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1 | /* | |
2 | * QEMU posix-aio emulation | |
3 | * | |
4 | * Copyright IBM, Corp. 2008 | |
5 | * | |
6 | * Authors: | |
7 | * Anthony Liguori <aliguori@us.ibm.com> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
10 | * the COPYING file in the top-level directory. | |
11 | * | |
12 | * Contributions after 2012-01-13 are licensed under the terms of the | |
13 | * GNU GPL, version 2 or (at your option) any later version. | |
14 | */ | |
15 | ||
16 | #include <sys/ioctl.h> | |
17 | #include <sys/types.h> | |
18 | #include <pthread.h> | |
19 | #include <unistd.h> | |
20 | #include <errno.h> | |
21 | #include <time.h> | |
22 | #include <string.h> | |
23 | #include <stdlib.h> | |
24 | #include <stdio.h> | |
25 | ||
26 | #include "qemu-queue.h" | |
27 | #include "osdep.h" | |
28 | #include "sysemu.h" | |
29 | #include "qemu-common.h" | |
30 | #include "trace.h" | |
31 | #include "block_int.h" | |
32 | ||
33 | #include "block/raw-posix-aio.h" | |
34 | ||
35 | static void do_spawn_thread(void); | |
36 | ||
37 | struct qemu_paiocb { | |
38 | BlockDriverAIOCB common; | |
39 | int aio_fildes; | |
40 | union { | |
41 | struct iovec *aio_iov; | |
42 | void *aio_ioctl_buf; | |
43 | }; | |
44 | int aio_niov; | |
45 | size_t aio_nbytes; | |
46 | #define aio_ioctl_cmd aio_nbytes /* for QEMU_AIO_IOCTL */ | |
47 | off_t aio_offset; | |
48 | ||
49 | QTAILQ_ENTRY(qemu_paiocb) node; | |
50 | int aio_type; | |
51 | ssize_t ret; | |
52 | int active; | |
53 | struct qemu_paiocb *next; | |
54 | }; | |
55 | ||
56 | typedef struct PosixAioState { | |
57 | int rfd, wfd; | |
58 | struct qemu_paiocb *first_aio; | |
59 | } PosixAioState; | |
60 | ||
61 | ||
62 | static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; | |
63 | static pthread_cond_t cond = PTHREAD_COND_INITIALIZER; | |
64 | static pthread_t thread_id; | |
65 | static pthread_attr_t attr; | |
66 | static int max_threads = 64; | |
67 | static int cur_threads = 0; | |
68 | static int idle_threads = 0; | |
69 | static int new_threads = 0; /* backlog of threads we need to create */ | |
70 | static int pending_threads = 0; /* threads created but not running yet */ | |
71 | static QEMUBH *new_thread_bh; | |
72 | static QTAILQ_HEAD(, qemu_paiocb) request_list; | |
73 | ||
74 | #ifdef CONFIG_PREADV | |
75 | static int preadv_present = 1; | |
76 | #else | |
77 | static int preadv_present = 0; | |
78 | #endif | |
79 | ||
80 | static void die2(int err, const char *what) | |
81 | { | |
82 | fprintf(stderr, "%s failed: %s\n", what, strerror(err)); | |
83 | abort(); | |
84 | } | |
85 | ||
86 | static void die(const char *what) | |
87 | { | |
88 | die2(errno, what); | |
89 | } | |
90 | ||
91 | static void mutex_lock(pthread_mutex_t *mutex) | |
92 | { | |
93 | int ret = pthread_mutex_lock(mutex); | |
94 | if (ret) die2(ret, "pthread_mutex_lock"); | |
95 | } | |
96 | ||
97 | static void mutex_unlock(pthread_mutex_t *mutex) | |
98 | { | |
99 | int ret = pthread_mutex_unlock(mutex); | |
100 | if (ret) die2(ret, "pthread_mutex_unlock"); | |
101 | } | |
102 | ||
103 | static int cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, | |
104 | struct timespec *ts) | |
105 | { | |
106 | int ret = pthread_cond_timedwait(cond, mutex, ts); | |
107 | if (ret && ret != ETIMEDOUT) die2(ret, "pthread_cond_timedwait"); | |
108 | return ret; | |
109 | } | |
110 | ||
111 | static void cond_signal(pthread_cond_t *cond) | |
112 | { | |
113 | int ret = pthread_cond_signal(cond); | |
114 | if (ret) die2(ret, "pthread_cond_signal"); | |
115 | } | |
116 | ||
117 | static void thread_create(pthread_t *thread, pthread_attr_t *attr, | |
118 | void *(*start_routine)(void*), void *arg) | |
119 | { | |
120 | int ret = pthread_create(thread, attr, start_routine, arg); | |
121 | if (ret) die2(ret, "pthread_create"); | |
122 | } | |
123 | ||
124 | static ssize_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb) | |
125 | { | |
126 | int ret; | |
127 | ||
128 | ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_ioctl_buf); | |
129 | if (ret == -1) | |
130 | return -errno; | |
131 | ||
132 | /* | |
133 | * This looks weird, but the aio code only considers a request | |
134 | * successful if it has written the full number of bytes. | |
135 | * | |
136 | * Now we overload aio_nbytes as aio_ioctl_cmd for the ioctl command, | |
137 | * so in fact we return the ioctl command here to make posix_aio_read() | |
138 | * happy.. | |
139 | */ | |
140 | return aiocb->aio_nbytes; | |
141 | } | |
142 | ||
143 | static ssize_t handle_aiocb_flush(struct qemu_paiocb *aiocb) | |
144 | { | |
145 | int ret; | |
146 | ||
147 | ret = qemu_fdatasync(aiocb->aio_fildes); | |
148 | if (ret == -1) | |
149 | return -errno; | |
150 | return 0; | |
151 | } | |
152 | ||
153 | #ifdef CONFIG_PREADV | |
154 | ||
155 | static ssize_t | |
156 | qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset) | |
157 | { | |
158 | return preadv(fd, iov, nr_iov, offset); | |
159 | } | |
160 | ||
161 | static ssize_t | |
162 | qemu_pwritev(int fd, const struct iovec *iov, int nr_iov, off_t offset) | |
163 | { | |
164 | return pwritev(fd, iov, nr_iov, offset); | |
165 | } | |
166 | ||
167 | #else | |
168 | ||
169 | static ssize_t | |
170 | qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset) | |
171 | { | |
172 | return -ENOSYS; | |
173 | } | |
174 | ||
175 | static ssize_t | |
176 | qemu_pwritev(int fd, const struct iovec *iov, int nr_iov, off_t offset) | |
177 | { | |
178 | return -ENOSYS; | |
179 | } | |
180 | ||
181 | #endif | |
182 | ||
183 | static ssize_t handle_aiocb_rw_vector(struct qemu_paiocb *aiocb) | |
184 | { | |
185 | ssize_t len; | |
186 | ||
187 | do { | |
188 | if (aiocb->aio_type & QEMU_AIO_WRITE) | |
189 | len = qemu_pwritev(aiocb->aio_fildes, | |
190 | aiocb->aio_iov, | |
191 | aiocb->aio_niov, | |
192 | aiocb->aio_offset); | |
193 | else | |
194 | len = qemu_preadv(aiocb->aio_fildes, | |
195 | aiocb->aio_iov, | |
196 | aiocb->aio_niov, | |
197 | aiocb->aio_offset); | |
198 | } while (len == -1 && errno == EINTR); | |
199 | ||
200 | if (len == -1) | |
201 | return -errno; | |
202 | return len; | |
203 | } | |
204 | ||
205 | /* | |
206 | * Read/writes the data to/from a given linear buffer. | |
207 | * | |
208 | * Returns the number of bytes handles or -errno in case of an error. Short | |
209 | * reads are only returned if the end of the file is reached. | |
210 | */ | |
211 | static ssize_t handle_aiocb_rw_linear(struct qemu_paiocb *aiocb, char *buf) | |
212 | { | |
213 | ssize_t offset = 0; | |
214 | ssize_t len; | |
215 | ||
216 | while (offset < aiocb->aio_nbytes) { | |
217 | if (aiocb->aio_type & QEMU_AIO_WRITE) | |
218 | len = pwrite(aiocb->aio_fildes, | |
219 | (const char *)buf + offset, | |
220 | aiocb->aio_nbytes - offset, | |
221 | aiocb->aio_offset + offset); | |
222 | else | |
223 | len = pread(aiocb->aio_fildes, | |
224 | buf + offset, | |
225 | aiocb->aio_nbytes - offset, | |
226 | aiocb->aio_offset + offset); | |
227 | ||
228 | if (len == -1 && errno == EINTR) | |
229 | continue; | |
230 | else if (len == -1) { | |
231 | offset = -errno; | |
232 | break; | |
233 | } else if (len == 0) | |
234 | break; | |
235 | ||
236 | offset += len; | |
237 | } | |
238 | ||
239 | return offset; | |
240 | } | |
241 | ||
242 | static ssize_t handle_aiocb_rw(struct qemu_paiocb *aiocb) | |
243 | { | |
244 | ssize_t nbytes; | |
245 | char *buf; | |
246 | ||
247 | if (!(aiocb->aio_type & QEMU_AIO_MISALIGNED)) { | |
248 | /* | |
249 | * If there is just a single buffer, and it is properly aligned | |
250 | * we can just use plain pread/pwrite without any problems. | |
251 | */ | |
252 | if (aiocb->aio_niov == 1) | |
253 | return handle_aiocb_rw_linear(aiocb, aiocb->aio_iov->iov_base); | |
254 | ||
255 | /* | |
256 | * We have more than one iovec, and all are properly aligned. | |
257 | * | |
258 | * Try preadv/pwritev first and fall back to linearizing the | |
259 | * buffer if it's not supported. | |
260 | */ | |
261 | if (preadv_present) { | |
262 | nbytes = handle_aiocb_rw_vector(aiocb); | |
263 | if (nbytes == aiocb->aio_nbytes) | |
264 | return nbytes; | |
265 | if (nbytes < 0 && nbytes != -ENOSYS) | |
266 | return nbytes; | |
267 | preadv_present = 0; | |
268 | } | |
269 | ||
270 | /* | |
271 | * XXX(hch): short read/write. no easy way to handle the reminder | |
272 | * using these interfaces. For now retry using plain | |
273 | * pread/pwrite? | |
274 | */ | |
275 | } | |
276 | ||
277 | /* | |
278 | * Ok, we have to do it the hard way, copy all segments into | |
279 | * a single aligned buffer. | |
280 | */ | |
281 | buf = qemu_blockalign(aiocb->common.bs, aiocb->aio_nbytes); | |
282 | if (aiocb->aio_type & QEMU_AIO_WRITE) { | |
283 | char *p = buf; | |
284 | int i; | |
285 | ||
286 | for (i = 0; i < aiocb->aio_niov; ++i) { | |
287 | memcpy(p, aiocb->aio_iov[i].iov_base, aiocb->aio_iov[i].iov_len); | |
288 | p += aiocb->aio_iov[i].iov_len; | |
289 | } | |
290 | } | |
291 | ||
292 | nbytes = handle_aiocb_rw_linear(aiocb, buf); | |
293 | if (!(aiocb->aio_type & QEMU_AIO_WRITE)) { | |
294 | char *p = buf; | |
295 | size_t count = aiocb->aio_nbytes, copy; | |
296 | int i; | |
297 | ||
298 | for (i = 0; i < aiocb->aio_niov && count; ++i) { | |
299 | copy = count; | |
300 | if (copy > aiocb->aio_iov[i].iov_len) | |
301 | copy = aiocb->aio_iov[i].iov_len; | |
302 | memcpy(aiocb->aio_iov[i].iov_base, p, copy); | |
303 | p += copy; | |
304 | count -= copy; | |
305 | } | |
306 | } | |
307 | qemu_vfree(buf); | |
308 | ||
309 | return nbytes; | |
310 | } | |
311 | ||
312 | static void posix_aio_notify_event(void); | |
313 | ||
314 | static void *aio_thread(void *unused) | |
315 | { | |
316 | mutex_lock(&lock); | |
317 | pending_threads--; | |
318 | mutex_unlock(&lock); | |
319 | do_spawn_thread(); | |
320 | ||
321 | while (1) { | |
322 | struct qemu_paiocb *aiocb; | |
323 | ssize_t ret = 0; | |
324 | qemu_timeval tv; | |
325 | struct timespec ts; | |
326 | ||
327 | qemu_gettimeofday(&tv); | |
328 | ts.tv_sec = tv.tv_sec + 10; | |
329 | ts.tv_nsec = 0; | |
330 | ||
331 | mutex_lock(&lock); | |
332 | ||
333 | while (QTAILQ_EMPTY(&request_list) && | |
334 | !(ret == ETIMEDOUT)) { | |
335 | idle_threads++; | |
336 | ret = cond_timedwait(&cond, &lock, &ts); | |
337 | idle_threads--; | |
338 | } | |
339 | ||
340 | if (QTAILQ_EMPTY(&request_list)) | |
341 | break; | |
342 | ||
343 | aiocb = QTAILQ_FIRST(&request_list); | |
344 | QTAILQ_REMOVE(&request_list, aiocb, node); | |
345 | aiocb->active = 1; | |
346 | mutex_unlock(&lock); | |
347 | ||
348 | switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) { | |
349 | case QEMU_AIO_READ: | |
350 | ret = handle_aiocb_rw(aiocb); | |
351 | if (ret >= 0 && ret < aiocb->aio_nbytes && aiocb->common.bs->growable) { | |
352 | /* A short read means that we have reached EOF. Pad the buffer | |
353 | * with zeros for bytes after EOF. */ | |
354 | QEMUIOVector qiov; | |
355 | ||
356 | qemu_iovec_init_external(&qiov, aiocb->aio_iov, | |
357 | aiocb->aio_niov); | |
358 | qemu_iovec_memset_skip(&qiov, 0, aiocb->aio_nbytes - ret, ret); | |
359 | ||
360 | ret = aiocb->aio_nbytes; | |
361 | } | |
362 | break; | |
363 | case QEMU_AIO_WRITE: | |
364 | ret = handle_aiocb_rw(aiocb); | |
365 | break; | |
366 | case QEMU_AIO_FLUSH: | |
367 | ret = handle_aiocb_flush(aiocb); | |
368 | break; | |
369 | case QEMU_AIO_IOCTL: | |
370 | ret = handle_aiocb_ioctl(aiocb); | |
371 | break; | |
372 | default: | |
373 | fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type); | |
374 | ret = -EINVAL; | |
375 | break; | |
376 | } | |
377 | ||
378 | mutex_lock(&lock); | |
379 | aiocb->ret = ret; | |
380 | mutex_unlock(&lock); | |
381 | ||
382 | posix_aio_notify_event(); | |
383 | } | |
384 | ||
385 | cur_threads--; | |
386 | mutex_unlock(&lock); | |
387 | ||
388 | return NULL; | |
389 | } | |
390 | ||
391 | static void do_spawn_thread(void) | |
392 | { | |
393 | sigset_t set, oldset; | |
394 | ||
395 | mutex_lock(&lock); | |
396 | if (!new_threads) { | |
397 | mutex_unlock(&lock); | |
398 | return; | |
399 | } | |
400 | ||
401 | new_threads--; | |
402 | pending_threads++; | |
403 | ||
404 | mutex_unlock(&lock); | |
405 | ||
406 | /* block all signals */ | |
407 | if (sigfillset(&set)) die("sigfillset"); | |
408 | if (sigprocmask(SIG_SETMASK, &set, &oldset)) die("sigprocmask"); | |
409 | ||
410 | thread_create(&thread_id, &attr, aio_thread, NULL); | |
411 | ||
412 | if (sigprocmask(SIG_SETMASK, &oldset, NULL)) die("sigprocmask restore"); | |
413 | } | |
414 | ||
415 | static void spawn_thread_bh_fn(void *opaque) | |
416 | { | |
417 | do_spawn_thread(); | |
418 | } | |
419 | ||
420 | static void spawn_thread(void) | |
421 | { | |
422 | cur_threads++; | |
423 | new_threads++; | |
424 | /* If there are threads being created, they will spawn new workers, so | |
425 | * we don't spend time creating many threads in a loop holding a mutex or | |
426 | * starving the current vcpu. | |
427 | * | |
428 | * If there are no idle threads, ask the main thread to create one, so we | |
429 | * inherit the correct affinity instead of the vcpu affinity. | |
430 | */ | |
431 | if (!pending_threads) { | |
432 | qemu_bh_schedule(new_thread_bh); | |
433 | } | |
434 | } | |
435 | ||
436 | static void qemu_paio_submit(struct qemu_paiocb *aiocb) | |
437 | { | |
438 | aiocb->ret = -EINPROGRESS; | |
439 | aiocb->active = 0; | |
440 | mutex_lock(&lock); | |
441 | if (idle_threads == 0 && cur_threads < max_threads) | |
442 | spawn_thread(); | |
443 | QTAILQ_INSERT_TAIL(&request_list, aiocb, node); | |
444 | mutex_unlock(&lock); | |
445 | cond_signal(&cond); | |
446 | } | |
447 | ||
448 | static ssize_t qemu_paio_return(struct qemu_paiocb *aiocb) | |
449 | { | |
450 | ssize_t ret; | |
451 | ||
452 | mutex_lock(&lock); | |
453 | ret = aiocb->ret; | |
454 | mutex_unlock(&lock); | |
455 | ||
456 | return ret; | |
457 | } | |
458 | ||
459 | static int qemu_paio_error(struct qemu_paiocb *aiocb) | |
460 | { | |
461 | ssize_t ret = qemu_paio_return(aiocb); | |
462 | ||
463 | if (ret < 0) | |
464 | ret = -ret; | |
465 | else | |
466 | ret = 0; | |
467 | ||
468 | return ret; | |
469 | } | |
470 | ||
471 | static int posix_aio_process_queue(void *opaque) | |
472 | { | |
473 | PosixAioState *s = opaque; | |
474 | struct qemu_paiocb *acb, **pacb; | |
475 | int ret; | |
476 | int result = 0; | |
477 | ||
478 | for(;;) { | |
479 | pacb = &s->first_aio; | |
480 | for(;;) { | |
481 | acb = *pacb; | |
482 | if (!acb) | |
483 | return result; | |
484 | ||
485 | ret = qemu_paio_error(acb); | |
486 | if (ret == ECANCELED) { | |
487 | /* remove the request */ | |
488 | *pacb = acb->next; | |
489 | qemu_aio_release(acb); | |
490 | result = 1; | |
491 | } else if (ret != EINPROGRESS) { | |
492 | /* end of aio */ | |
493 | if (ret == 0) { | |
494 | ret = qemu_paio_return(acb); | |
495 | if (ret == acb->aio_nbytes) | |
496 | ret = 0; | |
497 | else | |
498 | ret = -EINVAL; | |
499 | } else { | |
500 | ret = -ret; | |
501 | } | |
502 | ||
503 | trace_paio_complete(acb, acb->common.opaque, ret); | |
504 | ||
505 | /* remove the request */ | |
506 | *pacb = acb->next; | |
507 | /* call the callback */ | |
508 | acb->common.cb(acb->common.opaque, ret); | |
509 | qemu_aio_release(acb); | |
510 | result = 1; | |
511 | break; | |
512 | } else { | |
513 | pacb = &acb->next; | |
514 | } | |
515 | } | |
516 | } | |
517 | ||
518 | return result; | |
519 | } | |
520 | ||
521 | static void posix_aio_read(void *opaque) | |
522 | { | |
523 | PosixAioState *s = opaque; | |
524 | ssize_t len; | |
525 | ||
526 | /* read all bytes from signal pipe */ | |
527 | for (;;) { | |
528 | char bytes[16]; | |
529 | ||
530 | len = read(s->rfd, bytes, sizeof(bytes)); | |
531 | if (len == -1 && errno == EINTR) | |
532 | continue; /* try again */ | |
533 | if (len == sizeof(bytes)) | |
534 | continue; /* more to read */ | |
535 | break; | |
536 | } | |
537 | ||
538 | posix_aio_process_queue(s); | |
539 | } | |
540 | ||
541 | static int posix_aio_flush(void *opaque) | |
542 | { | |
543 | PosixAioState *s = opaque; | |
544 | return !!s->first_aio; | |
545 | } | |
546 | ||
547 | static PosixAioState *posix_aio_state; | |
548 | ||
549 | static void posix_aio_notify_event(void) | |
550 | { | |
551 | char byte = 0; | |
552 | ssize_t ret; | |
553 | ||
554 | ret = write(posix_aio_state->wfd, &byte, sizeof(byte)); | |
555 | if (ret < 0 && errno != EAGAIN) | |
556 | die("write()"); | |
557 | } | |
558 | ||
559 | static void paio_remove(struct qemu_paiocb *acb) | |
560 | { | |
561 | struct qemu_paiocb **pacb; | |
562 | ||
563 | /* remove the callback from the queue */ | |
564 | pacb = &posix_aio_state->first_aio; | |
565 | for(;;) { | |
566 | if (*pacb == NULL) { | |
567 | fprintf(stderr, "paio_remove: aio request not found!\n"); | |
568 | break; | |
569 | } else if (*pacb == acb) { | |
570 | *pacb = acb->next; | |
571 | qemu_aio_release(acb); | |
572 | break; | |
573 | } | |
574 | pacb = &(*pacb)->next; | |
575 | } | |
576 | } | |
577 | ||
578 | static void paio_cancel(BlockDriverAIOCB *blockacb) | |
579 | { | |
580 | struct qemu_paiocb *acb = (struct qemu_paiocb *)blockacb; | |
581 | int active = 0; | |
582 | ||
583 | trace_paio_cancel(acb, acb->common.opaque); | |
584 | ||
585 | mutex_lock(&lock); | |
586 | if (!acb->active) { | |
587 | QTAILQ_REMOVE(&request_list, acb, node); | |
588 | acb->ret = -ECANCELED; | |
589 | } else if (acb->ret == -EINPROGRESS) { | |
590 | active = 1; | |
591 | } | |
592 | mutex_unlock(&lock); | |
593 | ||
594 | if (active) { | |
595 | /* fail safe: if the aio could not be canceled, we wait for | |
596 | it */ | |
597 | while (qemu_paio_error(acb) == EINPROGRESS) | |
598 | ; | |
599 | } | |
600 | ||
601 | paio_remove(acb); | |
602 | } | |
603 | ||
604 | static AIOPool raw_aio_pool = { | |
605 | .aiocb_size = sizeof(struct qemu_paiocb), | |
606 | .cancel = paio_cancel, | |
607 | }; | |
608 | ||
609 | BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd, | |
610 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
611 | BlockDriverCompletionFunc *cb, void *opaque, int type) | |
612 | { | |
613 | struct qemu_paiocb *acb; | |
614 | ||
615 | acb = qemu_aio_get(&raw_aio_pool, bs, cb, opaque); | |
616 | acb->aio_type = type; | |
617 | acb->aio_fildes = fd; | |
618 | ||
619 | if (qiov) { | |
620 | acb->aio_iov = qiov->iov; | |
621 | acb->aio_niov = qiov->niov; | |
622 | } | |
623 | acb->aio_nbytes = nb_sectors * 512; | |
624 | acb->aio_offset = sector_num * 512; | |
625 | ||
626 | acb->next = posix_aio_state->first_aio; | |
627 | posix_aio_state->first_aio = acb; | |
628 | ||
629 | trace_paio_submit(acb, opaque, sector_num, nb_sectors, type); | |
630 | qemu_paio_submit(acb); | |
631 | return &acb->common; | |
632 | } | |
633 | ||
634 | BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd, | |
635 | unsigned long int req, void *buf, | |
636 | BlockDriverCompletionFunc *cb, void *opaque) | |
637 | { | |
638 | struct qemu_paiocb *acb; | |
639 | ||
640 | acb = qemu_aio_get(&raw_aio_pool, bs, cb, opaque); | |
641 | acb->aio_type = QEMU_AIO_IOCTL; | |
642 | acb->aio_fildes = fd; | |
643 | acb->aio_offset = 0; | |
644 | acb->aio_ioctl_buf = buf; | |
645 | acb->aio_ioctl_cmd = req; | |
646 | ||
647 | acb->next = posix_aio_state->first_aio; | |
648 | posix_aio_state->first_aio = acb; | |
649 | ||
650 | qemu_paio_submit(acb); | |
651 | return &acb->common; | |
652 | } | |
653 | ||
654 | int paio_init(void) | |
655 | { | |
656 | PosixAioState *s; | |
657 | int fds[2]; | |
658 | int ret; | |
659 | ||
660 | if (posix_aio_state) | |
661 | return 0; | |
662 | ||
663 | s = g_malloc(sizeof(PosixAioState)); | |
664 | ||
665 | s->first_aio = NULL; | |
666 | if (qemu_pipe(fds) == -1) { | |
667 | fprintf(stderr, "failed to create pipe\n"); | |
668 | g_free(s); | |
669 | return -1; | |
670 | } | |
671 | ||
672 | s->rfd = fds[0]; | |
673 | s->wfd = fds[1]; | |
674 | ||
675 | fcntl(s->rfd, F_SETFL, O_NONBLOCK); | |
676 | fcntl(s->wfd, F_SETFL, O_NONBLOCK); | |
677 | ||
678 | qemu_aio_set_fd_handler(s->rfd, posix_aio_read, NULL, posix_aio_flush, | |
679 | posix_aio_process_queue, s); | |
680 | ||
681 | ret = pthread_attr_init(&attr); | |
682 | if (ret) | |
683 | die2(ret, "pthread_attr_init"); | |
684 | ||
685 | ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); | |
686 | if (ret) | |
687 | die2(ret, "pthread_attr_setdetachstate"); | |
688 | ||
689 | QTAILQ_INIT(&request_list); | |
690 | new_thread_bh = qemu_bh_new(spawn_thread_bh_fn, NULL); | |
691 | ||
692 | posix_aio_state = s; | |
693 | return 0; | |
694 | } |