Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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> | |
cca5172a | 7 | * |
1da177e4 LT |
8 | * 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> | |
1da177e4 | 19 | #include <linux/spinlock.h> |
4a3e2f71 | 20 | #include <linux/mutex.h> |
d310310c | 21 | #include <linux/freezer.h> |
1da177e4 LT |
22 | |
23 | #include <linux/sunrpc/clnt.h> | |
1da177e4 | 24 | |
6951867b BH |
25 | #include "sunrpc.h" |
26 | ||
1da177e4 LT |
27 | #ifdef RPC_DEBUG |
28 | #define RPCDBG_FACILITY RPCDBG_SCHED | |
1da177e4 LT |
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) | |
e18b890b CL |
37 | static struct kmem_cache *rpc_task_slabp __read_mostly; |
38 | static struct kmem_cache *rpc_buffer_slabp __read_mostly; | |
ba89966c ED |
39 | static mempool_t *rpc_task_mempool __read_mostly; |
40 | static mempool_t *rpc_buffer_mempool __read_mostly; | |
1da177e4 | 41 | |
65f27f38 | 42 | static void rpc_async_schedule(struct work_struct *); |
bde8f00c | 43 | static void rpc_release_task(struct rpc_task *task); |
36df9aae | 44 | static void __rpc_queue_timer_fn(unsigned long ptr); |
1da177e4 | 45 | |
1da177e4 LT |
46 | /* |
47 | * RPC tasks sit here while waiting for conditions to improve. | |
48 | */ | |
a4a87499 | 49 | static struct rpc_wait_queue delay_queue; |
1da177e4 | 50 | |
1da177e4 LT |
51 | /* |
52 | * rpciod-related stuff | |
53 | */ | |
24c5d9d7 | 54 | struct workqueue_struct *rpciod_workqueue; |
1da177e4 | 55 | |
1da177e4 LT |
56 | /* |
57 | * Disable the timer for a given RPC task. Should be called with | |
58 | * queue->lock and bh_disabled in order to avoid races within | |
59 | * rpc_run_timer(). | |
60 | */ | |
5d00837b | 61 | static void |
eb276c0e | 62 | __rpc_disable_timer(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 63 | { |
36df9aae TM |
64 | if (task->tk_timeout == 0) |
65 | return; | |
46121cf7 | 66 | dprintk("RPC: %5u disabling timer\n", task->tk_pid); |
1da177e4 | 67 | task->tk_timeout = 0; |
36df9aae | 68 | list_del(&task->u.tk_wait.timer_list); |
eb276c0e TM |
69 | if (list_empty(&queue->timer_list.list)) |
70 | del_timer(&queue->timer_list.timer); | |
36df9aae TM |
71 | } |
72 | ||
73 | static void | |
74 | rpc_set_queue_timer(struct rpc_wait_queue *queue, unsigned long expires) | |
75 | { | |
76 | queue->timer_list.expires = expires; | |
77 | mod_timer(&queue->timer_list.timer, expires); | |
1da177e4 LT |
78 | } |
79 | ||
1da177e4 LT |
80 | /* |
81 | * Set up a timer for the current task. | |
82 | */ | |
5d00837b | 83 | static void |
eb276c0e | 84 | __rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 LT |
85 | { |
86 | if (!task->tk_timeout) | |
87 | return; | |
88 | ||
46121cf7 | 89 | dprintk("RPC: %5u setting alarm for %lu ms\n", |
1da177e4 LT |
90 | task->tk_pid, task->tk_timeout * 1000 / HZ); |
91 | ||
eb276c0e TM |
92 | task->u.tk_wait.expires = jiffies + task->tk_timeout; |
93 | if (list_empty(&queue->timer_list.list) || time_before(task->u.tk_wait.expires, queue->timer_list.expires)) | |
94 | rpc_set_queue_timer(queue, task->u.tk_wait.expires); | |
95 | list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list); | |
1da177e4 LT |
96 | } |
97 | ||
98 | /* | |
99 | * Add new request to a priority queue. | |
100 | */ | |
3b27bad7 TM |
101 | static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, |
102 | struct rpc_task *task, | |
103 | unsigned char queue_priority) | |
1da177e4 LT |
104 | { |
105 | struct list_head *q; | |
106 | struct rpc_task *t; | |
107 | ||
108 | INIT_LIST_HEAD(&task->u.tk_wait.links); | |
3b27bad7 TM |
109 | q = &queue->tasks[queue_priority]; |
110 | if (unlikely(queue_priority > queue->maxpriority)) | |
1da177e4 LT |
111 | q = &queue->tasks[queue->maxpriority]; |
112 | list_for_each_entry(t, q, u.tk_wait.list) { | |
3ff7576d | 113 | if (t->tk_owner == task->tk_owner) { |
1da177e4 LT |
114 | list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links); |
115 | return; | |
116 | } | |
117 | } | |
118 | list_add_tail(&task->u.tk_wait.list, q); | |
119 | } | |
120 | ||
121 | /* | |
122 | * Add new request to wait queue. | |
123 | * | |
124 | * Swapper tasks always get inserted at the head of the queue. | |
125 | * This should avoid many nasty memory deadlocks and hopefully | |
126 | * improve overall performance. | |
127 | * Everyone else gets appended to the queue to ensure proper FIFO behavior. | |
128 | */ | |
3b27bad7 TM |
129 | static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, |
130 | struct rpc_task *task, | |
131 | unsigned char queue_priority) | |
1da177e4 LT |
132 | { |
133 | BUG_ON (RPC_IS_QUEUED(task)); | |
134 | ||
135 | if (RPC_IS_PRIORITY(queue)) | |
3b27bad7 | 136 | __rpc_add_wait_queue_priority(queue, task, queue_priority); |
1da177e4 LT |
137 | else if (RPC_IS_SWAPPER(task)) |
138 | list_add(&task->u.tk_wait.list, &queue->tasks[0]); | |
139 | else | |
140 | list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]); | |
96ef13b2 | 141 | task->tk_waitqueue = queue; |
e19b63da | 142 | queue->qlen++; |
1da177e4 LT |
143 | rpc_set_queued(task); |
144 | ||
46121cf7 CL |
145 | dprintk("RPC: %5u added to queue %p \"%s\"\n", |
146 | task->tk_pid, queue, rpc_qname(queue)); | |
1da177e4 LT |
147 | } |
148 | ||
149 | /* | |
150 | * Remove request from a priority queue. | |
151 | */ | |
152 | static void __rpc_remove_wait_queue_priority(struct rpc_task *task) | |
153 | { | |
154 | struct rpc_task *t; | |
155 | ||
156 | if (!list_empty(&task->u.tk_wait.links)) { | |
157 | t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list); | |
158 | list_move(&t->u.tk_wait.list, &task->u.tk_wait.list); | |
159 | list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links); | |
160 | } | |
1da177e4 LT |
161 | } |
162 | ||
163 | /* | |
164 | * Remove request from queue. | |
165 | * Note: must be called with spin lock held. | |
166 | */ | |
96ef13b2 | 167 | static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 168 | { |
eb276c0e | 169 | __rpc_disable_timer(queue, task); |
1da177e4 LT |
170 | if (RPC_IS_PRIORITY(queue)) |
171 | __rpc_remove_wait_queue_priority(task); | |
36df9aae | 172 | list_del(&task->u.tk_wait.list); |
e19b63da | 173 | queue->qlen--; |
46121cf7 CL |
174 | dprintk("RPC: %5u removed from queue %p \"%s\"\n", |
175 | task->tk_pid, queue, rpc_qname(queue)); | |
1da177e4 LT |
176 | } |
177 | ||
178 | static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority) | |
179 | { | |
180 | queue->priority = priority; | |
181 | queue->count = 1 << (priority * 2); | |
182 | } | |
183 | ||
3ff7576d | 184 | static inline void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid) |
1da177e4 | 185 | { |
3ff7576d | 186 | queue->owner = pid; |
1da177e4 LT |
187 | queue->nr = RPC_BATCH_COUNT; |
188 | } | |
189 | ||
190 | static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue) | |
191 | { | |
192 | rpc_set_waitqueue_priority(queue, queue->maxpriority); | |
3ff7576d | 193 | rpc_set_waitqueue_owner(queue, 0); |
1da177e4 LT |
194 | } |
195 | ||
3ff7576d | 196 | static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues) |
1da177e4 LT |
197 | { |
198 | int i; | |
199 | ||
200 | spin_lock_init(&queue->lock); | |
201 | for (i = 0; i < ARRAY_SIZE(queue->tasks); i++) | |
202 | INIT_LIST_HEAD(&queue->tasks[i]); | |
3ff7576d | 203 | queue->maxpriority = nr_queues - 1; |
1da177e4 | 204 | rpc_reset_waitqueue_priority(queue); |
36df9aae TM |
205 | queue->qlen = 0; |
206 | setup_timer(&queue->timer_list.timer, __rpc_queue_timer_fn, (unsigned long)queue); | |
207 | INIT_LIST_HEAD(&queue->timer_list.list); | |
1da177e4 LT |
208 | #ifdef RPC_DEBUG |
209 | queue->name = qname; | |
210 | #endif | |
211 | } | |
212 | ||
213 | void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
214 | { | |
3ff7576d | 215 | __rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY); |
1da177e4 | 216 | } |
689cf5c1 | 217 | EXPORT_SYMBOL_GPL(rpc_init_priority_wait_queue); |
1da177e4 LT |
218 | |
219 | void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
220 | { | |
3ff7576d | 221 | __rpc_init_priority_wait_queue(queue, qname, 1); |
1da177e4 | 222 | } |
e8914c65 | 223 | EXPORT_SYMBOL_GPL(rpc_init_wait_queue); |
1da177e4 | 224 | |
f6a1cc89 TM |
225 | void rpc_destroy_wait_queue(struct rpc_wait_queue *queue) |
226 | { | |
36df9aae | 227 | del_timer_sync(&queue->timer_list.timer); |
f6a1cc89 TM |
228 | } |
229 | EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue); | |
230 | ||
150030b7 | 231 | static int rpc_wait_bit_killable(void *word) |
44c28873 | 232 | { |
150030b7 | 233 | if (fatal_signal_pending(current)) |
44c28873 | 234 | return -ERESTARTSYS; |
d310310c | 235 | freezable_schedule(); |
44c28873 TM |
236 | return 0; |
237 | } | |
238 | ||
c44fe705 TM |
239 | #ifdef RPC_DEBUG |
240 | static void rpc_task_set_debuginfo(struct rpc_task *task) | |
241 | { | |
242 | static atomic_t rpc_pid; | |
243 | ||
c44fe705 TM |
244 | task->tk_pid = atomic_inc_return(&rpc_pid); |
245 | } | |
246 | #else | |
247 | static inline void rpc_task_set_debuginfo(struct rpc_task *task) | |
248 | { | |
249 | } | |
250 | #endif | |
251 | ||
e6b3c4db TM |
252 | static void rpc_set_active(struct rpc_task *task) |
253 | { | |
c44fe705 | 254 | rpc_task_set_debuginfo(task); |
58f9612c | 255 | set_bit(RPC_TASK_ACTIVE, &task->tk_runstate); |
e6b3c4db TM |
256 | } |
257 | ||
44c28873 TM |
258 | /* |
259 | * Mark an RPC call as having completed by clearing the 'active' bit | |
bf294b41 | 260 | * and then waking up all tasks that were sleeping. |
44c28873 | 261 | */ |
bf294b41 | 262 | static int rpc_complete_task(struct rpc_task *task) |
44c28873 | 263 | { |
bf294b41 TM |
264 | void *m = &task->tk_runstate; |
265 | wait_queue_head_t *wq = bit_waitqueue(m, RPC_TASK_ACTIVE); | |
266 | struct wait_bit_key k = __WAIT_BIT_KEY_INITIALIZER(m, RPC_TASK_ACTIVE); | |
267 | unsigned long flags; | |
268 | int ret; | |
269 | ||
270 | spin_lock_irqsave(&wq->lock, flags); | |
e6b3c4db | 271 | clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate); |
bf294b41 TM |
272 | ret = atomic_dec_and_test(&task->tk_count); |
273 | if (waitqueue_active(wq)) | |
274 | __wake_up_locked_key(wq, TASK_NORMAL, &k); | |
275 | spin_unlock_irqrestore(&wq->lock, flags); | |
276 | return ret; | |
44c28873 TM |
277 | } |
278 | ||
279 | /* | |
280 | * Allow callers to wait for completion of an RPC call | |
bf294b41 TM |
281 | * |
282 | * Note the use of out_of_line_wait_on_bit() rather than wait_on_bit() | |
283 | * to enforce taking of the wq->lock and hence avoid races with | |
284 | * rpc_complete_task(). | |
44c28873 TM |
285 | */ |
286 | int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *)) | |
287 | { | |
288 | if (action == NULL) | |
150030b7 | 289 | action = rpc_wait_bit_killable; |
bf294b41 | 290 | return out_of_line_wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE, |
150030b7 | 291 | action, TASK_KILLABLE); |
44c28873 | 292 | } |
e8914c65 | 293 | EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task); |
44c28873 | 294 | |
1da177e4 LT |
295 | /* |
296 | * Make an RPC task runnable. | |
297 | * | |
cca5172a | 298 | * Note: If the task is ASYNC, this must be called with |
1da177e4 LT |
299 | * the spinlock held to protect the wait queue operation. |
300 | */ | |
301 | static void rpc_make_runnable(struct rpc_task *task) | |
302 | { | |
1da177e4 | 303 | rpc_clear_queued(task); |
cc4dc59e CS |
304 | if (rpc_test_and_set_running(task)) |
305 | return; | |
1da177e4 | 306 | if (RPC_IS_ASYNC(task)) { |
65f27f38 | 307 | INIT_WORK(&task->u.tk_work, rpc_async_schedule); |
cee6a537 | 308 | queue_work(rpciod_workqueue, &task->u.tk_work); |
1da177e4 | 309 | } else |
96651ab3 | 310 | wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED); |
1da177e4 LT |
311 | } |
312 | ||
1da177e4 LT |
313 | /* |
314 | * Prepare for sleeping on a wait queue. | |
315 | * By always appending tasks to the list we ensure FIFO behavior. | |
316 | * NB: An RPC task will only receive interrupt-driven events as long | |
317 | * as it's on a wait queue. | |
318 | */ | |
3b27bad7 TM |
319 | static void __rpc_sleep_on_priority(struct rpc_wait_queue *q, |
320 | struct rpc_task *task, | |
321 | rpc_action action, | |
322 | unsigned char queue_priority) | |
1da177e4 | 323 | { |
46121cf7 CL |
324 | dprintk("RPC: %5u sleep_on(queue \"%s\" time %lu)\n", |
325 | task->tk_pid, rpc_qname(q), jiffies); | |
1da177e4 | 326 | |
3b27bad7 | 327 | __rpc_add_wait_queue(q, task, queue_priority); |
1da177e4 LT |
328 | |
329 | BUG_ON(task->tk_callback != NULL); | |
330 | task->tk_callback = action; | |
eb276c0e | 331 | __rpc_add_timer(q, task); |
1da177e4 LT |
332 | } |
333 | ||
334 | void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task, | |
5d00837b | 335 | rpc_action action) |
1da177e4 | 336 | { |
58f9612c TM |
337 | /* We shouldn't ever put an inactive task to sleep */ |
338 | BUG_ON(!RPC_IS_ACTIVATED(task)); | |
e6b3c4db | 339 | |
1da177e4 LT |
340 | /* |
341 | * Protect the queue operations. | |
342 | */ | |
343 | spin_lock_bh(&q->lock); | |
3b27bad7 | 344 | __rpc_sleep_on_priority(q, task, action, task->tk_priority); |
1da177e4 LT |
345 | spin_unlock_bh(&q->lock); |
346 | } | |
e8914c65 | 347 | EXPORT_SYMBOL_GPL(rpc_sleep_on); |
1da177e4 | 348 | |
3b27bad7 TM |
349 | void rpc_sleep_on_priority(struct rpc_wait_queue *q, struct rpc_task *task, |
350 | rpc_action action, int priority) | |
351 | { | |
352 | /* We shouldn't ever put an inactive task to sleep */ | |
353 | BUG_ON(!RPC_IS_ACTIVATED(task)); | |
354 | ||
355 | /* | |
356 | * Protect the queue operations. | |
357 | */ | |
358 | spin_lock_bh(&q->lock); | |
359 | __rpc_sleep_on_priority(q, task, action, priority - RPC_PRIORITY_LOW); | |
360 | spin_unlock_bh(&q->lock); | |
361 | } | |
362 | ||
1da177e4 LT |
363 | /** |
364 | * __rpc_do_wake_up_task - wake up a single rpc_task | |
96ef13b2 | 365 | * @queue: wait queue |
1da177e4 LT |
366 | * @task: task to be woken up |
367 | * | |
368 | * Caller must hold queue->lock, and have cleared the task queued flag. | |
369 | */ | |
96ef13b2 | 370 | static void __rpc_do_wake_up_task(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 371 | { |
46121cf7 CL |
372 | dprintk("RPC: %5u __rpc_wake_up_task (now %lu)\n", |
373 | task->tk_pid, jiffies); | |
1da177e4 | 374 | |
1da177e4 LT |
375 | /* Has the task been executed yet? If not, we cannot wake it up! */ |
376 | if (!RPC_IS_ACTIVATED(task)) { | |
377 | printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task); | |
378 | return; | |
379 | } | |
380 | ||
96ef13b2 | 381 | __rpc_remove_wait_queue(queue, task); |
1da177e4 LT |
382 | |
383 | rpc_make_runnable(task); | |
384 | ||
46121cf7 | 385 | dprintk("RPC: __rpc_wake_up_task done\n"); |
1da177e4 LT |
386 | } |
387 | ||
388 | /* | |
96ef13b2 | 389 | * Wake up a queued task while the queue lock is being held |
1da177e4 | 390 | */ |
96ef13b2 | 391 | static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 392 | { |
f5fb7b06 TM |
393 | if (RPC_IS_QUEUED(task) && task->tk_waitqueue == queue) |
394 | __rpc_do_wake_up_task(queue, task); | |
1da177e4 LT |
395 | } |
396 | ||
48f18612 AB |
397 | /* |
398 | * Tests whether rpc queue is empty | |
399 | */ | |
400 | int rpc_queue_empty(struct rpc_wait_queue *queue) | |
401 | { | |
402 | int res; | |
403 | ||
404 | spin_lock_bh(&queue->lock); | |
405 | res = queue->qlen; | |
406 | spin_unlock_bh(&queue->lock); | |
a02cec21 | 407 | return res == 0; |
48f18612 AB |
408 | } |
409 | EXPORT_SYMBOL_GPL(rpc_queue_empty); | |
410 | ||
1da177e4 | 411 | /* |
96ef13b2 | 412 | * Wake up a task on a specific queue |
1da177e4 | 413 | */ |
96ef13b2 | 414 | void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 415 | { |
5e4424af | 416 | spin_lock_bh(&queue->lock); |
96ef13b2 | 417 | rpc_wake_up_task_queue_locked(queue, task); |
5e4424af | 418 | spin_unlock_bh(&queue->lock); |
1da177e4 | 419 | } |
96ef13b2 TM |
420 | EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task); |
421 | ||
1da177e4 LT |
422 | /* |
423 | * Wake up the next task on a priority queue. | |
424 | */ | |
961a828d | 425 | static struct rpc_task *__rpc_find_next_queued_priority(struct rpc_wait_queue *queue) |
1da177e4 LT |
426 | { |
427 | struct list_head *q; | |
428 | struct rpc_task *task; | |
429 | ||
430 | /* | |
3ff7576d | 431 | * Service a batch of tasks from a single owner. |
1da177e4 LT |
432 | */ |
433 | q = &queue->tasks[queue->priority]; | |
434 | if (!list_empty(q)) { | |
435 | task = list_entry(q->next, struct rpc_task, u.tk_wait.list); | |
3ff7576d | 436 | if (queue->owner == task->tk_owner) { |
1da177e4 LT |
437 | if (--queue->nr) |
438 | goto out; | |
439 | list_move_tail(&task->u.tk_wait.list, q); | |
440 | } | |
441 | /* | |
442 | * Check if we need to switch queues. | |
443 | */ | |
444 | if (--queue->count) | |
3ff7576d | 445 | goto new_owner; |
1da177e4 LT |
446 | } |
447 | ||
448 | /* | |
449 | * Service the next queue. | |
450 | */ | |
451 | do { | |
452 | if (q == &queue->tasks[0]) | |
453 | q = &queue->tasks[queue->maxpriority]; | |
454 | else | |
455 | q = q - 1; | |
456 | if (!list_empty(q)) { | |
457 | task = list_entry(q->next, struct rpc_task, u.tk_wait.list); | |
458 | goto new_queue; | |
459 | } | |
460 | } while (q != &queue->tasks[queue->priority]); | |
461 | ||
462 | rpc_reset_waitqueue_priority(queue); | |
463 | return NULL; | |
464 | ||
465 | new_queue: | |
466 | rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0])); | |
3ff7576d TM |
467 | new_owner: |
468 | rpc_set_waitqueue_owner(queue, task->tk_owner); | |
1da177e4 | 469 | out: |
1da177e4 LT |
470 | return task; |
471 | } | |
472 | ||
961a828d TM |
473 | static struct rpc_task *__rpc_find_next_queued(struct rpc_wait_queue *queue) |
474 | { | |
475 | if (RPC_IS_PRIORITY(queue)) | |
476 | return __rpc_find_next_queued_priority(queue); | |
477 | if (!list_empty(&queue->tasks[0])) | |
478 | return list_first_entry(&queue->tasks[0], struct rpc_task, u.tk_wait.list); | |
479 | return NULL; | |
480 | } | |
481 | ||
1da177e4 | 482 | /* |
961a828d | 483 | * Wake up the first task on the wait queue. |
1da177e4 | 484 | */ |
961a828d TM |
485 | struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *queue, |
486 | bool (*func)(struct rpc_task *, void *), void *data) | |
1da177e4 LT |
487 | { |
488 | struct rpc_task *task = NULL; | |
489 | ||
961a828d | 490 | dprintk("RPC: wake_up_first(%p \"%s\")\n", |
46121cf7 | 491 | queue, rpc_qname(queue)); |
5e4424af | 492 | spin_lock_bh(&queue->lock); |
961a828d TM |
493 | task = __rpc_find_next_queued(queue); |
494 | if (task != NULL) { | |
495 | if (func(task, data)) | |
96ef13b2 | 496 | rpc_wake_up_task_queue_locked(queue, task); |
961a828d TM |
497 | else |
498 | task = NULL; | |
1da177e4 | 499 | } |
5e4424af | 500 | spin_unlock_bh(&queue->lock); |
1da177e4 LT |
501 | |
502 | return task; | |
503 | } | |
961a828d TM |
504 | EXPORT_SYMBOL_GPL(rpc_wake_up_first); |
505 | ||
506 | static bool rpc_wake_up_next_func(struct rpc_task *task, void *data) | |
507 | { | |
508 | return true; | |
509 | } | |
510 | ||
511 | /* | |
512 | * Wake up the next task on the wait queue. | |
513 | */ | |
514 | struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *queue) | |
515 | { | |
516 | return rpc_wake_up_first(queue, rpc_wake_up_next_func, NULL); | |
517 | } | |
e8914c65 | 518 | EXPORT_SYMBOL_GPL(rpc_wake_up_next); |
1da177e4 LT |
519 | |
520 | /** | |
521 | * rpc_wake_up - wake up all rpc_tasks | |
522 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
523 | * | |
524 | * Grabs queue->lock | |
525 | */ | |
526 | void rpc_wake_up(struct rpc_wait_queue *queue) | |
527 | { | |
e6d83d55 | 528 | struct rpc_task *task, *next; |
1da177e4 | 529 | struct list_head *head; |
e6d83d55 | 530 | |
5e4424af | 531 | spin_lock_bh(&queue->lock); |
1da177e4 LT |
532 | head = &queue->tasks[queue->maxpriority]; |
533 | for (;;) { | |
e6d83d55 | 534 | list_for_each_entry_safe(task, next, head, u.tk_wait.list) |
96ef13b2 | 535 | rpc_wake_up_task_queue_locked(queue, task); |
1da177e4 LT |
536 | if (head == &queue->tasks[0]) |
537 | break; | |
538 | head--; | |
539 | } | |
5e4424af | 540 | spin_unlock_bh(&queue->lock); |
1da177e4 | 541 | } |
e8914c65 | 542 | EXPORT_SYMBOL_GPL(rpc_wake_up); |
1da177e4 LT |
543 | |
544 | /** | |
545 | * rpc_wake_up_status - wake up all rpc_tasks and set their status value. | |
546 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
547 | * @status: status value to set | |
548 | * | |
549 | * Grabs queue->lock | |
550 | */ | |
551 | void rpc_wake_up_status(struct rpc_wait_queue *queue, int status) | |
552 | { | |
e6d83d55 | 553 | struct rpc_task *task, *next; |
1da177e4 | 554 | struct list_head *head; |
1da177e4 | 555 | |
5e4424af | 556 | spin_lock_bh(&queue->lock); |
1da177e4 LT |
557 | head = &queue->tasks[queue->maxpriority]; |
558 | for (;;) { | |
e6d83d55 | 559 | list_for_each_entry_safe(task, next, head, u.tk_wait.list) { |
1da177e4 | 560 | task->tk_status = status; |
96ef13b2 | 561 | rpc_wake_up_task_queue_locked(queue, task); |
1da177e4 LT |
562 | } |
563 | if (head == &queue->tasks[0]) | |
564 | break; | |
565 | head--; | |
566 | } | |
5e4424af | 567 | spin_unlock_bh(&queue->lock); |
1da177e4 | 568 | } |
e8914c65 | 569 | EXPORT_SYMBOL_GPL(rpc_wake_up_status); |
1da177e4 | 570 | |
36df9aae TM |
571 | static void __rpc_queue_timer_fn(unsigned long ptr) |
572 | { | |
573 | struct rpc_wait_queue *queue = (struct rpc_wait_queue *)ptr; | |
574 | struct rpc_task *task, *n; | |
575 | unsigned long expires, now, timeo; | |
576 | ||
577 | spin_lock(&queue->lock); | |
578 | expires = now = jiffies; | |
579 | list_for_each_entry_safe(task, n, &queue->timer_list.list, u.tk_wait.timer_list) { | |
580 | timeo = task->u.tk_wait.expires; | |
581 | if (time_after_eq(now, timeo)) { | |
36df9aae TM |
582 | dprintk("RPC: %5u timeout\n", task->tk_pid); |
583 | task->tk_status = -ETIMEDOUT; | |
584 | rpc_wake_up_task_queue_locked(queue, task); | |
585 | continue; | |
586 | } | |
587 | if (expires == now || time_after(expires, timeo)) | |
588 | expires = timeo; | |
589 | } | |
590 | if (!list_empty(&queue->timer_list.list)) | |
591 | rpc_set_queue_timer(queue, expires); | |
592 | spin_unlock(&queue->lock); | |
593 | } | |
594 | ||
8014793b TM |
595 | static void __rpc_atrun(struct rpc_task *task) |
596 | { | |
5d00837b | 597 | task->tk_status = 0; |
8014793b TM |
598 | } |
599 | ||
1da177e4 LT |
600 | /* |
601 | * Run a task at a later time | |
602 | */ | |
8014793b | 603 | void rpc_delay(struct rpc_task *task, unsigned long delay) |
1da177e4 LT |
604 | { |
605 | task->tk_timeout = delay; | |
5d00837b | 606 | rpc_sleep_on(&delay_queue, task, __rpc_atrun); |
1da177e4 | 607 | } |
e8914c65 | 608 | EXPORT_SYMBOL_GPL(rpc_delay); |
1da177e4 | 609 | |
4ce70ada TM |
610 | /* |
611 | * Helper to call task->tk_ops->rpc_call_prepare | |
612 | */ | |
aae2006e | 613 | void rpc_prepare_task(struct rpc_task *task) |
4ce70ada TM |
614 | { |
615 | task->tk_ops->rpc_call_prepare(task, task->tk_calldata); | |
616 | } | |
617 | ||
7fdcf13b TM |
618 | static void |
619 | rpc_init_task_statistics(struct rpc_task *task) | |
620 | { | |
621 | /* Initialize retry counters */ | |
622 | task->tk_garb_retry = 2; | |
623 | task->tk_cred_retry = 2; | |
624 | task->tk_rebind_retry = 2; | |
625 | ||
626 | /* starting timestamp */ | |
627 | task->tk_start = ktime_get(); | |
628 | } | |
629 | ||
630 | static void | |
631 | rpc_reset_task_statistics(struct rpc_task *task) | |
632 | { | |
633 | task->tk_timeouts = 0; | |
634 | task->tk_flags &= ~(RPC_CALL_MAJORSEEN|RPC_TASK_KILLED|RPC_TASK_SENT); | |
635 | ||
636 | rpc_init_task_statistics(task); | |
637 | } | |
638 | ||
d05fdb0c | 639 | /* |
963d8fe5 | 640 | * Helper that calls task->tk_ops->rpc_call_done if it exists |
d05fdb0c | 641 | */ |
abbcf28f | 642 | void rpc_exit_task(struct rpc_task *task) |
d05fdb0c | 643 | { |
abbcf28f | 644 | task->tk_action = NULL; |
963d8fe5 TM |
645 | if (task->tk_ops->rpc_call_done != NULL) { |
646 | task->tk_ops->rpc_call_done(task, task->tk_calldata); | |
d05fdb0c | 647 | if (task->tk_action != NULL) { |
abbcf28f TM |
648 | WARN_ON(RPC_ASSASSINATED(task)); |
649 | /* Always release the RPC slot and buffer memory */ | |
650 | xprt_release(task); | |
7fdcf13b | 651 | rpc_reset_task_statistics(task); |
d05fdb0c TM |
652 | } |
653 | } | |
d05fdb0c | 654 | } |
d9b6cd94 TM |
655 | |
656 | void rpc_exit(struct rpc_task *task, int status) | |
657 | { | |
658 | task->tk_status = status; | |
659 | task->tk_action = rpc_exit_task; | |
660 | if (RPC_IS_QUEUED(task)) | |
661 | rpc_wake_up_queued_task(task->tk_waitqueue, task); | |
662 | } | |
663 | EXPORT_SYMBOL_GPL(rpc_exit); | |
d05fdb0c | 664 | |
bbd5a1f9 TM |
665 | void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata) |
666 | { | |
a86dc496 | 667 | if (ops->rpc_release != NULL) |
bbd5a1f9 | 668 | ops->rpc_release(calldata); |
bbd5a1f9 TM |
669 | } |
670 | ||
1da177e4 LT |
671 | /* |
672 | * This is the RPC `scheduler' (or rather, the finite state machine). | |
673 | */ | |
2efef837 | 674 | static void __rpc_execute(struct rpc_task *task) |
1da177e4 | 675 | { |
eb9b55ab TM |
676 | struct rpc_wait_queue *queue; |
677 | int task_is_async = RPC_IS_ASYNC(task); | |
678 | int status = 0; | |
1da177e4 | 679 | |
46121cf7 CL |
680 | dprintk("RPC: %5u __rpc_execute flags=0x%x\n", |
681 | task->tk_pid, task->tk_flags); | |
1da177e4 LT |
682 | |
683 | BUG_ON(RPC_IS_QUEUED(task)); | |
684 | ||
d05fdb0c | 685 | for (;;) { |
b55c5989 | 686 | void (*do_action)(struct rpc_task *); |
1da177e4 LT |
687 | |
688 | /* | |
b55c5989 | 689 | * Execute any pending callback first. |
1da177e4 | 690 | */ |
b55c5989 TM |
691 | do_action = task->tk_callback; |
692 | task->tk_callback = NULL; | |
693 | if (do_action == NULL) { | |
e020c680 TM |
694 | /* |
695 | * Perform the next FSM step. | |
b55c5989 TM |
696 | * tk_action may be NULL if the task has been killed. |
697 | * In particular, note that rpc_killall_tasks may | |
698 | * do this at any time, so beware when dereferencing. | |
e020c680 | 699 | */ |
b55c5989 TM |
700 | do_action = task->tk_action; |
701 | if (do_action == NULL) | |
1da177e4 | 702 | break; |
1da177e4 | 703 | } |
b55c5989 | 704 | do_action(task); |
1da177e4 LT |
705 | |
706 | /* | |
707 | * Lockless check for whether task is sleeping or not. | |
708 | */ | |
709 | if (!RPC_IS_QUEUED(task)) | |
710 | continue; | |
eb9b55ab TM |
711 | /* |
712 | * The queue->lock protects against races with | |
713 | * rpc_make_runnable(). | |
714 | * | |
715 | * Note that once we clear RPC_TASK_RUNNING on an asynchronous | |
716 | * rpc_task, rpc_make_runnable() can assign it to a | |
717 | * different workqueue. We therefore cannot assume that the | |
718 | * rpc_task pointer may still be dereferenced. | |
719 | */ | |
720 | queue = task->tk_waitqueue; | |
721 | spin_lock_bh(&queue->lock); | |
722 | if (!RPC_IS_QUEUED(task)) { | |
723 | spin_unlock_bh(&queue->lock); | |
1da177e4 LT |
724 | continue; |
725 | } | |
eb9b55ab TM |
726 | rpc_clear_running(task); |
727 | spin_unlock_bh(&queue->lock); | |
728 | if (task_is_async) | |
729 | return; | |
1da177e4 LT |
730 | |
731 | /* sync task: sleep here */ | |
46121cf7 | 732 | dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid); |
96651ab3 | 733 | status = out_of_line_wait_on_bit(&task->tk_runstate, |
150030b7 MW |
734 | RPC_TASK_QUEUED, rpc_wait_bit_killable, |
735 | TASK_KILLABLE); | |
96651ab3 | 736 | if (status == -ERESTARTSYS) { |
1da177e4 LT |
737 | /* |
738 | * When a sync task receives a signal, it exits with | |
739 | * -ERESTARTSYS. In order to catch any callbacks that | |
740 | * clean up after sleeping on some queue, we don't | |
741 | * break the loop here, but go around once more. | |
742 | */ | |
46121cf7 | 743 | dprintk("RPC: %5u got signal\n", task->tk_pid); |
96651ab3 TM |
744 | task->tk_flags |= RPC_TASK_KILLED; |
745 | rpc_exit(task, -ERESTARTSYS); | |
1da177e4 LT |
746 | } |
747 | rpc_set_running(task); | |
46121cf7 | 748 | dprintk("RPC: %5u sync task resuming\n", task->tk_pid); |
1da177e4 LT |
749 | } |
750 | ||
46121cf7 CL |
751 | dprintk("RPC: %5u return %d, status %d\n", task->tk_pid, status, |
752 | task->tk_status); | |
1da177e4 LT |
753 | /* Release all resources associated with the task */ |
754 | rpc_release_task(task); | |
1da177e4 LT |
755 | } |
756 | ||
757 | /* | |
758 | * User-visible entry point to the scheduler. | |
759 | * | |
760 | * This may be called recursively if e.g. an async NFS task updates | |
761 | * the attributes and finds that dirty pages must be flushed. | |
762 | * NOTE: Upon exit of this function the task is guaranteed to be | |
763 | * released. In particular note that tk_release() will have | |
764 | * been called, so your task memory may have been freed. | |
765 | */ | |
2efef837 | 766 | void rpc_execute(struct rpc_task *task) |
1da177e4 | 767 | { |
44c28873 | 768 | rpc_set_active(task); |
d6a1ed08 TM |
769 | rpc_make_runnable(task); |
770 | if (!RPC_IS_ASYNC(task)) | |
771 | __rpc_execute(task); | |
1da177e4 LT |
772 | } |
773 | ||
65f27f38 | 774 | static void rpc_async_schedule(struct work_struct *work) |
1da177e4 | 775 | { |
65f27f38 | 776 | __rpc_execute(container_of(work, struct rpc_task, u.tk_work)); |
1da177e4 LT |
777 | } |
778 | ||
02107148 CL |
779 | /** |
780 | * rpc_malloc - allocate an RPC buffer | |
781 | * @task: RPC task that will use this buffer | |
782 | * @size: requested byte size | |
1da177e4 | 783 | * |
c5a4dd8b CL |
784 | * To prevent rpciod from hanging, this allocator never sleeps, |
785 | * returning NULL if the request cannot be serviced immediately. | |
786 | * The caller can arrange to sleep in a way that is safe for rpciod. | |
787 | * | |
788 | * Most requests are 'small' (under 2KiB) and can be serviced from a | |
789 | * mempool, ensuring that NFS reads and writes can always proceed, | |
790 | * and that there is good locality of reference for these buffers. | |
791 | * | |
1da177e4 | 792 | * In order to avoid memory starvation triggering more writebacks of |
c5a4dd8b | 793 | * NFS requests, we avoid using GFP_KERNEL. |
1da177e4 | 794 | */ |
c5a4dd8b | 795 | void *rpc_malloc(struct rpc_task *task, size_t size) |
1da177e4 | 796 | { |
aa3d1fae | 797 | struct rpc_buffer *buf; |
c5a4dd8b | 798 | gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT; |
1da177e4 | 799 | |
aa3d1fae | 800 | size += sizeof(struct rpc_buffer); |
c5a4dd8b CL |
801 | if (size <= RPC_BUFFER_MAXSIZE) |
802 | buf = mempool_alloc(rpc_buffer_mempool, gfp); | |
1da177e4 | 803 | else |
c5a4dd8b | 804 | buf = kmalloc(size, gfp); |
ddce40df PZ |
805 | |
806 | if (!buf) | |
807 | return NULL; | |
808 | ||
aa3d1fae | 809 | buf->len = size; |
215d0678 | 810 | dprintk("RPC: %5u allocated buffer of size %zu at %p\n", |
c5a4dd8b | 811 | task->tk_pid, size, buf); |
aa3d1fae | 812 | return &buf->data; |
1da177e4 | 813 | } |
12444809 | 814 | EXPORT_SYMBOL_GPL(rpc_malloc); |
1da177e4 | 815 | |
02107148 CL |
816 | /** |
817 | * rpc_free - free buffer allocated via rpc_malloc | |
c5a4dd8b | 818 | * @buffer: buffer to free |
02107148 CL |
819 | * |
820 | */ | |
c5a4dd8b | 821 | void rpc_free(void *buffer) |
1da177e4 | 822 | { |
aa3d1fae CL |
823 | size_t size; |
824 | struct rpc_buffer *buf; | |
02107148 | 825 | |
c5a4dd8b CL |
826 | if (!buffer) |
827 | return; | |
aa3d1fae CL |
828 | |
829 | buf = container_of(buffer, struct rpc_buffer, data); | |
830 | size = buf->len; | |
c5a4dd8b | 831 | |
215d0678 | 832 | dprintk("RPC: freeing buffer of size %zu at %p\n", |
c5a4dd8b | 833 | size, buf); |
aa3d1fae | 834 | |
c5a4dd8b CL |
835 | if (size <= RPC_BUFFER_MAXSIZE) |
836 | mempool_free(buf, rpc_buffer_mempool); | |
837 | else | |
838 | kfree(buf); | |
1da177e4 | 839 | } |
12444809 | 840 | EXPORT_SYMBOL_GPL(rpc_free); |
1da177e4 LT |
841 | |
842 | /* | |
843 | * Creation and deletion of RPC task structures | |
844 | */ | |
47fe0648 | 845 | static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data) |
1da177e4 LT |
846 | { |
847 | memset(task, 0, sizeof(*task)); | |
44c28873 | 848 | atomic_set(&task->tk_count, 1); |
84115e1c TM |
849 | task->tk_flags = task_setup_data->flags; |
850 | task->tk_ops = task_setup_data->callback_ops; | |
851 | task->tk_calldata = task_setup_data->callback_data; | |
6529eba0 | 852 | INIT_LIST_HEAD(&task->tk_task); |
1da177e4 | 853 | |
3ff7576d TM |
854 | task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW; |
855 | task->tk_owner = current->tgid; | |
1da177e4 LT |
856 | |
857 | /* Initialize workqueue for async tasks */ | |
32bfb5c0 | 858 | task->tk_workqueue = task_setup_data->workqueue; |
1da177e4 | 859 | |
84115e1c TM |
860 | if (task->tk_ops->rpc_call_prepare != NULL) |
861 | task->tk_action = rpc_prepare_task; | |
963d8fe5 | 862 | |
7fdcf13b | 863 | rpc_init_task_statistics(task); |
ef759a2e | 864 | |
46121cf7 | 865 | dprintk("RPC: new task initialized, procpid %u\n", |
ba25f9dc | 866 | task_pid_nr(current)); |
1da177e4 LT |
867 | } |
868 | ||
869 | static struct rpc_task * | |
870 | rpc_alloc_task(void) | |
871 | { | |
872 | return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS); | |
873 | } | |
874 | ||
1da177e4 | 875 | /* |
90c5755f | 876 | * Create a new task for the specified client. |
1da177e4 | 877 | */ |
84115e1c | 878 | struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data) |
1da177e4 | 879 | { |
e8f5d77c TM |
880 | struct rpc_task *task = setup_data->task; |
881 | unsigned short flags = 0; | |
882 | ||
883 | if (task == NULL) { | |
884 | task = rpc_alloc_task(); | |
19445b99 TM |
885 | if (task == NULL) { |
886 | rpc_release_calldata(setup_data->callback_ops, | |
887 | setup_data->callback_data); | |
888 | return ERR_PTR(-ENOMEM); | |
889 | } | |
e8f5d77c TM |
890 | flags = RPC_TASK_DYNAMIC; |
891 | } | |
1da177e4 | 892 | |
84115e1c | 893 | rpc_init_task(task, setup_data); |
e8f5d77c | 894 | task->tk_flags |= flags; |
46121cf7 | 895 | dprintk("RPC: allocated task %p\n", task); |
1da177e4 | 896 | return task; |
1da177e4 LT |
897 | } |
898 | ||
32bfb5c0 | 899 | static void rpc_free_task(struct rpc_task *task) |
1da177e4 | 900 | { |
963d8fe5 TM |
901 | const struct rpc_call_ops *tk_ops = task->tk_ops; |
902 | void *calldata = task->tk_calldata; | |
1da177e4 | 903 | |
5e4424af TM |
904 | if (task->tk_flags & RPC_TASK_DYNAMIC) { |
905 | dprintk("RPC: %5u freeing task\n", task->tk_pid); | |
906 | mempool_free(task, rpc_task_mempool); | |
907 | } | |
32bfb5c0 TM |
908 | rpc_release_calldata(tk_ops, calldata); |
909 | } | |
910 | ||
911 | static void rpc_async_release(struct work_struct *work) | |
912 | { | |
913 | rpc_free_task(container_of(work, struct rpc_task, u.tk_work)); | |
914 | } | |
915 | ||
bf294b41 | 916 | static void rpc_release_resources_task(struct rpc_task *task) |
32bfb5c0 | 917 | { |
e6b3c4db TM |
918 | if (task->tk_rqstp) |
919 | xprt_release(task); | |
a271c5a0 | 920 | if (task->tk_msg.rpc_cred) { |
a17c2153 | 921 | put_rpccred(task->tk_msg.rpc_cred); |
a271c5a0 OH |
922 | task->tk_msg.rpc_cred = NULL; |
923 | } | |
58f9612c | 924 | rpc_task_release_client(task); |
bf294b41 TM |
925 | } |
926 | ||
927 | static void rpc_final_put_task(struct rpc_task *task, | |
928 | struct workqueue_struct *q) | |
929 | { | |
930 | if (q != NULL) { | |
32bfb5c0 | 931 | INIT_WORK(&task->u.tk_work, rpc_async_release); |
bf294b41 | 932 | queue_work(q, &task->u.tk_work); |
32bfb5c0 TM |
933 | } else |
934 | rpc_free_task(task); | |
e6b3c4db | 935 | } |
bf294b41 TM |
936 | |
937 | static void rpc_do_put_task(struct rpc_task *task, struct workqueue_struct *q) | |
938 | { | |
939 | if (atomic_dec_and_test(&task->tk_count)) { | |
940 | rpc_release_resources_task(task); | |
941 | rpc_final_put_task(task, q); | |
942 | } | |
943 | } | |
944 | ||
945 | void rpc_put_task(struct rpc_task *task) | |
946 | { | |
947 | rpc_do_put_task(task, NULL); | |
948 | } | |
e8914c65 | 949 | EXPORT_SYMBOL_GPL(rpc_put_task); |
e6b3c4db | 950 | |
bf294b41 TM |
951 | void rpc_put_task_async(struct rpc_task *task) |
952 | { | |
953 | rpc_do_put_task(task, task->tk_workqueue); | |
954 | } | |
955 | EXPORT_SYMBOL_GPL(rpc_put_task_async); | |
956 | ||
bde8f00c | 957 | static void rpc_release_task(struct rpc_task *task) |
e6b3c4db | 958 | { |
46121cf7 | 959 | dprintk("RPC: %5u release task\n", task->tk_pid); |
1da177e4 | 960 | |
1da177e4 | 961 | BUG_ON (RPC_IS_QUEUED(task)); |
1da177e4 | 962 | |
bf294b41 | 963 | rpc_release_resources_task(task); |
e6b3c4db | 964 | |
bf294b41 TM |
965 | /* |
966 | * Note: at this point we have been removed from rpc_clnt->cl_tasks, | |
967 | * so it should be safe to use task->tk_count as a test for whether | |
968 | * or not any other processes still hold references to our rpc_task. | |
969 | */ | |
970 | if (atomic_read(&task->tk_count) != 1 + !RPC_IS_ASYNC(task)) { | |
971 | /* Wake up anyone who may be waiting for task completion */ | |
972 | if (!rpc_complete_task(task)) | |
973 | return; | |
974 | } else { | |
975 | if (!atomic_dec_and_test(&task->tk_count)) | |
976 | return; | |
977 | } | |
978 | rpc_final_put_task(task, task->tk_workqueue); | |
1da177e4 LT |
979 | } |
980 | ||
b247bbf1 TM |
981 | int rpciod_up(void) |
982 | { | |
983 | return try_module_get(THIS_MODULE) ? 0 : -EINVAL; | |
984 | } | |
985 | ||
986 | void rpciod_down(void) | |
987 | { | |
988 | module_put(THIS_MODULE); | |
989 | } | |
990 | ||
1da177e4 | 991 | /* |
b247bbf1 | 992 | * Start up the rpciod workqueue. |
1da177e4 | 993 | */ |
b247bbf1 | 994 | static int rpciod_start(void) |
1da177e4 LT |
995 | { |
996 | struct workqueue_struct *wq; | |
ab418d70 | 997 | |
1da177e4 LT |
998 | /* |
999 | * Create the rpciod thread and wait for it to start. | |
1000 | */ | |
ab418d70 | 1001 | dprintk("RPC: creating workqueue rpciod\n"); |
ada609ee | 1002 | wq = alloc_workqueue("rpciod", WQ_MEM_RECLAIM, 0); |
1da177e4 | 1003 | rpciod_workqueue = wq; |
b247bbf1 | 1004 | return rpciod_workqueue != NULL; |
1da177e4 LT |
1005 | } |
1006 | ||
b247bbf1 | 1007 | static void rpciod_stop(void) |
1da177e4 | 1008 | { |
b247bbf1 | 1009 | struct workqueue_struct *wq = NULL; |
ab418d70 | 1010 | |
b247bbf1 TM |
1011 | if (rpciod_workqueue == NULL) |
1012 | return; | |
ab418d70 | 1013 | dprintk("RPC: destroying workqueue rpciod\n"); |
1da177e4 | 1014 | |
b247bbf1 TM |
1015 | wq = rpciod_workqueue; |
1016 | rpciod_workqueue = NULL; | |
1017 | destroy_workqueue(wq); | |
1da177e4 LT |
1018 | } |
1019 | ||
1da177e4 LT |
1020 | void |
1021 | rpc_destroy_mempool(void) | |
1022 | { | |
b247bbf1 | 1023 | rpciod_stop(); |
1da177e4 LT |
1024 | if (rpc_buffer_mempool) |
1025 | mempool_destroy(rpc_buffer_mempool); | |
1026 | if (rpc_task_mempool) | |
1027 | mempool_destroy(rpc_task_mempool); | |
1a1d92c1 AD |
1028 | if (rpc_task_slabp) |
1029 | kmem_cache_destroy(rpc_task_slabp); | |
1030 | if (rpc_buffer_slabp) | |
1031 | kmem_cache_destroy(rpc_buffer_slabp); | |
f6a1cc89 | 1032 | rpc_destroy_wait_queue(&delay_queue); |
1da177e4 LT |
1033 | } |
1034 | ||
1035 | int | |
1036 | rpc_init_mempool(void) | |
1037 | { | |
f6a1cc89 TM |
1038 | /* |
1039 | * The following is not strictly a mempool initialisation, | |
1040 | * but there is no harm in doing it here | |
1041 | */ | |
1042 | rpc_init_wait_queue(&delay_queue, "delayq"); | |
1043 | if (!rpciod_start()) | |
1044 | goto err_nomem; | |
1045 | ||
1da177e4 LT |
1046 | rpc_task_slabp = kmem_cache_create("rpc_tasks", |
1047 | sizeof(struct rpc_task), | |
1048 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1049 | NULL); |
1da177e4 LT |
1050 | if (!rpc_task_slabp) |
1051 | goto err_nomem; | |
1052 | rpc_buffer_slabp = kmem_cache_create("rpc_buffers", | |
1053 | RPC_BUFFER_MAXSIZE, | |
1054 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1055 | NULL); |
1da177e4 LT |
1056 | if (!rpc_buffer_slabp) |
1057 | goto err_nomem; | |
93d2341c MD |
1058 | rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE, |
1059 | rpc_task_slabp); | |
1da177e4 LT |
1060 | if (!rpc_task_mempool) |
1061 | goto err_nomem; | |
93d2341c MD |
1062 | rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE, |
1063 | rpc_buffer_slabp); | |
1da177e4 LT |
1064 | if (!rpc_buffer_mempool) |
1065 | goto err_nomem; | |
1066 | return 0; | |
1067 | err_nomem: | |
1068 | rpc_destroy_mempool(); | |
1069 | return -ENOMEM; | |
1070 | } |