc_init_wait_queue
);
220 void rpc_destroy_wait_queue(struct rpc_wait_queue
*queue
)
222 del_timer_sync(&queue
->timer_list
.timer
);
224 EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue
);
226 static int rpc_wait_bit_killable(void *word
)
228 if (fatal_signal_pending(current
))
235 static void rpc_task_set_debuginfo(struct rpc_task
*task
)
237 static atomic_t rpc_pid
;
239 task
->tk_pid
= atomic_inc_return(&rpc_pid
);
242 static inline void rpc_task_set_debuginfo(struct rpc_task
*task
)
247 static void rpc_set_active(struct rpc_task
*task
)
249 rpc_task_set_debuginfo(task
);
250 set_bit(RPC_TASK_ACTIVE
, &task
->tk_runstate
);
254 * Mark an RPC call as having completed by clearing the 'active' bit
255 * and then waking up all tasks that were sleeping.
257 static int rpc_complete_task(struct rpc_task
*task
)
259 void *m
= &task
->tk_runstate
;
260 wait_queue_head_t
*wq
= bit_waitqueue(m
, RPC_TASK_ACTIVE
);
261 struct wait_bit_key k
= __WAIT_BIT_KEY_INITIALIZER(m
, RPC_TASK_ACTIVE
);
265 spin_lock_irqsave(&wq
->lock
, flags
);
266 clear_bit(RPC_TASK_ACTIVE
, &task
->tk_runstate
);
267 ret
= atomic_dec_and_test(&task
->tk_count
);
268 if (waitqueue_active(wq
))
269 __wake_up_locked_key(wq
, TASK_NORMAL
, &k
);
270 spin_unlock_irqrestore(&wq
->lock
, flags
);
275 * Allow callers to wait for completion of an RPC call
277 * Note the use of out_of_line_wait_on_bit() rather than wait_on_bit()
278 * to enforce taking of the wq->lock and hence avoid races with
279 * rpc_complete_task().
281 int __rpc_wait_for_completion_task(struct rpc_task
*task
, int (*action
)(void *))
284 action
= rpc_wait_bit_killable
;
285 return out_of_line_wait_on_bit(&task
->tk_runstate
, RPC_TASK_ACTIVE
,
286 action
, TASK_KILLABLE
);
288 EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task
);
291 * Make an RPC task runnable.
293 * Note: If the task is ASYNC, this must be called with
294 * the spinlock held to protect the wait queue operation.
296 static void rpc_make_runnable(struct rpc_task
*task
)
298 rpc_clear_queued(task
);
299 if (rpc_test_and_set_running(task
))
301 if (RPC_IS_ASYNC(task
)) {
302 INIT_WORK(&task
->u
.tk_work
, rpc_async_schedule
);
303 queue_work(rpciod_workqueue
, &task
->u
.tk_work
);
305 wake_up_bit(&task
->tk_runstate
, RPC_TASK_QUEUED
);
309 * Prepare for sleeping on a wait queue.
310 * By always appending tasks to the list we ensure FIFO behavior.
311 * NB: An RPC task will only receive interrupt-driven events as long
312 * as it's on a wait queue.
314 static void __rpc_sleep_on(struct rpc_wait_queue
*q
, struct rpc_task
*task
,
317 dprintk("RPC: %5u sleep_on(queue \"%s\" time %lu)\n",
318 task
->tk_pid
, rpc_qname(q
), jiffies
);
320 __rpc_add_wait_queue(q
, task
);
322 BUG_ON(task
->tk_callback
!= NULL
);
323 task
->tk_callback
= action
;
324 __rpc_add_timer(q
, task
);
327 void rpc_sleep_on(struct rpc_wait_queue
*q
, struct rpc_task
*task
,
330 /* We shouldn't ever put an inactive task to sleep */
331 BUG_ON(!RPC_IS_ACTIVATED(task
));
334 * Protect the queue operations.
336 spin_lock_bh(&q
->lock
);
337 __rpc_sleep_on(q
, task
, action
);
338 spin_unlock_bh(&q
->lock
);
340 EXPORT_SYMBOL_GPL(rpc_sleep_on
);
343 * __rpc_do_wake_up_task - wake up a single rpc_task
345 * @task: task to be woken up
347 * Caller must hold queue->lock, and have cleared the task queued flag.
349 static void __rpc_do_wake_up_task(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
351 dprintk("RPC: %5u __rpc_wake_up_task (now %lu)\n",
352 task
->tk_pid
, jiffies
);
354 /* Has the task been executed yet? If not, we cannot wake it up! */
355 if (!RPC_IS_ACTIVATED(task
)) {
356 printk(KERN_ERR
"RPC: Inactive task (%p) being woken up!\n", task
);
360 __rpc_remove_wait_queue(queue
, task
);
362 rpc_make_runnable(task
);
364 dprintk("RPC: __rpc_wake_up_task done\n");
368 * Wake up a queued task while the queue lock is being held
370 static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
372 if (RPC_IS_QUEUED(task
) && task
->tk_waitqueue
== queue
)
373 __rpc_do_wake_up_task(queue
, task
);
377 * Tests whether rpc queue is empty
379 int rpc_queue_empty(struct rpc_wait_queue
*queue
)
383 spin_lock_bh(&queue
->lock
);
385 spin_unlock_bh(&queue
->lock
);
388 EXPORT_SYMBOL_GPL(rpc_queue_empty
);
391 * Wake up a task on a specific queue
393 void rpc_wake_up_queued_task(struct rpc_wait_queue
*queue
, struct rpc_task
*task
)
395 spin_lock_bh(&queue
->lock
);
396 rpc_wake_up_task_queue_locked(queue
, task
);
397 spin_unlock_bh(&queue
->lock
);
399 EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task
);
402 * Wake up the next task on a priority queue.
404 static struct rpc_task
* __rpc_wake_up_next_priority(struct rpc_wait_queue
*queue
)
407 struct rpc_task
*task
;
410 * Service a batch of tasks from a single owner.
412 q
= &queue
->tasks
[queue
->priority
];
413 if (!list_empty(q
)) {
414 task
= list_entry(q
->next
, struct rpc_task
, u
.tk_wait
.list
);
415 if (queue
->owner
== task
->tk_owner
) {
418 list_move_tail(&task
->u
.tk_wait
.list
, q
);
421 * Check if we need to switch queues.
428 * Service the next queue.
431 if (q
== &queue
->tasks
[0])
432 q
= &queue
->tasks
[queue
->maxpriority
];
435 if (!list_empty(q
)) {
436 task
= list_entry(q
->next
, struct rpc_task
, u
.tk_wait
.list
);
439 } while (q
!= &queue
->tasks
[queue
->priority
]);
441 rpc_reset_waitqueue_priority(queue
);
445 rpc_set_waitqueue_priority(queue
, (unsigned int)(q
- &queue
->tasks
[0]));
447 rpc_set_waitqueue_owner(queue
, task
->tk_owner
);
449 rpc_wake_up_task_queue_locked(queue
, task
);
454 * Wake up the next task on the wait queue.
456 struct rpc_task
* rpc_wake_up_next(struct rpc_wait_queue
*queue
)
458 struct rpc_task
*task
= NULL
;
460 dprintk("RPC: wake_up_next(%p \"%s\")\n",
461 queue
, rpc_qname(queue
));
462 spin_lock_bh(&queue
->lock
);
463 if (RPC_IS_PRIORITY(queue
))
464 task
= __rpc_wake_up_next_priority(queue
);
466 task_for_first(task
, &queue
->tasks
[0])
467 rpc_wake_up_task_queue_locked(queue
, task
);
469 spin_unlock_bh(&queue
->lock
);
473 EXPORT_SYMBOL_GPL(rpc_wake_up_next
);
476 * rpc_wake_up - wake up all rpc_tasks
477 * @queue: rpc_wait_queue on which the tasks are sleeping
481 void rpc_wake_up(struct rpc_wait_queue
*queue
)
483 struct rpc_task
*task
, *next
;
484 struct list_head
*head
;
486 spin_lock_bh(&queue
->lock
);
487 head
= &queue
->tasks
[queue
->maxpriority
];
489 list_for_each_entry_safe(task
, next
, head
, u
.tk_wait
.list
)
490 rpc_wake_up_task_queue_locked(queue
, task
);
491 if (head
== &queue
->tasks
[0])
495 spin_unlock_bh(&queue
->lock
);
497 EXPORT_SYMBOL_GPL(rpc_wake_up
);
500 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
501 * @queue: rpc_wait_queue on which the tasks are sleeping
502 * @status: status value to set
506 void rpc_wake_up_status(struct rpc_wait_queue
*queue
, int status
)
508 struct rpc_task
*task
, *next
;
509 struct list_head
*head
;
511 spin_lock_bh(&queue
->lock
);
512 head
= &queue
->tasks
[queue
->maxpriority
];
514 list_for_each_entry_safe(task
, next
, head
, u
.tk_wait
.list
) {
515 task
->tk_status
= status
;
516 rpc_wake_up_task_queue_locked(queue
, task
);
518 if (head
== &queue
->tasks
[0])
522 spin_unlock_bh(&queue
->lock
);
524 EXPORT_SYMBOL_GPL(rpc_wake_up_status
);
526 static void __rpc_queue_timer_fn(unsigned long ptr
)
528 struct rpc_wait_queue
*queue
= (struct rpc_wait_queue
*)ptr
;
529 struct rpc_task
*task
, *n
;
530 unsigned long expires
, now
, timeo
;
532 spin_lock(&queue
->lock
);
533 expires
= now
= jiffies
;
534 list_for_each_entry_safe(task
, n
, &queue
->timer_list
.list
, u
.tk_wait
.timer_list
) {
535 timeo
= task
->u
.tk_wait
.expires
;
536 if (time_after_eq(now
, timeo
)) {
537 dprintk("RPC: %5u timeout\n", task
->tk_pid
);
538 task
->tk_status
= -ETIMEDOUT
;
539 rpc_wake_up_task_queue_locked(queue
, task
);
542 if (expires
== now
|| time_after(expires
, timeo
))
545 if (!list_empty(&queue
->timer_list
.list
))
546 rpc_set_queue_timer(queue
, expires
);
547 spin_unlock(&queue
->lock
);
550 static void __rpc_atrun(struct rpc_task
*task
)
556 * Run a task at a later time
558 void rpc_delay(struct rpc_task
*task
, unsigned long delay
)
560 task
->tk_timeout
= delay
;
561 rpc_sleep_on(&delay_queue
, task
, __rpc_atrun
);
563 EXPORT_SYMBOL_GPL(rpc_delay
);
566 * Helper to call task->tk_ops->rpc_call_prepare
568 void rpc_prepare_task(struct rpc_task
*task
)
570 task
->tk_ops
->rpc_call_prepare(task
, task
->tk_calldata
);
574 * Helper that calls task->tk_ops->rpc_call_done if it exists
576 void rpc_exit_task(struct rpc_task
*task
)
578 task
->tk_action
= NULL
;
579 if (task
->tk_ops
->rpc_call_done
!= NULL
) {
580 task
->tk_ops
->rpc_call_done(task
, task
->tk_calldata
);
581 if (task
->tk_action
!= NULL
) {
582 WARN_ON(RPC_ASSASSINATED(task
));
583 /* Always release the RPC slot and buffer memory */
589 void rpc_exit(struct rpc_task
*task
, int status
)
591 task
->tk_status
= status
;
592 task
->tk_action
= rpc_exit_task
;
593 if (RPC_IS_QUEUED(task
))
594 rpc_wake_up_queued_task(task
->tk_waitqueue
, task
);
596 EXPORT_SYMBOL_GPL(rpc_exit
);
598 void rpc_release_calldata(const struct rpc_call_ops
*ops
, void *calldata
)
600 if (ops
->rpc_release
!= NULL
)
601 ops
->rpc_release(calldata
);
605 * This is the RPC `scheduler' (or rather, the finite state machine).
607 static void __rpc_execute(struct rpc_task
*task
)
609 struct rpc_wait_queue
*queue
;
610 int task_is_async
= RPC_IS_ASYNC(task
);
613 dprintk("RPC: %5u __rpc_execute flags=0x%x\n",
614 task
->tk_pid
, task
->tk_flags
);
616 BUG_ON(RPC_IS_QUEUED(task
));
619 void (*do_action
)(struct rpc_task
*);
622 * Execute any pending callback first.
624 do_action
= task
->tk_callback
;
625 task
->tk_callback
= NULL
;
626 if (do_action
== NULL
) {
628 * Perform the next FSM step.
629 * tk_action may be NULL if the task has been killed.
630 * In particular, note that rpc_killall_tasks may
631 * do this at any time, so beware when dereferencing.
633 do_action
= task
->tk_action
;
634 if (do_action
== NULL
)
640 * Lockless check for whether task is sleeping or not.
642 if (!RPC_IS_QUEUED(task
))
645 * The queue->lock protects against races with
646 * rpc_make_runnable().
648 * Note that once we clear RPC_TASK_RUNNING on an asynchronous
649 * rpc_task, rpc_make_runnable() can assign it to a
650 * different workqueue. We therefore cannot assume that the
651 * rpc_task pointer may still be dereferenced.
653 queue
= task
->tk_waitqueue
;
654 spin_lock_bh(&queue
->lock
);
655 if (!RPC_IS_QUEUED(task
)) {
656 spin_unlock_bh(&queue
->lock
);
659 rpc_clear_running(task
);
660 spin_unlock_bh(&queue
->lock
);
664 /* sync task: sleep here */
665 dprintk("RPC: %5u sync task going to sleep\n", task
->tk_pid
);
666 status
= out_of_line_wait_on_bit(&task
->tk_runstate
,
667 RPC_TASK_QUEUED
, rpc_wait_bit_killable
,
669 if (status
== -ERESTARTSYS
) {
671 * When a sync task receives a signal, it exits with
672 * -ERESTARTSYS. In order to catch any callbacks that
673 * clean up after sleeping on some queue, we don't
674 * break the loop here, but go around once more.
676 dprintk("RPC: %5u got signal\n", task
->tk_pid
);
677 task
->tk_flags
|= RPC_TASK_KILLED
;
678 rpc_exit(task
, -ERESTARTSYS
);
680 rpc_set_running(task
);
681 dprintk("RPC: %5u sync task resuming\n", task
->tk_pid
);
684 dprintk("RPC: %5u return %d, status %d\n", task
->tk_pid
, status
,
686 /* Release all resources associated with the task */
687 rpc_release_task(task
);
691 * User-visible entry point to the scheduler.
693 * This may be called recursively if e.g. an async NFS task updates
694 * the attributes and finds that dirty pages must be flushed.
695 * NOTE: Upon exit of this function the task is guaranteed to be
696 * released. In particular note that tk_release() will have
697 * been called, so your task memory may have been freed.
699 void rpc_execute(struct rpc_task
*task
)
701 rpc_set_active(task
);
702 rpc_make_runnable(task
);
703 if (!RPC_IS_ASYNC(task
))
707 static void rpc_async_schedule(struct work_struct
*work
)
709 __rpc_execute(container_of(work
, struct rpc_task
, u
.tk_work
));
713 * rpc_malloc - allocate an RPC buffer
714 * @task: RPC task that will use this buffer
715 * @size: requested byte size
717 * To prevent rpciod from hanging, this allocator never sleeps,
718 * returning NULL if the request cannot be serviced immediately.
719 * The caller can arrange to sleep in a way that is safe for rpciod.
721 * Most requests are 'small' (under 2KiB) and can be serviced from a
722 * mempool, ensuring that NFS reads and writes can always proceed,
723 * and that there is good locality of reference for these buffers.
725 * In order to avoid memory starvation triggering more writebacks of
726 * NFS requests, we avoid using GFP_KERNEL.
728 void *rpc_malloc(struct rpc_task
*task
, size_t size
)
730 struct rpc_buffer
*buf
;
731 gfp_t gfp
= RPC_IS_SWAPPER(task
) ? GFP_ATOMIC
: GFP_NOWAIT
;
733 size
+= sizeof(struct rpc_buffer
);
734 if (size
<= RPC_BUFFER_MAXSIZE
)
735 buf
= mempool_alloc(rpc_buffer_mempool
, gfp
);
737 buf
= kmalloc(size
, gfp
);
743 dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
744 task
->tk_pid
, size
, buf
);
747 EXPORT_SYMBOL_GPL(rpc_malloc
);
750 * rpc_free - free buffer allocated via rpc_malloc
751 * @buffer: buffer to free
754 void rpc_free(void *buffer
)
757 struct rpc_buffer
*buf
;
762 buf
= container_of(buffer
, struct rpc_buffer
, data
);
765 dprintk("RPC: freeing buffer of size %zu at %p\n",
768 if (size
<= RPC_BUFFER_MAXSIZE
)
769 mempool_free(buf
, rpc_buffer_mempool
);
773 EXPORT_SYMBOL_GPL(rpc_free
);
776 * Creation and deletion of RPC task structures
778 static void rpc_init_task(struct rpc_task
*task
, const struct rpc_task_setup
*task_setup_data
)
780 memset(task
, 0, sizeof(*task
));
781 atomic_set(&task
->tk_count
, 1);
782 task
->tk_flags
= task_setup_data
->flags
;
783 task
->tk_ops
= task_setup_data
->callback_ops
;
784 task
->tk_calldata
= task_setup_data
->callback_data
;
785 INIT_LIST_HEAD(&task
->tk_task
);
787 /* Initialize retry counters */
788 task
->tk_garb_retry
= 2;
789 task
->tk_cred_retry
= 2;
790 task
->tk_rebind_retry
= 2;
792 task
->tk_priority
= task_setup_data
->priority
- RPC_PRIORITY_LOW
;
793 task
->tk_owner
= current
->tgid
;
795 /* Initialize workqueue for async tasks */
796 task
->tk_workqueue
= task_setup_data
->workqueue
;
798 if (task
->tk_ops
->rpc_call_prepare
!= NULL
)
799 task
->tk_action
= rpc_prepare_task
;
801 /* starting timestamp */
802 task
->tk_start
= ktime_get();
804 dprintk("RPC: new task initialized, procpid %u\n",
805 task_pid_nr(current
));
808 static struct rpc_task
*
811 return (struct rpc_task
*)mempool_alloc(rpc_task_mempool
, GFP_NOFS
);
815 * Create a new task for the specified client.
817 struct rpc_task
*rpc_new_task(const struct rpc_task_setup
*setup_data
)
819 struct rpc_task
*task
= setup_data
->task
;
820 unsigned short flags
= 0;
823 task
= rpc_alloc_task();
825 rpc_release_calldata(setup_data
->callback_ops
,
826 setup_data
->callback_data
);
827 return ERR_PTR(-ENOMEM
);
829 flags
= RPC_TASK_DYNAMIC
;
832 rpc_init_task(task
, setup_data
);
833 task
->tk_flags
|= flags
;
834 dprintk("RPC: allocated task %p\n", task
);
838 static void rpc_free_task(struct rpc_task
*task
)
840 const struct rpc_call_ops
*tk_ops
= task
->tk_ops
;
841 void *calldata
= task
->tk_calldata
;
843 if (task
->tk_flags
& RPC_TASK_DYNAMIC
) {
844 dprintk("RPC: %5u freeing task\n", task
->tk_pid
);
845 mempool_free(task
, rpc_task_mempool
);
847 rpc_release_calldata(tk_ops
, calldata
);
850 static void rpc_async_release(struct work_struct
*work
)
852 rpc_free_task(container_of(work
, struct rpc_task
, u
.tk_work
));
855 static void rpc_release_resources_task(struct rpc_task
*task
)
859 if (task
->tk_msg
.rpc_cred
) {
860 put_rpccred(task
->tk_msg
.rpc_cred
);
861 task
->tk_msg
.rpc_cred
= NULL
;
863 rpc_task_release_client(task
);
866 static void rpc_final_put_task(struct rpc_task
*task
,
867 struct workqueue_struct
*q
)
870 INIT_WORK(&task
->u
.tk_work
, rpc_async_release
);
871 queue_work(q
, &task
->u
.tk_work
);
876 static void rpc_do_put_task(struct rpc_task
*task
, struct workqueue_struct
*q
)
878 if (atomic_dec_and_test(&task
->tk_count
)) {
879 rpc_release_resources_task(task
);
880 rpc_final_put_task(task
, q
);
884 void rpc_put_task(struct rpc_task
*task
)
886 rpc_do_put_task(task
, NULL
);
888 EXPORT_SYMBOL_GPL(rpc_put_task
);
890 void rpc_put_task_async(struct rpc_task
*task
)
892 rpc_do_put_task(task
, task
->tk_workqueue
);
894 EXPORT_SYMBOL_GPL(rpc_put_task_async
);
896 static void rpc_release_task(struct rpc_task
*task
)
898 dprintk("RPC: %5u release task\n", task
->tk_pid
);
900 BUG_ON (RPC_IS_QUEUED(task
));
902 rpc_release_resources_task(task
);
905 * Note: at this point we have been removed from rpc_clnt->cl_tasks,
906 * so it should be safe to use task->tk_count as a test for whether
907 * or not any other processes still hold references to our rpc_task.
909 if (atomic_read(&task
->tk_count
) != 1 + !RPC_IS_ASYNC(task
)) {
910 /* Wake up anyone who may be waiting for task completion */
911 if (!rpc_complete_task(task
))
914 if (!atomic_dec_and_test(&task
->tk_count
))
917 rpc_final_put_task(task
, task
->tk_workqueue
);
922 return try_module_get(THIS_MODULE
) ? 0 : -EINVAL
;
925 void rpciod_down(void)
927 module_put(THIS_MODULE
);
931 * Start up the rpciod workqueue.
933 static int rpciod_start(void)
935 struct workqueue_struct
*wq
;
938 * Create the rpciod thread and wait for it to start.
940 dprintk("RPC: creating workqueue rpciod\n");
941 wq
= alloc_workqueue("rpciod", WQ_MEM_RECLAIM
, 0);
942 rpciod_workqueue
= wq
;
943 return rpciod_workqueue
!= NULL
;
946 static void rpciod_stop(void)
948 struct workqueue_struct
*wq
= NULL
;
950 if (rpciod_workqueue
== NULL
)
952 dprintk("RPC: destroying workqueue rpciod\n");
954 wq
= rpciod_workqueue
;
955 rpciod_workqueue
= NULL
;
956 destroy_workqueue(wq
);
960 rpc_destroy_mempool(void)
963 if (rpc_buffer_mempool
)
964 mempool_destroy(rpc_buffer_mempool
);
965 if (rpc_task_mempool
)
966 mempool_destroy(rpc_task_mempool
);
968 kmem_cache_destroy(rpc_task_slabp
);
969 if (rpc_buffer_slabp
)
970 kmem_cache_destroy(rpc_buffer_slabp
);
971 rpc_destroy_wait_queue(&delay_queue
);
975 rpc_init_mempool(void)
978 * The following is not strictly a mempool initialisation,
979 * but there is no harm in doing it here
981 rpc_init_wait_queue(&delay_queue
, "delayq");
985 rpc_task_slabp
= kmem_cache_create("rpc_tasks",
986 sizeof(struct rpc_task
),
987 0, SLAB_HWCACHE_ALIGN
,
991 rpc_buffer_slabp
= kmem_cache_create("rpc_buffers",
993 0, SLAB_HWCACHE_ALIGN
,
995 if (!rpc_buffer_slabp
)
997 rpc_task_mempool
= mempool_create_slab_pool(RPC_TASK_POOLSIZE
,
999 if (!rpc_task_mempool
)
1001 rpc_buffer_mempool
= mempool_create_slab_pool(RPC_BUFFER_POOLSIZE
,
1003 if (!rpc_buffer_mempool
)
1007 rpc_destroy_mempool();