blob: 99014516b73c7855294df0788c88f3d954a7214f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/net/sunrpc/sched.c
3 *
4 * Scheduling for synchronous and asynchronous RPC requests.
5 *
6 * Copyright (C) 1996 Olaf Kirch, <okir@monad.swb.de>
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08007 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * TCP NFS related read + write fixes
9 * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10 */
11
12#include <linux/module.h>
13
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>
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -080021#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <linux/sunrpc/clnt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#ifdef RPC_DEBUG
26#define RPCDBG_FACILITY RPCDBG_SCHED
27#define RPC_TASK_MAGIC_ID 0xf00baa
28static int rpc_task_id;
29#endif
30
31/*
32 * RPC slabs and memory pools
33 */
34#define RPC_BUFFER_MAXSIZE (2048)
35#define RPC_BUFFER_POOLSIZE (8)
36#define RPC_TASK_POOLSIZE (8)
Christoph Lametere18b8902006-12-06 20:33:20 -080037static struct kmem_cache *rpc_task_slabp __read_mostly;
38static struct kmem_cache *rpc_buffer_slabp __read_mostly;
Eric Dumazetba899662005-08-26 12:05:31 -070039static mempool_t *rpc_task_mempool __read_mostly;
40static mempool_t *rpc_buffer_mempool __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42static void __rpc_default_timer(struct rpc_task *task);
43static void rpciod_killall(void);
David Howells65f27f32006-11-22 14:55:48 +000044static void rpc_async_schedule(struct work_struct *);
Trond Myklebustbde8f002007-01-24 11:54:53 -080045static void rpc_release_task(struct rpc_task *task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
47/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 * RPC tasks sit here while waiting for conditions to improve.
49 */
50static RPC_WAITQ(delay_queue, "delayq");
51
52/*
53 * All RPC tasks are linked into this list
54 */
55static LIST_HEAD(all_tasks);
56
57/*
58 * rpciod-related stuff
59 */
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -080060static DEFINE_MUTEX(rpciod_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061static unsigned int rpciod_users;
Trond Myklebust24c5d9d2006-03-20 13:44:08 -050062struct workqueue_struct *rpciod_workqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64/*
65 * Spinlock for other critical sections of code.
66 */
67static DEFINE_SPINLOCK(rpc_sched_lock);
68
69/*
70 * Disable the timer for a given RPC task. Should be called with
71 * queue->lock and bh_disabled in order to avoid races within
72 * rpc_run_timer().
73 */
74static inline void
75__rpc_disable_timer(struct rpc_task *task)
76{
Chuck Lever46121cf2007-01-31 12:14:08 -050077 dprintk("RPC: %5u disabling timer\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 task->tk_timeout_fn = NULL;
79 task->tk_timeout = 0;
80}
81
82/*
83 * Run a timeout function.
84 * We use the callback in order to allow __rpc_wake_up_task()
85 * and friends to disable the timer synchronously on SMP systems
86 * without calling del_timer_sync(). The latter could cause a
87 * deadlock if called while we're holding spinlocks...
88 */
89static void rpc_run_timer(struct rpc_task *task)
90{
91 void (*callback)(struct rpc_task *);
92
93 callback = task->tk_timeout_fn;
94 task->tk_timeout_fn = NULL;
95 if (callback && RPC_IS_QUEUED(task)) {
Chuck Lever46121cf2007-01-31 12:14:08 -050096 dprintk("RPC: %5u running timer\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 callback(task);
98 }
99 smp_mb__before_clear_bit();
100 clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
101 smp_mb__after_clear_bit();
102}
103
104/*
105 * Set up a timer for the current task.
106 */
107static inline void
108__rpc_add_timer(struct rpc_task *task, rpc_action timer)
109{
110 if (!task->tk_timeout)
111 return;
112
Chuck Lever46121cf2007-01-31 12:14:08 -0500113 dprintk("RPC: %5u setting alarm for %lu ms\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 task->tk_pid, task->tk_timeout * 1000 / HZ);
115
116 if (timer)
117 task->tk_timeout_fn = timer;
118 else
119 task->tk_timeout_fn = __rpc_default_timer;
120 set_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
121 mod_timer(&task->tk_timer, jiffies + task->tk_timeout);
122}
123
124/*
125 * Delete any timer for the current task. Because we use del_timer_sync(),
126 * this function should never be called while holding queue->lock.
127 */
128static void
129rpc_delete_timer(struct rpc_task *task)
130{
131 if (RPC_IS_QUEUED(task))
132 return;
133 if (test_and_clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate)) {
134 del_singleshot_timer_sync(&task->tk_timer);
Chuck Lever46121cf2007-01-31 12:14:08 -0500135 dprintk("RPC: %5u deleting timer\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 }
137}
138
139/*
140 * Add new request to a priority queue.
141 */
142static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct rpc_task *task)
143{
144 struct list_head *q;
145 struct rpc_task *t;
146
147 INIT_LIST_HEAD(&task->u.tk_wait.links);
148 q = &queue->tasks[task->tk_priority];
149 if (unlikely(task->tk_priority > queue->maxpriority))
150 q = &queue->tasks[queue->maxpriority];
151 list_for_each_entry(t, q, u.tk_wait.list) {
152 if (t->tk_cookie == task->tk_cookie) {
153 list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
154 return;
155 }
156 }
157 list_add_tail(&task->u.tk_wait.list, q);
158}
159
160/*
161 * Add new request to wait queue.
162 *
163 * Swapper tasks always get inserted at the head of the queue.
164 * This should avoid many nasty memory deadlocks and hopefully
165 * improve overall performance.
166 * Everyone else gets appended to the queue to ensure proper FIFO behavior.
167 */
168static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
169{
170 BUG_ON (RPC_IS_QUEUED(task));
171
172 if (RPC_IS_PRIORITY(queue))
173 __rpc_add_wait_queue_priority(queue, task);
174 else if (RPC_IS_SWAPPER(task))
175 list_add(&task->u.tk_wait.list, &queue->tasks[0]);
176 else
177 list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
178 task->u.tk_wait.rpc_waitq = queue;
Chuck Levere19b63d2006-03-20 13:44:15 -0500179 queue->qlen++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 rpc_set_queued(task);
181
Chuck Lever46121cf2007-01-31 12:14:08 -0500182 dprintk("RPC: %5u added to queue %p \"%s\"\n",
183 task->tk_pid, queue, rpc_qname(queue));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184}
185
186/*
187 * Remove request from a priority queue.
188 */
189static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
190{
191 struct rpc_task *t;
192
193 if (!list_empty(&task->u.tk_wait.links)) {
194 t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list);
195 list_move(&t->u.tk_wait.list, &task->u.tk_wait.list);
196 list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links);
197 }
198 list_del(&task->u.tk_wait.list);
199}
200
201/*
202 * Remove request from queue.
203 * Note: must be called with spin lock held.
204 */
205static void __rpc_remove_wait_queue(struct rpc_task *task)
206{
207 struct rpc_wait_queue *queue;
208 queue = task->u.tk_wait.rpc_waitq;
209
210 if (RPC_IS_PRIORITY(queue))
211 __rpc_remove_wait_queue_priority(task);
212 else
213 list_del(&task->u.tk_wait.list);
Chuck Levere19b63d2006-03-20 13:44:15 -0500214 queue->qlen--;
Chuck Lever46121cf2007-01-31 12:14:08 -0500215 dprintk("RPC: %5u removed from queue %p \"%s\"\n",
216 task->tk_pid, queue, rpc_qname(queue));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
219static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
220{
221 queue->priority = priority;
222 queue->count = 1 << (priority * 2);
223}
224
225static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie)
226{
227 queue->cookie = cookie;
228 queue->nr = RPC_BATCH_COUNT;
229}
230
231static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
232{
233 rpc_set_waitqueue_priority(queue, queue->maxpriority);
234 rpc_set_waitqueue_cookie(queue, 0);
235}
236
237static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio)
238{
239 int i;
240
241 spin_lock_init(&queue->lock);
242 for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
243 INIT_LIST_HEAD(&queue->tasks[i]);
244 queue->maxpriority = maxprio;
245 rpc_reset_waitqueue_priority(queue);
246#ifdef RPC_DEBUG
247 queue->name = qname;
248#endif
249}
250
251void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
252{
253 __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH);
254}
255
256void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
257{
258 __rpc_init_priority_wait_queue(queue, qname, 0);
259}
260EXPORT_SYMBOL(rpc_init_wait_queue);
261
Trond Myklebust44c28872006-01-03 09:55:06 +0100262static int rpc_wait_bit_interruptible(void *word)
263{
264 if (signal_pending(current))
265 return -ERESTARTSYS;
266 schedule();
267 return 0;
268}
269
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500270static void rpc_set_active(struct rpc_task *task)
271{
272 if (test_and_set_bit(RPC_TASK_ACTIVE, &task->tk_runstate) != 0)
273 return;
274 spin_lock(&rpc_sched_lock);
275#ifdef RPC_DEBUG
276 task->tk_magic = RPC_TASK_MAGIC_ID;
277 task->tk_pid = rpc_task_id++;
278#endif
279 /* Add to global list of all tasks */
280 list_add_tail(&task->tk_task, &all_tasks);
281 spin_unlock(&rpc_sched_lock);
282}
283
Trond Myklebust44c28872006-01-03 09:55:06 +0100284/*
285 * Mark an RPC call as having completed by clearing the 'active' bit
286 */
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500287static void rpc_mark_complete_task(struct rpc_task *task)
Trond Myklebust44c28872006-01-03 09:55:06 +0100288{
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500289 smp_mb__before_clear_bit();
290 clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate);
291 smp_mb__after_clear_bit();
Trond Myklebust44c28872006-01-03 09:55:06 +0100292 wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE);
293}
294
295/*
296 * Allow callers to wait for completion of an RPC call
297 */
298int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *))
299{
300 if (action == NULL)
301 action = rpc_wait_bit_interruptible;
302 return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE,
303 action, TASK_INTERRUPTIBLE);
304}
305EXPORT_SYMBOL(__rpc_wait_for_completion_task);
306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307/*
308 * Make an RPC task runnable.
309 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800310 * Note: If the task is ASYNC, this must be called with
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 * the spinlock held to protect the wait queue operation.
312 */
313static void rpc_make_runnable(struct rpc_task *task)
314{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 BUG_ON(task->tk_timeout_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 rpc_clear_queued(task);
Christophe Saoutcc4dc59e2006-11-05 18:42:48 +0100317 if (rpc_test_and_set_running(task))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 return;
Christophe Saoutcc4dc59e2006-11-05 18:42:48 +0100319 /* We might have raced */
320 if (RPC_IS_QUEUED(task)) {
321 rpc_clear_running(task);
322 return;
323 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 if (RPC_IS_ASYNC(task)) {
325 int status;
326
David Howells65f27f32006-11-22 14:55:48 +0000327 INIT_WORK(&task->u.tk_work, rpc_async_schedule);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 status = queue_work(task->tk_workqueue, &task->u.tk_work);
329 if (status < 0) {
330 printk(KERN_WARNING "RPC: failed to add task to queue: error: %d!\n", status);
331 task->tk_status = status;
332 return;
333 }
334 } else
Trond Myklebust96651ab2005-06-22 17:16:21 +0000335 wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336}
337
338/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 * Prepare for sleeping on a wait queue.
340 * By always appending tasks to the list we ensure FIFO behavior.
341 * NB: An RPC task will only receive interrupt-driven events as long
342 * as it's on a wait queue.
343 */
344static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
345 rpc_action action, rpc_action timer)
346{
Chuck Lever46121cf2007-01-31 12:14:08 -0500347 dprintk("RPC: %5u sleep_on(queue \"%s\" time %lu)\n",
348 task->tk_pid, rpc_qname(q), jiffies);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
350 if (!RPC_IS_ASYNC(task) && !RPC_IS_ACTIVATED(task)) {
351 printk(KERN_ERR "RPC: Inactive synchronous task put to sleep!\n");
352 return;
353 }
354
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 __rpc_add_wait_queue(q, task);
356
357 BUG_ON(task->tk_callback != NULL);
358 task->tk_callback = action;
359 __rpc_add_timer(task, timer);
360}
361
362void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
363 rpc_action action, rpc_action timer)
364{
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500365 /* Mark the task as being activated if so needed */
366 rpc_set_active(task);
367
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 /*
369 * Protect the queue operations.
370 */
371 spin_lock_bh(&q->lock);
372 __rpc_sleep_on(q, task, action, timer);
373 spin_unlock_bh(&q->lock);
374}
375
376/**
377 * __rpc_do_wake_up_task - wake up a single rpc_task
378 * @task: task to be woken up
379 *
380 * Caller must hold queue->lock, and have cleared the task queued flag.
381 */
382static void __rpc_do_wake_up_task(struct rpc_task *task)
383{
Chuck Lever46121cf2007-01-31 12:14:08 -0500384 dprintk("RPC: %5u __rpc_wake_up_task (now %lu)\n",
385 task->tk_pid, jiffies);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387#ifdef RPC_DEBUG
388 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
389#endif
390 /* Has the task been executed yet? If not, we cannot wake it up! */
391 if (!RPC_IS_ACTIVATED(task)) {
392 printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task);
393 return;
394 }
395
396 __rpc_disable_timer(task);
397 __rpc_remove_wait_queue(task);
398
399 rpc_make_runnable(task);
400
Chuck Lever46121cf2007-01-31 12:14:08 -0500401 dprintk("RPC: __rpc_wake_up_task done\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402}
403
404/*
405 * Wake up the specified task
406 */
407static void __rpc_wake_up_task(struct rpc_task *task)
408{
409 if (rpc_start_wakeup(task)) {
410 if (RPC_IS_QUEUED(task))
411 __rpc_do_wake_up_task(task);
412 rpc_finish_wakeup(task);
413 }
414}
415
416/*
417 * Default timeout handler if none specified by user
418 */
419static void
420__rpc_default_timer(struct rpc_task *task)
421{
Chuck Lever46121cf2007-01-31 12:14:08 -0500422 dprintk("RPC: %5u timeout (default timer)\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 task->tk_status = -ETIMEDOUT;
424 rpc_wake_up_task(task);
425}
426
427/*
428 * Wake up the specified task
429 */
430void rpc_wake_up_task(struct rpc_task *task)
431{
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500432 rcu_read_lock_bh();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 if (rpc_start_wakeup(task)) {
434 if (RPC_IS_QUEUED(task)) {
435 struct rpc_wait_queue *queue = task->u.tk_wait.rpc_waitq;
436
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500437 /* Note: we're already in a bh-safe context */
438 spin_lock(&queue->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 __rpc_do_wake_up_task(task);
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500440 spin_unlock(&queue->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 }
442 rpc_finish_wakeup(task);
443 }
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500444 rcu_read_unlock_bh();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445}
446
447/*
448 * Wake up the next task on a priority queue.
449 */
450static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue)
451{
452 struct list_head *q;
453 struct rpc_task *task;
454
455 /*
456 * Service a batch of tasks from a single cookie.
457 */
458 q = &queue->tasks[queue->priority];
459 if (!list_empty(q)) {
460 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
461 if (queue->cookie == task->tk_cookie) {
462 if (--queue->nr)
463 goto out;
464 list_move_tail(&task->u.tk_wait.list, q);
465 }
466 /*
467 * Check if we need to switch queues.
468 */
469 if (--queue->count)
470 goto new_cookie;
471 }
472
473 /*
474 * Service the next queue.
475 */
476 do {
477 if (q == &queue->tasks[0])
478 q = &queue->tasks[queue->maxpriority];
479 else
480 q = q - 1;
481 if (!list_empty(q)) {
482 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
483 goto new_queue;
484 }
485 } while (q != &queue->tasks[queue->priority]);
486
487 rpc_reset_waitqueue_priority(queue);
488 return NULL;
489
490new_queue:
491 rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
492new_cookie:
493 rpc_set_waitqueue_cookie(queue, task->tk_cookie);
494out:
495 __rpc_wake_up_task(task);
496 return task;
497}
498
499/*
500 * Wake up the next task on the wait queue.
501 */
502struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)
503{
504 struct rpc_task *task = NULL;
505
Chuck Lever46121cf2007-01-31 12:14:08 -0500506 dprintk("RPC: wake_up_next(%p \"%s\")\n",
507 queue, rpc_qname(queue));
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500508 rcu_read_lock_bh();
509 spin_lock(&queue->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 if (RPC_IS_PRIORITY(queue))
511 task = __rpc_wake_up_next_priority(queue);
512 else {
513 task_for_first(task, &queue->tasks[0])
514 __rpc_wake_up_task(task);
515 }
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500516 spin_unlock(&queue->lock);
517 rcu_read_unlock_bh();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518
519 return task;
520}
521
522/**
523 * rpc_wake_up - wake up all rpc_tasks
524 * @queue: rpc_wait_queue on which the tasks are sleeping
525 *
526 * Grabs queue->lock
527 */
528void rpc_wake_up(struct rpc_wait_queue *queue)
529{
Trond Myklebuste6d83d52006-03-13 21:20:48 -0800530 struct rpc_task *task, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 struct list_head *head;
Trond Myklebuste6d83d52006-03-13 21:20:48 -0800532
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500533 rcu_read_lock_bh();
534 spin_lock(&queue->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 head = &queue->tasks[queue->maxpriority];
536 for (;;) {
Trond Myklebuste6d83d52006-03-13 21:20:48 -0800537 list_for_each_entry_safe(task, next, head, u.tk_wait.list)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 __rpc_wake_up_task(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 if (head == &queue->tasks[0])
540 break;
541 head--;
542 }
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500543 spin_unlock(&queue->lock);
544 rcu_read_unlock_bh();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545}
546
547/**
548 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
549 * @queue: rpc_wait_queue on which the tasks are sleeping
550 * @status: status value to set
551 *
552 * Grabs queue->lock
553 */
554void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
555{
Trond Myklebuste6d83d52006-03-13 21:20:48 -0800556 struct rpc_task *task, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 struct list_head *head;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500559 rcu_read_lock_bh();
560 spin_lock(&queue->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 head = &queue->tasks[queue->maxpriority];
562 for (;;) {
Trond Myklebuste6d83d52006-03-13 21:20:48 -0800563 list_for_each_entry_safe(task, next, head, u.tk_wait.list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 task->tk_status = status;
565 __rpc_wake_up_task(task);
566 }
567 if (head == &queue->tasks[0])
568 break;
569 head--;
570 }
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500571 spin_unlock(&queue->lock);
572 rcu_read_unlock_bh();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573}
574
Trond Myklebust80147932006-08-31 18:24:08 -0400575static void __rpc_atrun(struct rpc_task *task)
576{
577 rpc_wake_up_task(task);
578}
579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580/*
581 * Run a task at a later time
582 */
Trond Myklebust80147932006-08-31 18:24:08 -0400583void rpc_delay(struct rpc_task *task, unsigned long delay)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584{
585 task->tk_timeout = delay;
586 rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun);
587}
588
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589/*
Trond Myklebust4ce70ad2006-01-03 09:55:05 +0100590 * Helper to call task->tk_ops->rpc_call_prepare
591 */
592static void rpc_prepare_task(struct rpc_task *task)
593{
Trond Myklebust6d5fcb52006-10-18 16:01:06 -0400594 lock_kernel();
Trond Myklebust4ce70ad2006-01-03 09:55:05 +0100595 task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
Trond Myklebust6d5fcb52006-10-18 16:01:06 -0400596 unlock_kernel();
Trond Myklebust4ce70ad2006-01-03 09:55:05 +0100597}
598
599/*
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100600 * Helper that calls task->tk_ops->rpc_call_done if it exists
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000601 */
Trond Myklebustabbcf282006-01-03 09:55:03 +0100602void rpc_exit_task(struct rpc_task *task)
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000603{
Trond Myklebustabbcf282006-01-03 09:55:03 +0100604 task->tk_action = NULL;
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100605 if (task->tk_ops->rpc_call_done != NULL) {
Trond Myklebust6d5fcb52006-10-18 16:01:06 -0400606 lock_kernel();
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100607 task->tk_ops->rpc_call_done(task, task->tk_calldata);
Trond Myklebust6d5fcb52006-10-18 16:01:06 -0400608 unlock_kernel();
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000609 if (task->tk_action != NULL) {
Trond Myklebustabbcf282006-01-03 09:55:03 +0100610 WARN_ON(RPC_ASSASSINATED(task));
611 /* Always release the RPC slot and buffer memory */
612 xprt_release(task);
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000613 }
614 }
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000615}
Trond Myklebustabbcf282006-01-03 09:55:03 +0100616EXPORT_SYMBOL(rpc_exit_task);
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000617
Trond Myklebustbbd5a1f2006-10-18 16:01:05 -0400618void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata)
619{
620 if (ops->rpc_release != NULL) {
621 lock_kernel();
622 ops->rpc_release(calldata);
623 unlock_kernel();
624 }
625}
626
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000627/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 * This is the RPC `scheduler' (or rather, the finite state machine).
629 */
Trond Myklebust2efef832007-02-03 13:38:41 -0800630static void __rpc_execute(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631{
632 int status = 0;
633
Chuck Lever46121cf2007-01-31 12:14:08 -0500634 dprintk("RPC: %5u __rpc_execute flags=0x%x\n",
635 task->tk_pid, task->tk_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
637 BUG_ON(RPC_IS_QUEUED(task));
638
Trond Myklebustd05fdb02005-06-22 17:16:19 +0000639 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 /*
641 * Garbage collection of pending timers...
642 */
643 rpc_delete_timer(task);
644
645 /*
646 * Execute any pending callback.
647 */
648 if (RPC_DO_CALLBACK(task)) {
649 /* Define a callback save pointer */
650 void (*save_callback)(struct rpc_task *);
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800651
652 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 * If a callback exists, save it, reset it,
654 * call it.
655 * The save is needed to stop from resetting
656 * another callback set within the callback handler
657 * - Dave
658 */
659 save_callback=task->tk_callback;
660 task->tk_callback=NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 save_callback(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 }
663
664 /*
665 * Perform the next FSM step.
666 * tk_action may be NULL when the task has been killed
667 * by someone else.
668 */
669 if (!RPC_IS_QUEUED(task)) {
Trond Myklebustabbcf282006-01-03 09:55:03 +0100670 if (task->tk_action == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 break;
Trond Myklebustabbcf282006-01-03 09:55:03 +0100672 task->tk_action(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 }
674
675 /*
676 * Lockless check for whether task is sleeping or not.
677 */
678 if (!RPC_IS_QUEUED(task))
679 continue;
680 rpc_clear_running(task);
681 if (RPC_IS_ASYNC(task)) {
682 /* Careful! we may have raced... */
683 if (RPC_IS_QUEUED(task))
Trond Myklebust2efef832007-02-03 13:38:41 -0800684 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 if (rpc_test_and_set_running(task))
Trond Myklebust2efef832007-02-03 13:38:41 -0800686 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 continue;
688 }
689
690 /* sync task: sleep here */
Chuck Lever46121cf2007-01-31 12:14:08 -0500691 dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid);
Trond Myklebust96651ab2005-06-22 17:16:21 +0000692 /* Note: Caller should be using rpc_clnt_sigmask() */
693 status = out_of_line_wait_on_bit(&task->tk_runstate,
694 RPC_TASK_QUEUED, rpc_wait_bit_interruptible,
695 TASK_INTERRUPTIBLE);
696 if (status == -ERESTARTSYS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 /*
698 * When a sync task receives a signal, it exits with
699 * -ERESTARTSYS. In order to catch any callbacks that
700 * clean up after sleeping on some queue, we don't
701 * break the loop here, but go around once more.
702 */
Chuck Lever46121cf2007-01-31 12:14:08 -0500703 dprintk("RPC: %5u got signal\n", task->tk_pid);
Trond Myklebust96651ab2005-06-22 17:16:21 +0000704 task->tk_flags |= RPC_TASK_KILLED;
705 rpc_exit(task, -ERESTARTSYS);
706 rpc_wake_up_task(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 }
708 rpc_set_running(task);
Chuck Lever46121cf2007-01-31 12:14:08 -0500709 dprintk("RPC: %5u sync task resuming\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 }
711
Chuck Lever46121cf2007-01-31 12:14:08 -0500712 dprintk("RPC: %5u return %d, status %d\n", task->tk_pid, status,
713 task->tk_status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 /* Release all resources associated with the task */
715 rpc_release_task(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716}
717
718/*
719 * User-visible entry point to the scheduler.
720 *
721 * This may be called recursively if e.g. an async NFS task updates
722 * the attributes and finds that dirty pages must be flushed.
723 * NOTE: Upon exit of this function the task is guaranteed to be
724 * released. In particular note that tk_release() will have
725 * been called, so your task memory may have been freed.
726 */
Trond Myklebust2efef832007-02-03 13:38:41 -0800727void rpc_execute(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728{
Trond Myklebust44c28872006-01-03 09:55:06 +0100729 rpc_set_active(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 rpc_set_running(task);
Trond Myklebust2efef832007-02-03 13:38:41 -0800731 __rpc_execute(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732}
733
David Howells65f27f32006-11-22 14:55:48 +0000734static void rpc_async_schedule(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735{
David Howells65f27f32006-11-22 14:55:48 +0000736 __rpc_execute(container_of(work, struct rpc_task, u.tk_work));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737}
738
Chuck Lever02107142006-01-03 09:55:49 +0100739/**
740 * rpc_malloc - allocate an RPC buffer
741 * @task: RPC task that will use this buffer
742 * @size: requested byte size
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 *
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400744 * To prevent rpciod from hanging, this allocator never sleeps,
745 * returning NULL if the request cannot be serviced immediately.
746 * The caller can arrange to sleep in a way that is safe for rpciod.
747 *
748 * Most requests are 'small' (under 2KiB) and can be serviced from a
749 * mempool, ensuring that NFS reads and writes can always proceed,
750 * and that there is good locality of reference for these buffers.
751 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 * In order to avoid memory starvation triggering more writebacks of
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400753 * NFS requests, we avoid using GFP_KERNEL.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 */
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400755void *rpc_malloc(struct rpc_task *task, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756{
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400757 size_t *buf;
758 gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400760 size += sizeof(size_t);
761 if (size <= RPC_BUFFER_MAXSIZE)
762 buf = mempool_alloc(rpc_buffer_mempool, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 else
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400764 buf = kmalloc(size, gfp);
765 *buf = size;
Geert Uytterhoeven215d0672007-05-08 11:37:26 +0200766 dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400767 task->tk_pid, size, buf);
Geert Uytterhoeven215d0672007-05-08 11:37:26 +0200768 return ++buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769}
770
Chuck Lever02107142006-01-03 09:55:49 +0100771/**
772 * rpc_free - free buffer allocated via rpc_malloc
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400773 * @buffer: buffer to free
Chuck Lever02107142006-01-03 09:55:49 +0100774 *
775 */
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400776void rpc_free(void *buffer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777{
Geert Uytterhoeven215d0672007-05-08 11:37:26 +0200778 size_t size, *buf = buffer;
Chuck Lever02107142006-01-03 09:55:49 +0100779
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400780 if (!buffer)
781 return;
782 size = *buf;
783 buf--;
784
Geert Uytterhoeven215d0672007-05-08 11:37:26 +0200785 dprintk("RPC: freeing buffer of size %zu at %p\n",
Chuck Leverc5a4dd82007-03-29 16:47:58 -0400786 size, buf);
787 if (size <= RPC_BUFFER_MAXSIZE)
788 mempool_free(buf, rpc_buffer_mempool);
789 else
790 kfree(buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791}
792
793/*
794 * Creation and deletion of RPC task structures
795 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100796void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797{
798 memset(task, 0, sizeof(*task));
799 init_timer(&task->tk_timer);
800 task->tk_timer.data = (unsigned long) task;
801 task->tk_timer.function = (void (*)(unsigned long)) rpc_run_timer;
Trond Myklebust44c28872006-01-03 09:55:06 +0100802 atomic_set(&task->tk_count, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 task->tk_client = clnt;
804 task->tk_flags = flags;
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100805 task->tk_ops = tk_ops;
Trond Myklebust4ce70ad2006-01-03 09:55:05 +0100806 if (tk_ops->rpc_call_prepare != NULL)
807 task->tk_action = rpc_prepare_task;
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100808 task->tk_calldata = calldata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809
810 /* Initialize retry counters */
811 task->tk_garb_retry = 2;
812 task->tk_cred_retry = 2;
813
814 task->tk_priority = RPC_PRIORITY_NORMAL;
815 task->tk_cookie = (unsigned long)current;
816
817 /* Initialize workqueue for async tasks */
818 task->tk_workqueue = rpciod_workqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819
820 if (clnt) {
821 atomic_inc(&clnt->cl_users);
822 if (clnt->cl_softrtry)
823 task->tk_flags |= RPC_TASK_SOFT;
824 if (!clnt->cl_intr)
825 task->tk_flags |= RPC_TASK_NOINTR;
826 }
827
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100828 BUG_ON(task->tk_ops == NULL);
829
Chuck Leveref759a22006-03-20 13:44:17 -0500830 /* starting timestamp */
831 task->tk_start = jiffies;
832
Chuck Lever46121cf2007-01-31 12:14:08 -0500833 dprintk("RPC: new task initialized, procpid %u\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 current->pid);
835}
836
837static struct rpc_task *
838rpc_alloc_task(void)
839{
840 return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
841}
842
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500843static void rpc_free_task(struct rcu_head *rcu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844{
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500845 struct rpc_task *task = container_of(rcu, struct rpc_task, u.tk_rcu);
Chuck Lever46121cf2007-01-31 12:14:08 -0500846 dprintk("RPC: %5u freeing task\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 mempool_free(task, rpc_task_mempool);
848}
849
850/*
851 * Create a new task for the specified client. We have to
852 * clean up after an allocation failure, as the client may
853 * have specified "oneshot".
854 */
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100855struct rpc_task *rpc_new_task(struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856{
857 struct rpc_task *task;
858
859 task = rpc_alloc_task();
860 if (!task)
861 goto cleanup;
862
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100863 rpc_init_task(task, clnt, flags, tk_ops, calldata);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864
Chuck Lever46121cf2007-01-31 12:14:08 -0500865 dprintk("RPC: allocated task %p\n", task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 task->tk_flags |= RPC_TASK_DYNAMIC;
867out:
868 return task;
869
870cleanup:
871 /* Check whether to release the client */
872 if (clnt) {
873 printk("rpc_new_task: failed, users=%d, oneshot=%d\n",
874 atomic_read(&clnt->cl_users), clnt->cl_oneshot);
875 atomic_inc(&clnt->cl_users); /* pretend we were used ... */
876 rpc_release_client(clnt);
877 }
878 goto out;
879}
880
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500881
882void rpc_put_task(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100884 const struct rpc_call_ops *tk_ops = task->tk_ops;
885 void *calldata = task->tk_calldata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500887 if (!atomic_dec_and_test(&task->tk_count))
888 return;
889 /* Release resources */
890 if (task->tk_rqstp)
891 xprt_release(task);
892 if (task->tk_msg.rpc_cred)
893 rpcauth_unbindcred(task);
894 if (task->tk_client) {
895 rpc_release_client(task->tk_client);
896 task->tk_client = NULL;
897 }
898 if (task->tk_flags & RPC_TASK_DYNAMIC)
Trond Myklebust8aca67f2006-11-13 16:23:44 -0500899 call_rcu_bh(&task->u.tk_rcu, rpc_free_task);
Trond Myklebustbbd5a1f2006-10-18 16:01:05 -0400900 rpc_release_calldata(tk_ops, calldata);
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500901}
902EXPORT_SYMBOL(rpc_put_task);
903
Trond Myklebustbde8f002007-01-24 11:54:53 -0800904static void rpc_release_task(struct rpc_task *task)
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500905{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906#ifdef RPC_DEBUG
907 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
908#endif
Chuck Lever46121cf2007-01-31 12:14:08 -0500909 dprintk("RPC: %5u release task\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
911 /* Remove from global task list */
912 spin_lock(&rpc_sched_lock);
913 list_del(&task->tk_task);
914 spin_unlock(&rpc_sched_lock);
915
916 BUG_ON (RPC_IS_QUEUED(task));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917
918 /* Synchronously delete any running timer */
919 rpc_delete_timer(task);
920
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921#ifdef RPC_DEBUG
922 task->tk_magic = 0;
923#endif
Trond Myklebuste6b3c4d2006-11-11 22:18:03 -0500924 /* Wake up anyone who is waiting for task completion */
925 rpc_mark_complete_task(task);
926
927 rpc_put_task(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928}
929
930/**
Trond Myklebust44c28872006-01-03 09:55:06 +0100931 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
Martin Waitz99acf042006-02-01 03:06:56 -0800932 * @clnt: pointer to RPC client
933 * @flags: RPC flags
934 * @ops: RPC call ops
935 * @data: user call data
Trond Myklebust44c28872006-01-03 09:55:06 +0100936 */
937struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
938 const struct rpc_call_ops *ops,
939 void *data)
940{
941 struct rpc_task *task;
942 task = rpc_new_task(clnt, flags, ops, data);
Trond Myklebust7a1218a2006-03-20 18:11:10 -0500943 if (task == NULL) {
Trond Myklebustbbd5a1f2006-10-18 16:01:05 -0400944 rpc_release_calldata(ops, data);
Trond Myklebust44c28872006-01-03 09:55:06 +0100945 return ERR_PTR(-ENOMEM);
Trond Myklebust7a1218a2006-03-20 18:11:10 -0500946 }
Trond Myklebust44c28872006-01-03 09:55:06 +0100947 atomic_inc(&task->tk_count);
948 rpc_execute(task);
949 return task;
950}
951EXPORT_SYMBOL(rpc_run_task);
952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953/*
954 * Kill all tasks for the given client.
955 * XXX: kill their descendants as well?
956 */
957void rpc_killall_tasks(struct rpc_clnt *clnt)
958{
959 struct rpc_task *rovr;
960 struct list_head *le;
961
Chuck Lever46121cf2007-01-31 12:14:08 -0500962 dprintk("RPC: killing all tasks for client %p\n", clnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963
964 /*
965 * Spin lock all_tasks to prevent changes...
966 */
967 spin_lock(&rpc_sched_lock);
968 alltask_for_each(rovr, le, &all_tasks) {
969 if (! RPC_IS_ACTIVATED(rovr))
970 continue;
971 if (!clnt || rovr->tk_client == clnt) {
972 rovr->tk_flags |= RPC_TASK_KILLED;
973 rpc_exit(rovr, -EIO);
974 rpc_wake_up_task(rovr);
975 }
976 }
977 spin_unlock(&rpc_sched_lock);
978}
979
980static DECLARE_MUTEX_LOCKED(rpciod_running);
981
982static void rpciod_killall(void)
983{
984 unsigned long flags;
985
986 while (!list_empty(&all_tasks)) {
987 clear_thread_flag(TIF_SIGPENDING);
988 rpc_killall_tasks(NULL);
989 flush_workqueue(rpciod_workqueue);
990 if (!list_empty(&all_tasks)) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500991 dprintk("RPC: rpciod_killall: waiting for tasks "
992 "to exit\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 yield();
994 }
995 }
996
997 spin_lock_irqsave(&current->sighand->siglock, flags);
998 recalc_sigpending();
999 spin_unlock_irqrestore(&current->sighand->siglock, flags);
1000}
1001
1002/*
1003 * Start up the rpciod process if it's not already running.
1004 */
1005int
1006rpciod_up(void)
1007{
1008 struct workqueue_struct *wq;
1009 int error = 0;
1010
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -08001011 mutex_lock(&rpciod_mutex);
Chuck Lever46121cf2007-01-31 12:14:08 -05001012 dprintk("RPC: rpciod_up: users %u\n", rpciod_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 rpciod_users++;
1014 if (rpciod_workqueue)
1015 goto out;
1016 /*
1017 * If there's no pid, we should be the first user.
1018 */
1019 if (rpciod_users > 1)
Chuck Lever46121cf2007-01-31 12:14:08 -05001020 printk(KERN_WARNING "rpciod_up: no workqueue, %u users??\n", rpciod_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021 /*
1022 * Create the rpciod thread and wait for it to start.
1023 */
1024 error = -ENOMEM;
1025 wq = create_workqueue("rpciod");
1026 if (wq == NULL) {
1027 printk(KERN_WARNING "rpciod_up: create workqueue failed, error=%d\n", error);
1028 rpciod_users--;
1029 goto out;
1030 }
1031 rpciod_workqueue = wq;
1032 error = 0;
1033out:
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -08001034 mutex_unlock(&rpciod_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 return error;
1036}
1037
1038void
1039rpciod_down(void)
1040{
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -08001041 mutex_lock(&rpciod_mutex);
Chuck Lever46121cf2007-01-31 12:14:08 -05001042 dprintk("RPC: rpciod_down sema %u\n", rpciod_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 if (rpciod_users) {
1044 if (--rpciod_users)
1045 goto out;
1046 } else
1047 printk(KERN_WARNING "rpciod_down: no users??\n");
1048
1049 if (!rpciod_workqueue) {
Chuck Lever46121cf2007-01-31 12:14:08 -05001050 dprintk("RPC: rpciod_down: Nothing to do!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 goto out;
1052 }
1053 rpciod_killall();
1054
1055 destroy_workqueue(rpciod_workqueue);
1056 rpciod_workqueue = NULL;
1057 out:
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -08001058 mutex_unlock(&rpciod_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059}
1060
1061#ifdef RPC_DEBUG
1062void rpc_show_tasks(void)
1063{
1064 struct list_head *le;
1065 struct rpc_task *t;
1066
1067 spin_lock(&rpc_sched_lock);
1068 if (list_empty(&all_tasks)) {
1069 spin_unlock(&rpc_sched_lock);
1070 return;
1071 }
1072 printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
Trond Myklebust963d8fe2006-01-03 09:55:04 +01001073 "-rpcwait -action- ---ops--\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 alltask_for_each(t, le, &all_tasks) {
1075 const char *rpc_waitq = "none";
1076
1077 if (RPC_IS_QUEUED(t))
1078 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1079
Chuck Lever46121cf2007-01-31 12:14:08 -05001080 printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 t->tk_pid,
1082 (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
1083 t->tk_flags, t->tk_status,
1084 t->tk_client,
1085 (t->tk_client ? t->tk_client->cl_prog : 0),
1086 t->tk_rqstp, t->tk_timeout,
1087 rpc_waitq,
Trond Myklebust963d8fe2006-01-03 09:55:04 +01001088 t->tk_action, t->tk_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089 }
1090 spin_unlock(&rpc_sched_lock);
1091}
1092#endif
1093
1094void
1095rpc_destroy_mempool(void)
1096{
1097 if (rpc_buffer_mempool)
1098 mempool_destroy(rpc_buffer_mempool);
1099 if (rpc_task_mempool)
1100 mempool_destroy(rpc_task_mempool);
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -07001101 if (rpc_task_slabp)
1102 kmem_cache_destroy(rpc_task_slabp);
1103 if (rpc_buffer_slabp)
1104 kmem_cache_destroy(rpc_buffer_slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105}
1106
1107int
1108rpc_init_mempool(void)
1109{
1110 rpc_task_slabp = kmem_cache_create("rpc_tasks",
1111 sizeof(struct rpc_task),
1112 0, SLAB_HWCACHE_ALIGN,
1113 NULL, NULL);
1114 if (!rpc_task_slabp)
1115 goto err_nomem;
1116 rpc_buffer_slabp = kmem_cache_create("rpc_buffers",
1117 RPC_BUFFER_MAXSIZE,
1118 0, SLAB_HWCACHE_ALIGN,
1119 NULL, NULL);
1120 if (!rpc_buffer_slabp)
1121 goto err_nomem;
Matthew Dobson93d23412006-03-26 01:37:50 -08001122 rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE,
1123 rpc_task_slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124 if (!rpc_task_mempool)
1125 goto err_nomem;
Matthew Dobson93d23412006-03-26 01:37:50 -08001126 rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE,
1127 rpc_buffer_slabp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 if (!rpc_buffer_mempool)
1129 goto err_nomem;
1130 return 0;
1131err_nomem:
1132 rpc_destroy_mempool();
1133 return -ENOMEM;
1134}