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> |
a1231fda | 22 | #include <linux/sched/mm.h> |
1da177e4 LT |
23 | |
24 | #include <linux/sunrpc/clnt.h> | |
1da177e4 | 25 | |
6951867b BH |
26 | #include "sunrpc.h" |
27 | ||
f895b252 | 28 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
1da177e4 | 29 | #define RPCDBG_FACILITY RPCDBG_SCHED |
1da177e4 LT |
30 | #endif |
31 | ||
82b0a4c3 TM |
32 | #define CREATE_TRACE_POINTS |
33 | #include <trace/events/sunrpc.h> | |
34 | ||
1da177e4 LT |
35 | /* |
36 | * RPC slabs and memory pools | |
37 | */ | |
38 | #define RPC_BUFFER_MAXSIZE (2048) | |
39 | #define RPC_BUFFER_POOLSIZE (8) | |
40 | #define RPC_TASK_POOLSIZE (8) | |
e18b890b CL |
41 | static struct kmem_cache *rpc_task_slabp __read_mostly; |
42 | static struct kmem_cache *rpc_buffer_slabp __read_mostly; | |
ba89966c ED |
43 | static mempool_t *rpc_task_mempool __read_mostly; |
44 | static mempool_t *rpc_buffer_mempool __read_mostly; | |
1da177e4 | 45 | |
65f27f38 | 46 | static void rpc_async_schedule(struct work_struct *); |
bde8f00c | 47 | static void rpc_release_task(struct rpc_task *task); |
ff861c4d | 48 | static void __rpc_queue_timer_fn(struct timer_list *t); |
1da177e4 | 49 | |
1da177e4 LT |
50 | /* |
51 | * RPC tasks sit here while waiting for conditions to improve. | |
52 | */ | |
a4a87499 | 53 | static struct rpc_wait_queue delay_queue; |
1da177e4 | 54 | |
1da177e4 LT |
55 | /* |
56 | * rpciod-related stuff | |
57 | */ | |
40a5f1b1 TM |
58 | struct workqueue_struct *rpciod_workqueue __read_mostly; |
59 | struct workqueue_struct *xprtiod_workqueue __read_mostly; | |
1da177e4 | 60 | |
1da177e4 LT |
61 | /* |
62 | * Disable the timer for a given RPC task. Should be called with | |
63 | * queue->lock and bh_disabled in order to avoid races within | |
64 | * rpc_run_timer(). | |
65 | */ | |
5d00837b | 66 | static void |
eb276c0e | 67 | __rpc_disable_timer(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 68 | { |
36df9aae TM |
69 | if (task->tk_timeout == 0) |
70 | return; | |
46121cf7 | 71 | dprintk("RPC: %5u disabling timer\n", task->tk_pid); |
1da177e4 | 72 | task->tk_timeout = 0; |
36df9aae | 73 | list_del(&task->u.tk_wait.timer_list); |
eb276c0e TM |
74 | if (list_empty(&queue->timer_list.list)) |
75 | del_timer(&queue->timer_list.timer); | |
36df9aae TM |
76 | } |
77 | ||
78 | static void | |
79 | rpc_set_queue_timer(struct rpc_wait_queue *queue, unsigned long expires) | |
80 | { | |
81 | queue->timer_list.expires = expires; | |
82 | mod_timer(&queue->timer_list.timer, expires); | |
1da177e4 LT |
83 | } |
84 | ||
1da177e4 LT |
85 | /* |
86 | * Set up a timer for the current task. | |
87 | */ | |
5d00837b | 88 | static void |
eb276c0e | 89 | __rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 LT |
90 | { |
91 | if (!task->tk_timeout) | |
92 | return; | |
93 | ||
55cc1d78 NMG |
94 | dprintk("RPC: %5u setting alarm for %u ms\n", |
95 | task->tk_pid, jiffies_to_msecs(task->tk_timeout)); | |
1da177e4 | 96 | |
eb276c0e TM |
97 | task->u.tk_wait.expires = jiffies + task->tk_timeout; |
98 | if (list_empty(&queue->timer_list.list) || time_before(task->u.tk_wait.expires, queue->timer_list.expires)) | |
99 | rpc_set_queue_timer(queue, task->u.tk_wait.expires); | |
100 | list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list); | |
1da177e4 LT |
101 | } |
102 | ||
c05eecf6 TM |
103 | static void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority) |
104 | { | |
edd2e36f | 105 | if (queue->priority != priority) { |
edd2e36f | 106 | queue->priority = priority; |
f42f7c28 | 107 | queue->nr = 1U << priority; |
edd2e36f | 108 | } |
c05eecf6 TM |
109 | } |
110 | ||
c05eecf6 TM |
111 | static void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue) |
112 | { | |
113 | rpc_set_waitqueue_priority(queue, queue->maxpriority); | |
c05eecf6 TM |
114 | } |
115 | ||
1da177e4 | 116 | /* |
f42f7c28 | 117 | * Add a request to a queue list |
1da177e4 | 118 | */ |
f42f7c28 TM |
119 | static void |
120 | __rpc_list_enqueue_task(struct list_head *q, struct rpc_task *task) | |
1da177e4 | 121 | { |
1da177e4 LT |
122 | struct rpc_task *t; |
123 | ||
1da177e4 | 124 | list_for_each_entry(t, q, u.tk_wait.list) { |
3ff7576d | 125 | if (t->tk_owner == task->tk_owner) { |
f42f7c28 TM |
126 | list_add_tail(&task->u.tk_wait.links, |
127 | &t->u.tk_wait.links); | |
128 | /* Cache the queue head in task->u.tk_wait.list */ | |
129 | task->u.tk_wait.list.next = q; | |
130 | task->u.tk_wait.list.prev = NULL; | |
1da177e4 LT |
131 | return; |
132 | } | |
133 | } | |
f42f7c28 | 134 | INIT_LIST_HEAD(&task->u.tk_wait.links); |
1da177e4 LT |
135 | list_add_tail(&task->u.tk_wait.list, q); |
136 | } | |
137 | ||
f42f7c28 TM |
138 | /* |
139 | * Remove request from a queue list | |
140 | */ | |
141 | static void | |
142 | __rpc_list_dequeue_task(struct rpc_task *task) | |
143 | { | |
144 | struct list_head *q; | |
145 | struct rpc_task *t; | |
146 | ||
147 | if (task->u.tk_wait.list.prev == NULL) { | |
148 | list_del(&task->u.tk_wait.links); | |
149 | return; | |
150 | } | |
151 | if (!list_empty(&task->u.tk_wait.links)) { | |
152 | t = list_first_entry(&task->u.tk_wait.links, | |
153 | struct rpc_task, | |
154 | u.tk_wait.links); | |
155 | /* Assume __rpc_list_enqueue_task() cached the queue head */ | |
156 | q = t->u.tk_wait.list.next; | |
157 | list_add_tail(&t->u.tk_wait.list, q); | |
158 | list_del(&task->u.tk_wait.links); | |
159 | } | |
160 | list_del(&task->u.tk_wait.list); | |
161 | } | |
162 | ||
163 | /* | |
164 | * Add new request to a priority queue. | |
165 | */ | |
166 | static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, | |
167 | struct rpc_task *task, | |
168 | unsigned char queue_priority) | |
169 | { | |
170 | if (unlikely(queue_priority > queue->maxpriority)) | |
171 | queue_priority = queue->maxpriority; | |
172 | __rpc_list_enqueue_task(&queue->tasks[queue_priority], task); | |
173 | } | |
174 | ||
1da177e4 LT |
175 | /* |
176 | * Add new request to wait queue. | |
177 | * | |
178 | * Swapper tasks always get inserted at the head of the queue. | |
179 | * This should avoid many nasty memory deadlocks and hopefully | |
180 | * improve overall performance. | |
181 | * Everyone else gets appended to the queue to ensure proper FIFO behavior. | |
182 | */ | |
3b27bad7 TM |
183 | static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, |
184 | struct rpc_task *task, | |
185 | unsigned char queue_priority) | |
1da177e4 | 186 | { |
2bd4eef8 WAA |
187 | WARN_ON_ONCE(RPC_IS_QUEUED(task)); |
188 | if (RPC_IS_QUEUED(task)) | |
189 | return; | |
1da177e4 LT |
190 | |
191 | if (RPC_IS_PRIORITY(queue)) | |
3b27bad7 | 192 | __rpc_add_wait_queue_priority(queue, task, queue_priority); |
1da177e4 LT |
193 | else if (RPC_IS_SWAPPER(task)) |
194 | list_add(&task->u.tk_wait.list, &queue->tasks[0]); | |
195 | else | |
196 | list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]); | |
96ef13b2 | 197 | task->tk_waitqueue = queue; |
e19b63da | 198 | queue->qlen++; |
1166fde6 TM |
199 | /* barrier matches the read in rpc_wake_up_task_queue_locked() */ |
200 | smp_wmb(); | |
1da177e4 LT |
201 | rpc_set_queued(task); |
202 | ||
46121cf7 CL |
203 | dprintk("RPC: %5u added to queue %p \"%s\"\n", |
204 | task->tk_pid, queue, rpc_qname(queue)); | |
1da177e4 LT |
205 | } |
206 | ||
207 | /* | |
208 | * Remove request from a priority queue. | |
209 | */ | |
210 | static void __rpc_remove_wait_queue_priority(struct rpc_task *task) | |
211 | { | |
f42f7c28 | 212 | __rpc_list_dequeue_task(task); |
1da177e4 LT |
213 | } |
214 | ||
215 | /* | |
216 | * Remove request from queue. | |
217 | * Note: must be called with spin lock held. | |
218 | */ | |
96ef13b2 | 219 | static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 220 | { |
eb276c0e | 221 | __rpc_disable_timer(queue, task); |
1da177e4 LT |
222 | if (RPC_IS_PRIORITY(queue)) |
223 | __rpc_remove_wait_queue_priority(task); | |
f42f7c28 TM |
224 | else |
225 | list_del(&task->u.tk_wait.list); | |
e19b63da | 226 | queue->qlen--; |
46121cf7 CL |
227 | dprintk("RPC: %5u removed from queue %p \"%s\"\n", |
228 | task->tk_pid, queue, rpc_qname(queue)); | |
1da177e4 LT |
229 | } |
230 | ||
3ff7576d | 231 | static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues) |
1da177e4 LT |
232 | { |
233 | int i; | |
234 | ||
235 | spin_lock_init(&queue->lock); | |
236 | for (i = 0; i < ARRAY_SIZE(queue->tasks); i++) | |
237 | INIT_LIST_HEAD(&queue->tasks[i]); | |
3ff7576d | 238 | queue->maxpriority = nr_queues - 1; |
1da177e4 | 239 | rpc_reset_waitqueue_priority(queue); |
36df9aae | 240 | queue->qlen = 0; |
ff861c4d | 241 | timer_setup(&queue->timer_list.timer, __rpc_queue_timer_fn, 0); |
36df9aae | 242 | INIT_LIST_HEAD(&queue->timer_list.list); |
2f09c242 | 243 | rpc_assign_waitqueue_name(queue, qname); |
1da177e4 LT |
244 | } |
245 | ||
246 | void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
247 | { | |
3ff7576d | 248 | __rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY); |
1da177e4 | 249 | } |
689cf5c1 | 250 | EXPORT_SYMBOL_GPL(rpc_init_priority_wait_queue); |
1da177e4 LT |
251 | |
252 | void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
253 | { | |
3ff7576d | 254 | __rpc_init_priority_wait_queue(queue, qname, 1); |
1da177e4 | 255 | } |
e8914c65 | 256 | EXPORT_SYMBOL_GPL(rpc_init_wait_queue); |
1da177e4 | 257 | |
f6a1cc89 TM |
258 | void rpc_destroy_wait_queue(struct rpc_wait_queue *queue) |
259 | { | |
36df9aae | 260 | del_timer_sync(&queue->timer_list.timer); |
f6a1cc89 TM |
261 | } |
262 | EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue); | |
263 | ||
dfd01f02 | 264 | static int rpc_wait_bit_killable(struct wait_bit_key *key, int mode) |
44c28873 | 265 | { |
416ad3c9 | 266 | freezable_schedule_unsafe(); |
dfd01f02 PZ |
267 | if (signal_pending_state(mode, current)) |
268 | return -ERESTARTSYS; | |
44c28873 TM |
269 | return 0; |
270 | } | |
271 | ||
1306729b | 272 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS) |
c44fe705 TM |
273 | static void rpc_task_set_debuginfo(struct rpc_task *task) |
274 | { | |
275 | static atomic_t rpc_pid; | |
276 | ||
c44fe705 TM |
277 | task->tk_pid = atomic_inc_return(&rpc_pid); |
278 | } | |
279 | #else | |
280 | static inline void rpc_task_set_debuginfo(struct rpc_task *task) | |
281 | { | |
282 | } | |
283 | #endif | |
284 | ||
e6b3c4db TM |
285 | static void rpc_set_active(struct rpc_task *task) |
286 | { | |
c44fe705 | 287 | rpc_task_set_debuginfo(task); |
58f9612c | 288 | set_bit(RPC_TASK_ACTIVE, &task->tk_runstate); |
e671edb9 | 289 | trace_rpc_task_begin(task, NULL); |
e6b3c4db TM |
290 | } |
291 | ||
44c28873 TM |
292 | /* |
293 | * Mark an RPC call as having completed by clearing the 'active' bit | |
bf294b41 | 294 | * and then waking up all tasks that were sleeping. |
44c28873 | 295 | */ |
bf294b41 | 296 | static int rpc_complete_task(struct rpc_task *task) |
44c28873 | 297 | { |
bf294b41 TM |
298 | void *m = &task->tk_runstate; |
299 | wait_queue_head_t *wq = bit_waitqueue(m, RPC_TASK_ACTIVE); | |
300 | struct wait_bit_key k = __WAIT_BIT_KEY_INITIALIZER(m, RPC_TASK_ACTIVE); | |
301 | unsigned long flags; | |
302 | int ret; | |
303 | ||
e671edb9 | 304 | trace_rpc_task_complete(task, NULL); |
82b0a4c3 | 305 | |
bf294b41 | 306 | spin_lock_irqsave(&wq->lock, flags); |
e6b3c4db | 307 | clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate); |
bf294b41 TM |
308 | ret = atomic_dec_and_test(&task->tk_count); |
309 | if (waitqueue_active(wq)) | |
ac5be6b4 | 310 | __wake_up_locked_key(wq, TASK_NORMAL, &k); |
bf294b41 TM |
311 | spin_unlock_irqrestore(&wq->lock, flags); |
312 | return ret; | |
44c28873 TM |
313 | } |
314 | ||
315 | /* | |
316 | * Allow callers to wait for completion of an RPC call | |
bf294b41 TM |
317 | * |
318 | * Note the use of out_of_line_wait_on_bit() rather than wait_on_bit() | |
319 | * to enforce taking of the wq->lock and hence avoid races with | |
320 | * rpc_complete_task(). | |
44c28873 | 321 | */ |
c1221321 | 322 | int __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *action) |
44c28873 TM |
323 | { |
324 | if (action == NULL) | |
150030b7 | 325 | action = rpc_wait_bit_killable; |
bf294b41 | 326 | return out_of_line_wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE, |
150030b7 | 327 | action, TASK_KILLABLE); |
44c28873 | 328 | } |
e8914c65 | 329 | EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task); |
44c28873 | 330 | |
1da177e4 LT |
331 | /* |
332 | * Make an RPC task runnable. | |
333 | * | |
506026c3 JL |
334 | * Note: If the task is ASYNC, and is being made runnable after sitting on an |
335 | * rpc_wait_queue, this must be called with the queue spinlock held to protect | |
336 | * the wait queue operation. | |
a3c3cac5 TM |
337 | * Note the ordering of rpc_test_and_set_running() and rpc_clear_queued(), |
338 | * which is needed to ensure that __rpc_execute() doesn't loop (due to the | |
339 | * lockless RPC_IS_QUEUED() test) before we've had a chance to test | |
340 | * the RPC_TASK_RUNNING flag. | |
1da177e4 | 341 | */ |
f1dc237c TM |
342 | static void rpc_make_runnable(struct workqueue_struct *wq, |
343 | struct rpc_task *task) | |
1da177e4 | 344 | { |
a3c3cac5 TM |
345 | bool need_wakeup = !rpc_test_and_set_running(task); |
346 | ||
1da177e4 | 347 | rpc_clear_queued(task); |
a3c3cac5 | 348 | if (!need_wakeup) |
cc4dc59e | 349 | return; |
1da177e4 | 350 | if (RPC_IS_ASYNC(task)) { |
65f27f38 | 351 | INIT_WORK(&task->u.tk_work, rpc_async_schedule); |
f1dc237c | 352 | queue_work(wq, &task->u.tk_work); |
1da177e4 | 353 | } else |
96651ab3 | 354 | wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED); |
1da177e4 LT |
355 | } |
356 | ||
1da177e4 LT |
357 | /* |
358 | * Prepare for sleeping on a wait queue. | |
359 | * By always appending tasks to the list we ensure FIFO behavior. | |
360 | * NB: An RPC task will only receive interrupt-driven events as long | |
361 | * as it's on a wait queue. | |
362 | */ | |
3b27bad7 TM |
363 | static void __rpc_sleep_on_priority(struct rpc_wait_queue *q, |
364 | struct rpc_task *task, | |
365 | rpc_action action, | |
366 | unsigned char queue_priority) | |
1da177e4 | 367 | { |
46121cf7 CL |
368 | dprintk("RPC: %5u sleep_on(queue \"%s\" time %lu)\n", |
369 | task->tk_pid, rpc_qname(q), jiffies); | |
1da177e4 | 370 | |
e671edb9 | 371 | trace_rpc_task_sleep(task, q); |
82b0a4c3 | 372 | |
3b27bad7 | 373 | __rpc_add_wait_queue(q, task, queue_priority); |
1da177e4 | 374 | |
f50ad428 | 375 | WARN_ON_ONCE(task->tk_callback != NULL); |
1da177e4 | 376 | task->tk_callback = action; |
eb276c0e | 377 | __rpc_add_timer(q, task); |
1da177e4 LT |
378 | } |
379 | ||
380 | void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task, | |
5d00837b | 381 | rpc_action action) |
1da177e4 | 382 | { |
58f9612c | 383 | /* We shouldn't ever put an inactive task to sleep */ |
e454a7a8 WAA |
384 | WARN_ON_ONCE(!RPC_IS_ACTIVATED(task)); |
385 | if (!RPC_IS_ACTIVATED(task)) { | |
386 | task->tk_status = -EIO; | |
387 | rpc_put_task_async(task); | |
388 | return; | |
389 | } | |
e6b3c4db | 390 | |
1da177e4 LT |
391 | /* |
392 | * Protect the queue operations. | |
393 | */ | |
394 | spin_lock_bh(&q->lock); | |
3b27bad7 | 395 | __rpc_sleep_on_priority(q, task, action, task->tk_priority); |
1da177e4 LT |
396 | spin_unlock_bh(&q->lock); |
397 | } | |
e8914c65 | 398 | EXPORT_SYMBOL_GPL(rpc_sleep_on); |
1da177e4 | 399 | |
3b27bad7 TM |
400 | void rpc_sleep_on_priority(struct rpc_wait_queue *q, struct rpc_task *task, |
401 | rpc_action action, int priority) | |
402 | { | |
403 | /* We shouldn't ever put an inactive task to sleep */ | |
e454a7a8 WAA |
404 | WARN_ON_ONCE(!RPC_IS_ACTIVATED(task)); |
405 | if (!RPC_IS_ACTIVATED(task)) { | |
406 | task->tk_status = -EIO; | |
407 | rpc_put_task_async(task); | |
408 | return; | |
409 | } | |
3b27bad7 TM |
410 | |
411 | /* | |
412 | * Protect the queue operations. | |
413 | */ | |
414 | spin_lock_bh(&q->lock); | |
415 | __rpc_sleep_on_priority(q, task, action, priority - RPC_PRIORITY_LOW); | |
416 | spin_unlock_bh(&q->lock); | |
417 | } | |
1e1093c7 | 418 | EXPORT_SYMBOL_GPL(rpc_sleep_on_priority); |
3b27bad7 | 419 | |
1da177e4 | 420 | /** |
f1dc237c TM |
421 | * __rpc_do_wake_up_task_on_wq - wake up a single rpc_task |
422 | * @wq: workqueue on which to run task | |
96ef13b2 | 423 | * @queue: wait queue |
1da177e4 LT |
424 | * @task: task to be woken up |
425 | * | |
426 | * Caller must hold queue->lock, and have cleared the task queued flag. | |
427 | */ | |
f1dc237c TM |
428 | static void __rpc_do_wake_up_task_on_wq(struct workqueue_struct *wq, |
429 | struct rpc_wait_queue *queue, | |
430 | struct rpc_task *task) | |
1da177e4 | 431 | { |
46121cf7 CL |
432 | dprintk("RPC: %5u __rpc_wake_up_task (now %lu)\n", |
433 | task->tk_pid, jiffies); | |
1da177e4 | 434 | |
1da177e4 LT |
435 | /* Has the task been executed yet? If not, we cannot wake it up! */ |
436 | if (!RPC_IS_ACTIVATED(task)) { | |
437 | printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task); | |
438 | return; | |
439 | } | |
440 | ||
e671edb9 | 441 | trace_rpc_task_wakeup(task, queue); |
82b0a4c3 | 442 | |
96ef13b2 | 443 | __rpc_remove_wait_queue(queue, task); |
1da177e4 | 444 | |
f1dc237c | 445 | rpc_make_runnable(wq, task); |
1da177e4 | 446 | |
46121cf7 | 447 | dprintk("RPC: __rpc_wake_up_task done\n"); |
1da177e4 LT |
448 | } |
449 | ||
450 | /* | |
96ef13b2 | 451 | * Wake up a queued task while the queue lock is being held |
1da177e4 | 452 | */ |
359c48c0 TM |
453 | static struct rpc_task * |
454 | rpc_wake_up_task_on_wq_queue_action_locked(struct workqueue_struct *wq, | |
455 | struct rpc_wait_queue *queue, struct rpc_task *task, | |
456 | bool (*action)(struct rpc_task *, void *), void *data) | |
1da177e4 | 457 | { |
1166fde6 TM |
458 | if (RPC_IS_QUEUED(task)) { |
459 | smp_rmb(); | |
359c48c0 TM |
460 | if (task->tk_waitqueue == queue) { |
461 | if (action == NULL || action(task, data)) { | |
462 | __rpc_do_wake_up_task_on_wq(wq, queue, task); | |
463 | return task; | |
464 | } | |
465 | } | |
1166fde6 | 466 | } |
359c48c0 TM |
467 | return NULL; |
468 | } | |
469 | ||
470 | static void | |
471 | rpc_wake_up_task_on_wq_queue_locked(struct workqueue_struct *wq, | |
472 | struct rpc_wait_queue *queue, struct rpc_task *task) | |
473 | { | |
474 | rpc_wake_up_task_on_wq_queue_action_locked(wq, queue, task, NULL, NULL); | |
1da177e4 LT |
475 | } |
476 | ||
f1dc237c TM |
477 | /* |
478 | * Wake up a queued task while the queue lock is being held | |
479 | */ | |
480 | static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct rpc_task *task) | |
481 | { | |
482 | rpc_wake_up_task_on_wq_queue_locked(rpciod_workqueue, queue, task); | |
483 | } | |
484 | ||
2275cde4 TM |
485 | /* |
486 | * Wake up a task on a specific queue | |
487 | */ | |
488 | void rpc_wake_up_queued_task_on_wq(struct workqueue_struct *wq, | |
489 | struct rpc_wait_queue *queue, | |
490 | struct rpc_task *task) | |
491 | { | |
5ce97039 TM |
492 | if (!RPC_IS_QUEUED(task)) |
493 | return; | |
2275cde4 TM |
494 | spin_lock_bh(&queue->lock); |
495 | rpc_wake_up_task_on_wq_queue_locked(wq, queue, task); | |
496 | spin_unlock_bh(&queue->lock); | |
497 | } | |
498 | ||
1da177e4 | 499 | /* |
96ef13b2 | 500 | * Wake up a task on a specific queue |
1da177e4 | 501 | */ |
96ef13b2 | 502 | void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 503 | { |
5ce97039 TM |
504 | if (!RPC_IS_QUEUED(task)) |
505 | return; | |
5e4424af | 506 | spin_lock_bh(&queue->lock); |
96ef13b2 | 507 | rpc_wake_up_task_queue_locked(queue, task); |
5e4424af | 508 | spin_unlock_bh(&queue->lock); |
1da177e4 | 509 | } |
96ef13b2 TM |
510 | EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task); |
511 | ||
359c48c0 TM |
512 | static bool rpc_task_action_set_status(struct rpc_task *task, void *status) |
513 | { | |
514 | task->tk_status = *(int *)status; | |
515 | return true; | |
516 | } | |
517 | ||
518 | static void | |
519 | rpc_wake_up_task_queue_set_status_locked(struct rpc_wait_queue *queue, | |
520 | struct rpc_task *task, int status) | |
521 | { | |
522 | rpc_wake_up_task_on_wq_queue_action_locked(rpciod_workqueue, queue, | |
523 | task, rpc_task_action_set_status, &status); | |
524 | } | |
525 | ||
526 | /** | |
527 | * rpc_wake_up_queued_task_set_status - wake up a task and set task->tk_status | |
528 | * @queue: pointer to rpc_wait_queue | |
529 | * @task: pointer to rpc_task | |
530 | * @status: integer error value | |
531 | * | |
532 | * If @task is queued on @queue, then it is woken up, and @task->tk_status is | |
533 | * set to the value of @status. | |
534 | */ | |
535 | void | |
536 | rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *queue, | |
537 | struct rpc_task *task, int status) | |
538 | { | |
539 | if (!RPC_IS_QUEUED(task)) | |
540 | return; | |
541 | spin_lock_bh(&queue->lock); | |
542 | rpc_wake_up_task_queue_set_status_locked(queue, task, status); | |
543 | spin_unlock_bh(&queue->lock); | |
544 | } | |
545 | ||
1da177e4 LT |
546 | /* |
547 | * Wake up the next task on a priority queue. | |
548 | */ | |
961a828d | 549 | static struct rpc_task *__rpc_find_next_queued_priority(struct rpc_wait_queue *queue) |
1da177e4 LT |
550 | { |
551 | struct list_head *q; | |
552 | struct rpc_task *task; | |
553 | ||
554 | /* | |
3ff7576d | 555 | * Service a batch of tasks from a single owner. |
1da177e4 LT |
556 | */ |
557 | q = &queue->tasks[queue->priority]; | |
f42f7c28 TM |
558 | if (!list_empty(q) && --queue->nr) { |
559 | task = list_first_entry(q, struct rpc_task, u.tk_wait.list); | |
560 | goto out; | |
1da177e4 LT |
561 | } |
562 | ||
563 | /* | |
564 | * Service the next queue. | |
565 | */ | |
566 | do { | |
567 | if (q == &queue->tasks[0]) | |
568 | q = &queue->tasks[queue->maxpriority]; | |
569 | else | |
570 | q = q - 1; | |
571 | if (!list_empty(q)) { | |
f42f7c28 | 572 | task = list_first_entry(q, struct rpc_task, u.tk_wait.list); |
1da177e4 LT |
573 | goto new_queue; |
574 | } | |
575 | } while (q != &queue->tasks[queue->priority]); | |
576 | ||
577 | rpc_reset_waitqueue_priority(queue); | |
578 | return NULL; | |
579 | ||
580 | new_queue: | |
581 | rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0])); | |
1da177e4 | 582 | out: |
1da177e4 LT |
583 | return task; |
584 | } | |
585 | ||
961a828d TM |
586 | static struct rpc_task *__rpc_find_next_queued(struct rpc_wait_queue *queue) |
587 | { | |
588 | if (RPC_IS_PRIORITY(queue)) | |
589 | return __rpc_find_next_queued_priority(queue); | |
590 | if (!list_empty(&queue->tasks[0])) | |
591 | return list_first_entry(&queue->tasks[0], struct rpc_task, u.tk_wait.list); | |
592 | return NULL; | |
593 | } | |
594 | ||
1da177e4 | 595 | /* |
961a828d | 596 | * Wake up the first task on the wait queue. |
1da177e4 | 597 | */ |
f1dc237c TM |
598 | struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq, |
599 | struct rpc_wait_queue *queue, | |
961a828d | 600 | bool (*func)(struct rpc_task *, void *), void *data) |
1da177e4 LT |
601 | { |
602 | struct rpc_task *task = NULL; | |
603 | ||
961a828d | 604 | dprintk("RPC: wake_up_first(%p \"%s\")\n", |
46121cf7 | 605 | queue, rpc_qname(queue)); |
5e4424af | 606 | spin_lock_bh(&queue->lock); |
961a828d | 607 | task = __rpc_find_next_queued(queue); |
359c48c0 TM |
608 | if (task != NULL) |
609 | task = rpc_wake_up_task_on_wq_queue_action_locked(wq, queue, | |
610 | task, func, data); | |
5e4424af | 611 | spin_unlock_bh(&queue->lock); |
1da177e4 LT |
612 | |
613 | return task; | |
614 | } | |
f1dc237c TM |
615 | |
616 | /* | |
617 | * Wake up the first task on the wait queue. | |
618 | */ | |
619 | struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *queue, | |
620 | bool (*func)(struct rpc_task *, void *), void *data) | |
621 | { | |
622 | return rpc_wake_up_first_on_wq(rpciod_workqueue, queue, func, data); | |
623 | } | |
961a828d TM |
624 | EXPORT_SYMBOL_GPL(rpc_wake_up_first); |
625 | ||
626 | static bool rpc_wake_up_next_func(struct rpc_task *task, void *data) | |
627 | { | |
628 | return true; | |
629 | } | |
630 | ||
631 | /* | |
632 | * Wake up the next task on the wait queue. | |
633 | */ | |
634 | struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *queue) | |
635 | { | |
636 | return rpc_wake_up_first(queue, rpc_wake_up_next_func, NULL); | |
637 | } | |
e8914c65 | 638 | EXPORT_SYMBOL_GPL(rpc_wake_up_next); |
1da177e4 LT |
639 | |
640 | /** | |
641 | * rpc_wake_up - wake up all rpc_tasks | |
642 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
643 | * | |
644 | * Grabs queue->lock | |
645 | */ | |
646 | void rpc_wake_up(struct rpc_wait_queue *queue) | |
647 | { | |
1da177e4 | 648 | struct list_head *head; |
e6d83d55 | 649 | |
5e4424af | 650 | spin_lock_bh(&queue->lock); |
1da177e4 LT |
651 | head = &queue->tasks[queue->maxpriority]; |
652 | for (;;) { | |
540a0f75 TM |
653 | while (!list_empty(head)) { |
654 | struct rpc_task *task; | |
655 | task = list_first_entry(head, | |
656 | struct rpc_task, | |
657 | u.tk_wait.list); | |
96ef13b2 | 658 | rpc_wake_up_task_queue_locked(queue, task); |
540a0f75 | 659 | } |
1da177e4 LT |
660 | if (head == &queue->tasks[0]) |
661 | break; | |
662 | head--; | |
663 | } | |
5e4424af | 664 | spin_unlock_bh(&queue->lock); |
1da177e4 | 665 | } |
e8914c65 | 666 | EXPORT_SYMBOL_GPL(rpc_wake_up); |
1da177e4 LT |
667 | |
668 | /** | |
669 | * rpc_wake_up_status - wake up all rpc_tasks and set their status value. | |
670 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
671 | * @status: status value to set | |
672 | * | |
673 | * Grabs queue->lock | |
674 | */ | |
675 | void rpc_wake_up_status(struct rpc_wait_queue *queue, int status) | |
676 | { | |
677 | struct list_head *head; | |
1da177e4 | 678 | |
5e4424af | 679 | spin_lock_bh(&queue->lock); |
1da177e4 LT |
680 | head = &queue->tasks[queue->maxpriority]; |
681 | for (;;) { | |
540a0f75 TM |
682 | while (!list_empty(head)) { |
683 | struct rpc_task *task; | |
684 | task = list_first_entry(head, | |
685 | struct rpc_task, | |
686 | u.tk_wait.list); | |
1da177e4 | 687 | task->tk_status = status; |
96ef13b2 | 688 | rpc_wake_up_task_queue_locked(queue, task); |
1da177e4 LT |
689 | } |
690 | if (head == &queue->tasks[0]) | |
691 | break; | |
692 | head--; | |
693 | } | |
5e4424af | 694 | spin_unlock_bh(&queue->lock); |
1da177e4 | 695 | } |
e8914c65 | 696 | EXPORT_SYMBOL_GPL(rpc_wake_up_status); |
1da177e4 | 697 | |
ff861c4d | 698 | static void __rpc_queue_timer_fn(struct timer_list *t) |
36df9aae | 699 | { |
ff861c4d | 700 | struct rpc_wait_queue *queue = from_timer(queue, t, timer_list.timer); |
36df9aae TM |
701 | struct rpc_task *task, *n; |
702 | unsigned long expires, now, timeo; | |
703 | ||
704 | spin_lock(&queue->lock); | |
705 | expires = now = jiffies; | |
706 | list_for_each_entry_safe(task, n, &queue->timer_list.list, u.tk_wait.timer_list) { | |
707 | timeo = task->u.tk_wait.expires; | |
708 | if (time_after_eq(now, timeo)) { | |
36df9aae TM |
709 | dprintk("RPC: %5u timeout\n", task->tk_pid); |
710 | task->tk_status = -ETIMEDOUT; | |
711 | rpc_wake_up_task_queue_locked(queue, task); | |
712 | continue; | |
713 | } | |
714 | if (expires == now || time_after(expires, timeo)) | |
715 | expires = timeo; | |
716 | } | |
717 | if (!list_empty(&queue->timer_list.list)) | |
718 | rpc_set_queue_timer(queue, expires); | |
719 | spin_unlock(&queue->lock); | |
720 | } | |
721 | ||
8014793b TM |
722 | static void __rpc_atrun(struct rpc_task *task) |
723 | { | |
6bd14416 TM |
724 | if (task->tk_status == -ETIMEDOUT) |
725 | task->tk_status = 0; | |
8014793b TM |
726 | } |
727 | ||
1da177e4 LT |
728 | /* |
729 | * Run a task at a later time | |
730 | */ | |
8014793b | 731 | void rpc_delay(struct rpc_task *task, unsigned long delay) |
1da177e4 LT |
732 | { |
733 | task->tk_timeout = delay; | |
5d00837b | 734 | rpc_sleep_on(&delay_queue, task, __rpc_atrun); |
1da177e4 | 735 | } |
e8914c65 | 736 | EXPORT_SYMBOL_GPL(rpc_delay); |
1da177e4 | 737 | |
4ce70ada TM |
738 | /* |
739 | * Helper to call task->tk_ops->rpc_call_prepare | |
740 | */ | |
aae2006e | 741 | void rpc_prepare_task(struct rpc_task *task) |
4ce70ada TM |
742 | { |
743 | task->tk_ops->rpc_call_prepare(task, task->tk_calldata); | |
744 | } | |
745 | ||
7fdcf13b TM |
746 | static void |
747 | rpc_init_task_statistics(struct rpc_task *task) | |
748 | { | |
749 | /* Initialize retry counters */ | |
750 | task->tk_garb_retry = 2; | |
751 | task->tk_cred_retry = 2; | |
752 | task->tk_rebind_retry = 2; | |
753 | ||
754 | /* starting timestamp */ | |
755 | task->tk_start = ktime_get(); | |
756 | } | |
757 | ||
758 | static void | |
759 | rpc_reset_task_statistics(struct rpc_task *task) | |
760 | { | |
761 | task->tk_timeouts = 0; | |
762 | task->tk_flags &= ~(RPC_CALL_MAJORSEEN|RPC_TASK_KILLED|RPC_TASK_SENT); | |
763 | ||
764 | rpc_init_task_statistics(task); | |
765 | } | |
766 | ||
d05fdb0c | 767 | /* |
963d8fe5 | 768 | * Helper that calls task->tk_ops->rpc_call_done if it exists |
d05fdb0c | 769 | */ |
abbcf28f | 770 | void rpc_exit_task(struct rpc_task *task) |
d05fdb0c | 771 | { |
abbcf28f | 772 | task->tk_action = NULL; |
963d8fe5 TM |
773 | if (task->tk_ops->rpc_call_done != NULL) { |
774 | task->tk_ops->rpc_call_done(task, task->tk_calldata); | |
d05fdb0c | 775 | if (task->tk_action != NULL) { |
abbcf28f TM |
776 | WARN_ON(RPC_ASSASSINATED(task)); |
777 | /* Always release the RPC slot and buffer memory */ | |
778 | xprt_release(task); | |
7fdcf13b | 779 | rpc_reset_task_statistics(task); |
d05fdb0c TM |
780 | } |
781 | } | |
d05fdb0c | 782 | } |
d9b6cd94 TM |
783 | |
784 | void rpc_exit(struct rpc_task *task, int status) | |
785 | { | |
786 | task->tk_status = status; | |
787 | task->tk_action = rpc_exit_task; | |
6b5f5900 | 788 | rpc_wake_up_queued_task(task->tk_waitqueue, task); |
d9b6cd94 TM |
789 | } |
790 | EXPORT_SYMBOL_GPL(rpc_exit); | |
d05fdb0c | 791 | |
bbd5a1f9 TM |
792 | void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata) |
793 | { | |
a86dc496 | 794 | if (ops->rpc_release != NULL) |
bbd5a1f9 | 795 | ops->rpc_release(calldata); |
bbd5a1f9 TM |
796 | } |
797 | ||
1da177e4 LT |
798 | /* |
799 | * This is the RPC `scheduler' (or rather, the finite state machine). | |
800 | */ | |
2efef837 | 801 | static void __rpc_execute(struct rpc_task *task) |
1da177e4 | 802 | { |
eb9b55ab TM |
803 | struct rpc_wait_queue *queue; |
804 | int task_is_async = RPC_IS_ASYNC(task); | |
805 | int status = 0; | |
1da177e4 | 806 | |
46121cf7 CL |
807 | dprintk("RPC: %5u __rpc_execute flags=0x%x\n", |
808 | task->tk_pid, task->tk_flags); | |
1da177e4 | 809 | |
2bd4eef8 WAA |
810 | WARN_ON_ONCE(RPC_IS_QUEUED(task)); |
811 | if (RPC_IS_QUEUED(task)) | |
812 | return; | |
1da177e4 | 813 | |
d05fdb0c | 814 | for (;;) { |
b55c5989 | 815 | void (*do_action)(struct rpc_task *); |
1da177e4 LT |
816 | |
817 | /* | |
21ead9ff CL |
818 | * Perform the next FSM step or a pending callback. |
819 | * | |
820 | * tk_action may be NULL if the task has been killed. | |
821 | * In particular, note that rpc_killall_tasks may | |
822 | * do this at any time, so beware when dereferencing. | |
1da177e4 | 823 | */ |
21ead9ff CL |
824 | do_action = task->tk_action; |
825 | if (task->tk_callback) { | |
826 | do_action = task->tk_callback; | |
827 | task->tk_callback = NULL; | |
1da177e4 | 828 | } |
21ead9ff CL |
829 | if (!do_action) |
830 | break; | |
e671edb9 | 831 | trace_rpc_task_run_action(task, do_action); |
b55c5989 | 832 | do_action(task); |
1da177e4 LT |
833 | |
834 | /* | |
835 | * Lockless check for whether task is sleeping or not. | |
836 | */ | |
837 | if (!RPC_IS_QUEUED(task)) | |
838 | continue; | |
eb9b55ab TM |
839 | /* |
840 | * The queue->lock protects against races with | |
841 | * rpc_make_runnable(). | |
842 | * | |
843 | * Note that once we clear RPC_TASK_RUNNING on an asynchronous | |
844 | * rpc_task, rpc_make_runnable() can assign it to a | |
845 | * different workqueue. We therefore cannot assume that the | |
846 | * rpc_task pointer may still be dereferenced. | |
847 | */ | |
848 | queue = task->tk_waitqueue; | |
849 | spin_lock_bh(&queue->lock); | |
850 | if (!RPC_IS_QUEUED(task)) { | |
851 | spin_unlock_bh(&queue->lock); | |
1da177e4 LT |
852 | continue; |
853 | } | |
eb9b55ab TM |
854 | rpc_clear_running(task); |
855 | spin_unlock_bh(&queue->lock); | |
856 | if (task_is_async) | |
857 | return; | |
1da177e4 LT |
858 | |
859 | /* sync task: sleep here */ | |
46121cf7 | 860 | dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid); |
96651ab3 | 861 | status = out_of_line_wait_on_bit(&task->tk_runstate, |
150030b7 MW |
862 | RPC_TASK_QUEUED, rpc_wait_bit_killable, |
863 | TASK_KILLABLE); | |
96651ab3 | 864 | if (status == -ERESTARTSYS) { |
1da177e4 LT |
865 | /* |
866 | * When a sync task receives a signal, it exits with | |
867 | * -ERESTARTSYS. In order to catch any callbacks that | |
868 | * clean up after sleeping on some queue, we don't | |
869 | * break the loop here, but go around once more. | |
870 | */ | |
46121cf7 | 871 | dprintk("RPC: %5u got signal\n", task->tk_pid); |
96651ab3 TM |
872 | task->tk_flags |= RPC_TASK_KILLED; |
873 | rpc_exit(task, -ERESTARTSYS); | |
1da177e4 | 874 | } |
46121cf7 | 875 | dprintk("RPC: %5u sync task resuming\n", task->tk_pid); |
1da177e4 LT |
876 | } |
877 | ||
46121cf7 CL |
878 | dprintk("RPC: %5u return %d, status %d\n", task->tk_pid, status, |
879 | task->tk_status); | |
1da177e4 LT |
880 | /* Release all resources associated with the task */ |
881 | rpc_release_task(task); | |
1da177e4 LT |
882 | } |
883 | ||
884 | /* | |
885 | * User-visible entry point to the scheduler. | |
886 | * | |
887 | * This may be called recursively if e.g. an async NFS task updates | |
888 | * the attributes and finds that dirty pages must be flushed. | |
889 | * NOTE: Upon exit of this function the task is guaranteed to be | |
890 | * released. In particular note that tk_release() will have | |
891 | * been called, so your task memory may have been freed. | |
892 | */ | |
2efef837 | 893 | void rpc_execute(struct rpc_task *task) |
1da177e4 | 894 | { |
a76580fb TM |
895 | bool is_async = RPC_IS_ASYNC(task); |
896 | ||
44c28873 | 897 | rpc_set_active(task); |
f1dc237c | 898 | rpc_make_runnable(rpciod_workqueue, task); |
a76580fb | 899 | if (!is_async) |
d6a1ed08 | 900 | __rpc_execute(task); |
1da177e4 LT |
901 | } |
902 | ||
65f27f38 | 903 | static void rpc_async_schedule(struct work_struct *work) |
1da177e4 | 904 | { |
a1231fda TM |
905 | unsigned int pflags = memalloc_nofs_save(); |
906 | ||
65f27f38 | 907 | __rpc_execute(container_of(work, struct rpc_task, u.tk_work)); |
a1231fda | 908 | memalloc_nofs_restore(pflags); |
1da177e4 LT |
909 | } |
910 | ||
02107148 | 911 | /** |
5fe6eaa1 CL |
912 | * rpc_malloc - allocate RPC buffer resources |
913 | * @task: RPC task | |
914 | * | |
915 | * A single memory region is allocated, which is split between the | |
916 | * RPC call and RPC reply that this task is being used for. When | |
917 | * this RPC is retired, the memory is released by calling rpc_free. | |
1da177e4 | 918 | * |
c5a4dd8b | 919 | * To prevent rpciod from hanging, this allocator never sleeps, |
5fe6eaa1 CL |
920 | * returning -ENOMEM and suppressing warning if the request cannot |
921 | * be serviced immediately. The caller can arrange to sleep in a | |
922 | * way that is safe for rpciod. | |
c5a4dd8b CL |
923 | * |
924 | * Most requests are 'small' (under 2KiB) and can be serviced from a | |
925 | * mempool, ensuring that NFS reads and writes can always proceed, | |
926 | * and that there is good locality of reference for these buffers. | |
1da177e4 | 927 | */ |
5fe6eaa1 | 928 | int rpc_malloc(struct rpc_task *task) |
1da177e4 | 929 | { |
5fe6eaa1 CL |
930 | struct rpc_rqst *rqst = task->tk_rqstp; |
931 | size_t size = rqst->rq_callsize + rqst->rq_rcvsize; | |
aa3d1fae | 932 | struct rpc_buffer *buf; |
12a3ad61 | 933 | gfp_t gfp = GFP_NOFS; |
a564b8f0 MG |
934 | |
935 | if (RPC_IS_SWAPPER(task)) | |
c4a7ca77 | 936 | gfp = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN; |
1da177e4 | 937 | |
aa3d1fae | 938 | size += sizeof(struct rpc_buffer); |
c5a4dd8b CL |
939 | if (size <= RPC_BUFFER_MAXSIZE) |
940 | buf = mempool_alloc(rpc_buffer_mempool, gfp); | |
1da177e4 | 941 | else |
c5a4dd8b | 942 | buf = kmalloc(size, gfp); |
ddce40df PZ |
943 | |
944 | if (!buf) | |
5fe6eaa1 | 945 | return -ENOMEM; |
ddce40df | 946 | |
aa3d1fae | 947 | buf->len = size; |
215d0678 | 948 | dprintk("RPC: %5u allocated buffer of size %zu at %p\n", |
c5a4dd8b | 949 | task->tk_pid, size, buf); |
5fe6eaa1 | 950 | rqst->rq_buffer = buf->data; |
68778945 | 951 | rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize; |
5fe6eaa1 | 952 | return 0; |
1da177e4 | 953 | } |
12444809 | 954 | EXPORT_SYMBOL_GPL(rpc_malloc); |
1da177e4 | 955 | |
02107148 | 956 | /** |
3435c74a CL |
957 | * rpc_free - free RPC buffer resources allocated via rpc_malloc |
958 | * @task: RPC task | |
02107148 CL |
959 | * |
960 | */ | |
3435c74a | 961 | void rpc_free(struct rpc_task *task) |
1da177e4 | 962 | { |
3435c74a | 963 | void *buffer = task->tk_rqstp->rq_buffer; |
aa3d1fae CL |
964 | size_t size; |
965 | struct rpc_buffer *buf; | |
02107148 | 966 | |
aa3d1fae CL |
967 | buf = container_of(buffer, struct rpc_buffer, data); |
968 | size = buf->len; | |
c5a4dd8b | 969 | |
215d0678 | 970 | dprintk("RPC: freeing buffer of size %zu at %p\n", |
c5a4dd8b | 971 | size, buf); |
aa3d1fae | 972 | |
c5a4dd8b CL |
973 | if (size <= RPC_BUFFER_MAXSIZE) |
974 | mempool_free(buf, rpc_buffer_mempool); | |
975 | else | |
976 | kfree(buf); | |
1da177e4 | 977 | } |
12444809 | 978 | EXPORT_SYMBOL_GPL(rpc_free); |
1da177e4 LT |
979 | |
980 | /* | |
981 | * Creation and deletion of RPC task structures | |
982 | */ | |
47fe0648 | 983 | static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data) |
1da177e4 LT |
984 | { |
985 | memset(task, 0, sizeof(*task)); | |
44c28873 | 986 | atomic_set(&task->tk_count, 1); |
84115e1c TM |
987 | task->tk_flags = task_setup_data->flags; |
988 | task->tk_ops = task_setup_data->callback_ops; | |
989 | task->tk_calldata = task_setup_data->callback_data; | |
6529eba0 | 990 | INIT_LIST_HEAD(&task->tk_task); |
1da177e4 | 991 | |
3ff7576d TM |
992 | task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW; |
993 | task->tk_owner = current->tgid; | |
1da177e4 LT |
994 | |
995 | /* Initialize workqueue for async tasks */ | |
32bfb5c0 | 996 | task->tk_workqueue = task_setup_data->workqueue; |
1da177e4 | 997 | |
9d61498d TM |
998 | task->tk_xprt = xprt_get(task_setup_data->rpc_xprt); |
999 | ||
1de7eea9 N |
1000 | task->tk_op_cred = get_rpccred(task_setup_data->rpc_op_cred); |
1001 | ||
84115e1c TM |
1002 | if (task->tk_ops->rpc_call_prepare != NULL) |
1003 | task->tk_action = rpc_prepare_task; | |
963d8fe5 | 1004 | |
7fdcf13b | 1005 | rpc_init_task_statistics(task); |
ef759a2e | 1006 | |
46121cf7 | 1007 | dprintk("RPC: new task initialized, procpid %u\n", |
ba25f9dc | 1008 | task_pid_nr(current)); |
1da177e4 LT |
1009 | } |
1010 | ||
1011 | static struct rpc_task * | |
1012 | rpc_alloc_task(void) | |
1013 | { | |
12a3ad61 | 1014 | return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS); |
1da177e4 LT |
1015 | } |
1016 | ||
1da177e4 | 1017 | /* |
90c5755f | 1018 | * Create a new task for the specified client. |
1da177e4 | 1019 | */ |
84115e1c | 1020 | struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data) |
1da177e4 | 1021 | { |
e8f5d77c TM |
1022 | struct rpc_task *task = setup_data->task; |
1023 | unsigned short flags = 0; | |
1024 | ||
1025 | if (task == NULL) { | |
1026 | task = rpc_alloc_task(); | |
e8f5d77c TM |
1027 | flags = RPC_TASK_DYNAMIC; |
1028 | } | |
1da177e4 | 1029 | |
84115e1c | 1030 | rpc_init_task(task, setup_data); |
e8f5d77c | 1031 | task->tk_flags |= flags; |
46121cf7 | 1032 | dprintk("RPC: allocated task %p\n", task); |
1da177e4 | 1033 | return task; |
1da177e4 LT |
1034 | } |
1035 | ||
c6567ed1 TM |
1036 | /* |
1037 | * rpc_free_task - release rpc task and perform cleanups | |
1038 | * | |
1039 | * Note that we free up the rpc_task _after_ rpc_release_calldata() | |
1040 | * in order to work around a workqueue dependency issue. | |
1041 | * | |
1042 | * Tejun Heo states: | |
1043 | * "Workqueue currently considers two work items to be the same if they're | |
1044 | * on the same address and won't execute them concurrently - ie. it | |
1045 | * makes a work item which is queued again while being executed wait | |
1046 | * for the previous execution to complete. | |
1047 | * | |
1048 | * If a work function frees the work item, and then waits for an event | |
1049 | * which should be performed by another work item and *that* work item | |
1050 | * recycles the freed work item, it can create a false dependency loop. | |
1051 | * There really is no reliable way to detect this short of verifying | |
1052 | * every memory free." | |
1053 | * | |
1054 | */ | |
32bfb5c0 | 1055 | static void rpc_free_task(struct rpc_task *task) |
1da177e4 | 1056 | { |
c6567ed1 TM |
1057 | unsigned short tk_flags = task->tk_flags; |
1058 | ||
1de7eea9 | 1059 | put_rpccred(task->tk_op_cred); |
c6567ed1 | 1060 | rpc_release_calldata(task->tk_ops, task->tk_calldata); |
1da177e4 | 1061 | |
c6567ed1 | 1062 | if (tk_flags & RPC_TASK_DYNAMIC) { |
5e4424af TM |
1063 | dprintk("RPC: %5u freeing task\n", task->tk_pid); |
1064 | mempool_free(task, rpc_task_mempool); | |
1065 | } | |
32bfb5c0 TM |
1066 | } |
1067 | ||
1068 | static void rpc_async_release(struct work_struct *work) | |
1069 | { | |
a1231fda TM |
1070 | unsigned int pflags = memalloc_nofs_save(); |
1071 | ||
32bfb5c0 | 1072 | rpc_free_task(container_of(work, struct rpc_task, u.tk_work)); |
a1231fda | 1073 | memalloc_nofs_restore(pflags); |
32bfb5c0 TM |
1074 | } |
1075 | ||
bf294b41 | 1076 | static void rpc_release_resources_task(struct rpc_task *task) |
32bfb5c0 | 1077 | { |
87ed5003 | 1078 | xprt_release(task); |
a271c5a0 | 1079 | if (task->tk_msg.rpc_cred) { |
a52458b4 | 1080 | put_cred(task->tk_msg.rpc_cred); |
a271c5a0 OH |
1081 | task->tk_msg.rpc_cred = NULL; |
1082 | } | |
58f9612c | 1083 | rpc_task_release_client(task); |
bf294b41 TM |
1084 | } |
1085 | ||
1086 | static void rpc_final_put_task(struct rpc_task *task, | |
1087 | struct workqueue_struct *q) | |
1088 | { | |
1089 | if (q != NULL) { | |
32bfb5c0 | 1090 | INIT_WORK(&task->u.tk_work, rpc_async_release); |
bf294b41 | 1091 | queue_work(q, &task->u.tk_work); |
32bfb5c0 TM |
1092 | } else |
1093 | rpc_free_task(task); | |
e6b3c4db | 1094 | } |
bf294b41 TM |
1095 | |
1096 | static void rpc_do_put_task(struct rpc_task *task, struct workqueue_struct *q) | |
1097 | { | |
1098 | if (atomic_dec_and_test(&task->tk_count)) { | |
1099 | rpc_release_resources_task(task); | |
1100 | rpc_final_put_task(task, q); | |
1101 | } | |
1102 | } | |
1103 | ||
1104 | void rpc_put_task(struct rpc_task *task) | |
1105 | { | |
1106 | rpc_do_put_task(task, NULL); | |
1107 | } | |
e8914c65 | 1108 | EXPORT_SYMBOL_GPL(rpc_put_task); |
e6b3c4db | 1109 | |
bf294b41 TM |
1110 | void rpc_put_task_async(struct rpc_task *task) |
1111 | { | |
1112 | rpc_do_put_task(task, task->tk_workqueue); | |
1113 | } | |
1114 | EXPORT_SYMBOL_GPL(rpc_put_task_async); | |
1115 | ||
bde8f00c | 1116 | static void rpc_release_task(struct rpc_task *task) |
e6b3c4db | 1117 | { |
46121cf7 | 1118 | dprintk("RPC: %5u release task\n", task->tk_pid); |
1da177e4 | 1119 | |
0a0c2a57 | 1120 | WARN_ON_ONCE(RPC_IS_QUEUED(task)); |
1da177e4 | 1121 | |
bf294b41 | 1122 | rpc_release_resources_task(task); |
e6b3c4db | 1123 | |
bf294b41 TM |
1124 | /* |
1125 | * Note: at this point we have been removed from rpc_clnt->cl_tasks, | |
1126 | * so it should be safe to use task->tk_count as a test for whether | |
1127 | * or not any other processes still hold references to our rpc_task. | |
1128 | */ | |
1129 | if (atomic_read(&task->tk_count) != 1 + !RPC_IS_ASYNC(task)) { | |
1130 | /* Wake up anyone who may be waiting for task completion */ | |
1131 | if (!rpc_complete_task(task)) | |
1132 | return; | |
1133 | } else { | |
1134 | if (!atomic_dec_and_test(&task->tk_count)) | |
1135 | return; | |
1136 | } | |
1137 | rpc_final_put_task(task, task->tk_workqueue); | |
1da177e4 LT |
1138 | } |
1139 | ||
b247bbf1 TM |
1140 | int rpciod_up(void) |
1141 | { | |
1142 | return try_module_get(THIS_MODULE) ? 0 : -EINVAL; | |
1143 | } | |
1144 | ||
1145 | void rpciod_down(void) | |
1146 | { | |
1147 | module_put(THIS_MODULE); | |
1148 | } | |
1149 | ||
1da177e4 | 1150 | /* |
b247bbf1 | 1151 | * Start up the rpciod workqueue. |
1da177e4 | 1152 | */ |
b247bbf1 | 1153 | static int rpciod_start(void) |
1da177e4 LT |
1154 | { |
1155 | struct workqueue_struct *wq; | |
ab418d70 | 1156 | |
1da177e4 LT |
1157 | /* |
1158 | * Create the rpciod thread and wait for it to start. | |
1159 | */ | |
ab418d70 | 1160 | dprintk("RPC: creating workqueue rpciod\n"); |
f515f86b | 1161 | wq = alloc_workqueue("rpciod", WQ_MEM_RECLAIM | WQ_UNBOUND, 0); |
40a5f1b1 TM |
1162 | if (!wq) |
1163 | goto out_failed; | |
1da177e4 | 1164 | rpciod_workqueue = wq; |
40a5f1b1 | 1165 | /* Note: highpri because network receive is latency sensitive */ |
90ea9f1b | 1166 | wq = alloc_workqueue("xprtiod", WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_HIGHPRI, 0); |
40a5f1b1 TM |
1167 | if (!wq) |
1168 | goto free_rpciod; | |
1169 | xprtiod_workqueue = wq; | |
1170 | return 1; | |
1171 | free_rpciod: | |
1172 | wq = rpciod_workqueue; | |
1173 | rpciod_workqueue = NULL; | |
1174 | destroy_workqueue(wq); | |
1175 | out_failed: | |
1176 | return 0; | |
1da177e4 LT |
1177 | } |
1178 | ||
b247bbf1 | 1179 | static void rpciod_stop(void) |
1da177e4 | 1180 | { |
b247bbf1 | 1181 | struct workqueue_struct *wq = NULL; |
ab418d70 | 1182 | |
b247bbf1 TM |
1183 | if (rpciod_workqueue == NULL) |
1184 | return; | |
ab418d70 | 1185 | dprintk("RPC: destroying workqueue rpciod\n"); |
1da177e4 | 1186 | |
b247bbf1 TM |
1187 | wq = rpciod_workqueue; |
1188 | rpciod_workqueue = NULL; | |
1189 | destroy_workqueue(wq); | |
40a5f1b1 TM |
1190 | wq = xprtiod_workqueue; |
1191 | xprtiod_workqueue = NULL; | |
1192 | destroy_workqueue(wq); | |
1da177e4 LT |
1193 | } |
1194 | ||
1da177e4 LT |
1195 | void |
1196 | rpc_destroy_mempool(void) | |
1197 | { | |
b247bbf1 | 1198 | rpciod_stop(); |
17a9618e JL |
1199 | mempool_destroy(rpc_buffer_mempool); |
1200 | mempool_destroy(rpc_task_mempool); | |
1201 | kmem_cache_destroy(rpc_task_slabp); | |
1202 | kmem_cache_destroy(rpc_buffer_slabp); | |
f6a1cc89 | 1203 | rpc_destroy_wait_queue(&delay_queue); |
1da177e4 LT |
1204 | } |
1205 | ||
1206 | int | |
1207 | rpc_init_mempool(void) | |
1208 | { | |
f6a1cc89 TM |
1209 | /* |
1210 | * The following is not strictly a mempool initialisation, | |
1211 | * but there is no harm in doing it here | |
1212 | */ | |
1213 | rpc_init_wait_queue(&delay_queue, "delayq"); | |
1214 | if (!rpciod_start()) | |
1215 | goto err_nomem; | |
1216 | ||
1da177e4 LT |
1217 | rpc_task_slabp = kmem_cache_create("rpc_tasks", |
1218 | sizeof(struct rpc_task), | |
1219 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1220 | NULL); |
1da177e4 LT |
1221 | if (!rpc_task_slabp) |
1222 | goto err_nomem; | |
1223 | rpc_buffer_slabp = kmem_cache_create("rpc_buffers", | |
1224 | RPC_BUFFER_MAXSIZE, | |
1225 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1226 | NULL); |
1da177e4 LT |
1227 | if (!rpc_buffer_slabp) |
1228 | goto err_nomem; | |
93d2341c MD |
1229 | rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE, |
1230 | rpc_task_slabp); | |
1da177e4 LT |
1231 | if (!rpc_task_mempool) |
1232 | goto err_nomem; | |
93d2341c MD |
1233 | rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE, |
1234 | rpc_buffer_slabp); | |
1da177e4 LT |
1235 | if (!rpc_buffer_mempool) |
1236 | goto err_nomem; | |
1237 | return 0; | |
1238 | err_nomem: | |
1239 | rpc_destroy_mempool(); | |
1240 | return -ENOMEM; | |
1241 | } |