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61007b31 SH |
1 | /* |
2 | * Block layer I/O functions | |
3 | * | |
4 | * Copyright (c) 2003 Fabrice Bellard | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
24 | ||
25 | #include "trace.h" | |
7f0e9da6 | 26 | #include "sysemu/block-backend.h" |
61007b31 SH |
27 | #include "block/blockjob.h" |
28 | #include "block/block_int.h" | |
76f4afb4 | 29 | #include "block/throttle-groups.h" |
d49b6836 | 30 | #include "qemu/error-report.h" |
61007b31 SH |
31 | |
32 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
33 | ||
34 | static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, | |
35 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
36 | BlockCompletionFunc *cb, void *opaque); | |
37 | static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, | |
38 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
39 | BlockCompletionFunc *cb, void *opaque); | |
40 | static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, | |
41 | int64_t sector_num, int nb_sectors, | |
42 | QEMUIOVector *iov); | |
43 | static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, | |
44 | int64_t sector_num, int nb_sectors, | |
45 | QEMUIOVector *iov); | |
46 | static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, | |
47 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
48 | BdrvRequestFlags flags); | |
49 | static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, | |
50 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
51 | BdrvRequestFlags flags); | |
52 | static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, | |
53 | int64_t sector_num, | |
54 | QEMUIOVector *qiov, | |
55 | int nb_sectors, | |
56 | BdrvRequestFlags flags, | |
57 | BlockCompletionFunc *cb, | |
58 | void *opaque, | |
59 | bool is_write); | |
60 | static void coroutine_fn bdrv_co_do_rw(void *opaque); | |
61 | static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, | |
62 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); | |
63 | ||
64 | /* throttling disk I/O limits */ | |
65 | void bdrv_set_io_limits(BlockDriverState *bs, | |
66 | ThrottleConfig *cfg) | |
67 | { | |
68 | int i; | |
69 | ||
76f4afb4 | 70 | throttle_group_config(bs, cfg); |
61007b31 SH |
71 | |
72 | for (i = 0; i < 2; i++) { | |
73 | qemu_co_enter_next(&bs->throttled_reqs[i]); | |
74 | } | |
75 | } | |
76 | ||
77 | /* this function drain all the throttled IOs */ | |
78 | static bool bdrv_start_throttled_reqs(BlockDriverState *bs) | |
79 | { | |
80 | bool drained = false; | |
81 | bool enabled = bs->io_limits_enabled; | |
82 | int i; | |
83 | ||
84 | bs->io_limits_enabled = false; | |
85 | ||
86 | for (i = 0; i < 2; i++) { | |
87 | while (qemu_co_enter_next(&bs->throttled_reqs[i])) { | |
88 | drained = true; | |
89 | } | |
90 | } | |
91 | ||
92 | bs->io_limits_enabled = enabled; | |
93 | ||
94 | return drained; | |
95 | } | |
96 | ||
97 | void bdrv_io_limits_disable(BlockDriverState *bs) | |
98 | { | |
99 | bs->io_limits_enabled = false; | |
61007b31 | 100 | bdrv_start_throttled_reqs(bs); |
76f4afb4 | 101 | throttle_group_unregister_bs(bs); |
61007b31 SH |
102 | } |
103 | ||
104 | /* should be called before bdrv_set_io_limits if a limit is set */ | |
76f4afb4 | 105 | void bdrv_io_limits_enable(BlockDriverState *bs, const char *group) |
61007b31 | 106 | { |
61007b31 | 107 | assert(!bs->io_limits_enabled); |
76f4afb4 | 108 | throttle_group_register_bs(bs, group); |
61007b31 SH |
109 | bs->io_limits_enabled = true; |
110 | } | |
111 | ||
76f4afb4 | 112 | void bdrv_io_limits_update_group(BlockDriverState *bs, const char *group) |
61007b31 | 113 | { |
76f4afb4 AG |
114 | /* this bs is not part of any group */ |
115 | if (!bs->throttle_state) { | |
116 | return; | |
61007b31 SH |
117 | } |
118 | ||
76f4afb4 AG |
119 | /* this bs is a part of the same group than the one we want */ |
120 | if (!g_strcmp0(throttle_group_get_name(bs), group)) { | |
61007b31 SH |
121 | return; |
122 | } | |
123 | ||
76f4afb4 AG |
124 | /* need to change the group this bs belong to */ |
125 | bdrv_io_limits_disable(bs); | |
126 | bdrv_io_limits_enable(bs, group); | |
61007b31 SH |
127 | } |
128 | ||
129 | void bdrv_setup_io_funcs(BlockDriver *bdrv) | |
130 | { | |
131 | /* Block drivers without coroutine functions need emulation */ | |
132 | if (!bdrv->bdrv_co_readv) { | |
133 | bdrv->bdrv_co_readv = bdrv_co_readv_em; | |
134 | bdrv->bdrv_co_writev = bdrv_co_writev_em; | |
135 | ||
136 | /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if | |
137 | * the block driver lacks aio we need to emulate that too. | |
138 | */ | |
139 | if (!bdrv->bdrv_aio_readv) { | |
140 | /* add AIO emulation layer */ | |
141 | bdrv->bdrv_aio_readv = bdrv_aio_readv_em; | |
142 | bdrv->bdrv_aio_writev = bdrv_aio_writev_em; | |
143 | } | |
144 | } | |
145 | } | |
146 | ||
147 | void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) | |
148 | { | |
149 | BlockDriver *drv = bs->drv; | |
150 | Error *local_err = NULL; | |
151 | ||
152 | memset(&bs->bl, 0, sizeof(bs->bl)); | |
153 | ||
154 | if (!drv) { | |
155 | return; | |
156 | } | |
157 | ||
158 | /* Take some limits from the children as a default */ | |
159 | if (bs->file) { | |
9a4f4c31 | 160 | bdrv_refresh_limits(bs->file->bs, &local_err); |
61007b31 SH |
161 | if (local_err) { |
162 | error_propagate(errp, local_err); | |
163 | return; | |
164 | } | |
9a4f4c31 KW |
165 | bs->bl.opt_transfer_length = bs->file->bs->bl.opt_transfer_length; |
166 | bs->bl.max_transfer_length = bs->file->bs->bl.max_transfer_length; | |
167 | bs->bl.min_mem_alignment = bs->file->bs->bl.min_mem_alignment; | |
168 | bs->bl.opt_mem_alignment = bs->file->bs->bl.opt_mem_alignment; | |
61007b31 | 169 | } else { |
4196d2f0 | 170 | bs->bl.min_mem_alignment = 512; |
459b4e66 | 171 | bs->bl.opt_mem_alignment = getpagesize(); |
61007b31 SH |
172 | } |
173 | ||
760e0063 KW |
174 | if (bs->backing) { |
175 | bdrv_refresh_limits(bs->backing->bs, &local_err); | |
61007b31 SH |
176 | if (local_err) { |
177 | error_propagate(errp, local_err); | |
178 | return; | |
179 | } | |
180 | bs->bl.opt_transfer_length = | |
181 | MAX(bs->bl.opt_transfer_length, | |
760e0063 | 182 | bs->backing->bs->bl.opt_transfer_length); |
61007b31 SH |
183 | bs->bl.max_transfer_length = |
184 | MIN_NON_ZERO(bs->bl.max_transfer_length, | |
760e0063 | 185 | bs->backing->bs->bl.max_transfer_length); |
61007b31 SH |
186 | bs->bl.opt_mem_alignment = |
187 | MAX(bs->bl.opt_mem_alignment, | |
760e0063 | 188 | bs->backing->bs->bl.opt_mem_alignment); |
4196d2f0 DL |
189 | bs->bl.min_mem_alignment = |
190 | MAX(bs->bl.min_mem_alignment, | |
760e0063 | 191 | bs->backing->bs->bl.min_mem_alignment); |
61007b31 SH |
192 | } |
193 | ||
194 | /* Then let the driver override it */ | |
195 | if (drv->bdrv_refresh_limits) { | |
196 | drv->bdrv_refresh_limits(bs, errp); | |
197 | } | |
198 | } | |
199 | ||
200 | /** | |
201 | * The copy-on-read flag is actually a reference count so multiple users may | |
202 | * use the feature without worrying about clobbering its previous state. | |
203 | * Copy-on-read stays enabled until all users have called to disable it. | |
204 | */ | |
205 | void bdrv_enable_copy_on_read(BlockDriverState *bs) | |
206 | { | |
207 | bs->copy_on_read++; | |
208 | } | |
209 | ||
210 | void bdrv_disable_copy_on_read(BlockDriverState *bs) | |
211 | { | |
212 | assert(bs->copy_on_read > 0); | |
213 | bs->copy_on_read--; | |
214 | } | |
215 | ||
216 | /* Check if any requests are in-flight (including throttled requests) */ | |
439db28c | 217 | bool bdrv_requests_pending(BlockDriverState *bs) |
61007b31 | 218 | { |
37a639a7 KW |
219 | BdrvChild *child; |
220 | ||
61007b31 SH |
221 | if (!QLIST_EMPTY(&bs->tracked_requests)) { |
222 | return true; | |
223 | } | |
224 | if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) { | |
225 | return true; | |
226 | } | |
227 | if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) { | |
228 | return true; | |
229 | } | |
37a639a7 KW |
230 | |
231 | QLIST_FOREACH(child, &bs->children, next) { | |
232 | if (bdrv_requests_pending(child->bs)) { | |
233 | return true; | |
234 | } | |
61007b31 | 235 | } |
37a639a7 | 236 | |
61007b31 SH |
237 | return false; |
238 | } | |
239 | ||
67da1dc5 FZ |
240 | static void bdrv_drain_recurse(BlockDriverState *bs) |
241 | { | |
242 | BdrvChild *child; | |
243 | ||
244 | if (bs->drv && bs->drv->bdrv_drain) { | |
245 | bs->drv->bdrv_drain(bs); | |
246 | } | |
247 | QLIST_FOREACH(child, &bs->children, next) { | |
248 | bdrv_drain_recurse(child->bs); | |
249 | } | |
250 | } | |
251 | ||
61007b31 | 252 | /* |
67da1dc5 FZ |
253 | * Wait for pending requests to complete on a single BlockDriverState subtree, |
254 | * and suspend block driver's internal I/O until next request arrives. | |
61007b31 | 255 | * |
61007b31 SH |
256 | * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState |
257 | * AioContext. | |
7a63f3cd SH |
258 | * |
259 | * Only this BlockDriverState's AioContext is run, so in-flight requests must | |
260 | * not depend on events in other AioContexts. In that case, use | |
261 | * bdrv_drain_all() instead. | |
61007b31 SH |
262 | */ |
263 | void bdrv_drain(BlockDriverState *bs) | |
264 | { | |
f406c03c AY |
265 | bool busy = true; |
266 | ||
67da1dc5 | 267 | bdrv_drain_recurse(bs); |
f406c03c | 268 | while (busy) { |
61007b31 | 269 | /* Keep iterating */ |
f406c03c AY |
270 | bdrv_flush_io_queue(bs); |
271 | busy = bdrv_requests_pending(bs); | |
272 | busy |= aio_poll(bdrv_get_aio_context(bs), busy); | |
61007b31 SH |
273 | } |
274 | } | |
275 | ||
276 | /* | |
277 | * Wait for pending requests to complete across all BlockDriverStates | |
278 | * | |
279 | * This function does not flush data to disk, use bdrv_flush_all() for that | |
280 | * after calling this function. | |
61007b31 SH |
281 | */ |
282 | void bdrv_drain_all(void) | |
283 | { | |
284 | /* Always run first iteration so any pending completion BHs run */ | |
285 | bool busy = true; | |
286 | BlockDriverState *bs = NULL; | |
f406c03c | 287 | GSList *aio_ctxs = NULL, *ctx; |
61007b31 SH |
288 | |
289 | while ((bs = bdrv_next(bs))) { | |
290 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
291 | ||
292 | aio_context_acquire(aio_context); | |
293 | if (bs->job) { | |
294 | block_job_pause(bs->job); | |
295 | } | |
296 | aio_context_release(aio_context); | |
f406c03c | 297 | |
764ba3ae | 298 | if (!g_slist_find(aio_ctxs, aio_context)) { |
f406c03c AY |
299 | aio_ctxs = g_slist_prepend(aio_ctxs, aio_context); |
300 | } | |
61007b31 SH |
301 | } |
302 | ||
7a63f3cd SH |
303 | /* Note that completion of an asynchronous I/O operation can trigger any |
304 | * number of other I/O operations on other devices---for example a | |
305 | * coroutine can submit an I/O request to another device in response to | |
306 | * request completion. Therefore we must keep looping until there was no | |
307 | * more activity rather than simply draining each device independently. | |
308 | */ | |
61007b31 SH |
309 | while (busy) { |
310 | busy = false; | |
61007b31 | 311 | |
f406c03c AY |
312 | for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) { |
313 | AioContext *aio_context = ctx->data; | |
314 | bs = NULL; | |
61007b31 SH |
315 | |
316 | aio_context_acquire(aio_context); | |
f406c03c AY |
317 | while ((bs = bdrv_next(bs))) { |
318 | if (aio_context == bdrv_get_aio_context(bs)) { | |
319 | bdrv_flush_io_queue(bs); | |
320 | if (bdrv_requests_pending(bs)) { | |
321 | busy = true; | |
322 | aio_poll(aio_context, busy); | |
323 | } | |
324 | } | |
325 | } | |
326 | busy |= aio_poll(aio_context, false); | |
61007b31 SH |
327 | aio_context_release(aio_context); |
328 | } | |
329 | } | |
330 | ||
331 | bs = NULL; | |
332 | while ((bs = bdrv_next(bs))) { | |
333 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
334 | ||
335 | aio_context_acquire(aio_context); | |
336 | if (bs->job) { | |
337 | block_job_resume(bs->job); | |
338 | } | |
339 | aio_context_release(aio_context); | |
340 | } | |
f406c03c | 341 | g_slist_free(aio_ctxs); |
61007b31 SH |
342 | } |
343 | ||
344 | /** | |
345 | * Remove an active request from the tracked requests list | |
346 | * | |
347 | * This function should be called when a tracked request is completing. | |
348 | */ | |
349 | static void tracked_request_end(BdrvTrackedRequest *req) | |
350 | { | |
351 | if (req->serialising) { | |
352 | req->bs->serialising_in_flight--; | |
353 | } | |
354 | ||
355 | QLIST_REMOVE(req, list); | |
356 | qemu_co_queue_restart_all(&req->wait_queue); | |
357 | } | |
358 | ||
359 | /** | |
360 | * Add an active request to the tracked requests list | |
361 | */ | |
362 | static void tracked_request_begin(BdrvTrackedRequest *req, | |
363 | BlockDriverState *bs, | |
364 | int64_t offset, | |
ebde595c FZ |
365 | unsigned int bytes, |
366 | enum BdrvTrackedRequestType type) | |
61007b31 SH |
367 | { |
368 | *req = (BdrvTrackedRequest){ | |
369 | .bs = bs, | |
370 | .offset = offset, | |
371 | .bytes = bytes, | |
ebde595c | 372 | .type = type, |
61007b31 SH |
373 | .co = qemu_coroutine_self(), |
374 | .serialising = false, | |
375 | .overlap_offset = offset, | |
376 | .overlap_bytes = bytes, | |
377 | }; | |
378 | ||
379 | qemu_co_queue_init(&req->wait_queue); | |
380 | ||
381 | QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); | |
382 | } | |
383 | ||
384 | static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) | |
385 | { | |
386 | int64_t overlap_offset = req->offset & ~(align - 1); | |
387 | unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align) | |
388 | - overlap_offset; | |
389 | ||
390 | if (!req->serialising) { | |
391 | req->bs->serialising_in_flight++; | |
392 | req->serialising = true; | |
393 | } | |
394 | ||
395 | req->overlap_offset = MIN(req->overlap_offset, overlap_offset); | |
396 | req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); | |
397 | } | |
398 | ||
399 | /** | |
400 | * Round a region to cluster boundaries | |
401 | */ | |
402 | void bdrv_round_to_clusters(BlockDriverState *bs, | |
403 | int64_t sector_num, int nb_sectors, | |
404 | int64_t *cluster_sector_num, | |
405 | int *cluster_nb_sectors) | |
406 | { | |
407 | BlockDriverInfo bdi; | |
408 | ||
409 | if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { | |
410 | *cluster_sector_num = sector_num; | |
411 | *cluster_nb_sectors = nb_sectors; | |
412 | } else { | |
413 | int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; | |
414 | *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); | |
415 | *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + | |
416 | nb_sectors, c); | |
417 | } | |
418 | } | |
419 | ||
420 | static int bdrv_get_cluster_size(BlockDriverState *bs) | |
421 | { | |
422 | BlockDriverInfo bdi; | |
423 | int ret; | |
424 | ||
425 | ret = bdrv_get_info(bs, &bdi); | |
426 | if (ret < 0 || bdi.cluster_size == 0) { | |
427 | return bs->request_alignment; | |
428 | } else { | |
429 | return bdi.cluster_size; | |
430 | } | |
431 | } | |
432 | ||
433 | static bool tracked_request_overlaps(BdrvTrackedRequest *req, | |
434 | int64_t offset, unsigned int bytes) | |
435 | { | |
436 | /* aaaa bbbb */ | |
437 | if (offset >= req->overlap_offset + req->overlap_bytes) { | |
438 | return false; | |
439 | } | |
440 | /* bbbb aaaa */ | |
441 | if (req->overlap_offset >= offset + bytes) { | |
442 | return false; | |
443 | } | |
444 | return true; | |
445 | } | |
446 | ||
447 | static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) | |
448 | { | |
449 | BlockDriverState *bs = self->bs; | |
450 | BdrvTrackedRequest *req; | |
451 | bool retry; | |
452 | bool waited = false; | |
453 | ||
454 | if (!bs->serialising_in_flight) { | |
455 | return false; | |
456 | } | |
457 | ||
458 | do { | |
459 | retry = false; | |
460 | QLIST_FOREACH(req, &bs->tracked_requests, list) { | |
461 | if (req == self || (!req->serialising && !self->serialising)) { | |
462 | continue; | |
463 | } | |
464 | if (tracked_request_overlaps(req, self->overlap_offset, | |
465 | self->overlap_bytes)) | |
466 | { | |
467 | /* Hitting this means there was a reentrant request, for | |
468 | * example, a block driver issuing nested requests. This must | |
469 | * never happen since it means deadlock. | |
470 | */ | |
471 | assert(qemu_coroutine_self() != req->co); | |
472 | ||
473 | /* If the request is already (indirectly) waiting for us, or | |
474 | * will wait for us as soon as it wakes up, then just go on | |
475 | * (instead of producing a deadlock in the former case). */ | |
476 | if (!req->waiting_for) { | |
477 | self->waiting_for = req; | |
478 | qemu_co_queue_wait(&req->wait_queue); | |
479 | self->waiting_for = NULL; | |
480 | retry = true; | |
481 | waited = true; | |
482 | break; | |
483 | } | |
484 | } | |
485 | } | |
486 | } while (retry); | |
487 | ||
488 | return waited; | |
489 | } | |
490 | ||
491 | static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, | |
492 | size_t size) | |
493 | { | |
494 | if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) { | |
495 | return -EIO; | |
496 | } | |
497 | ||
498 | if (!bdrv_is_inserted(bs)) { | |
499 | return -ENOMEDIUM; | |
500 | } | |
501 | ||
502 | if (offset < 0) { | |
503 | return -EIO; | |
504 | } | |
505 | ||
506 | return 0; | |
507 | } | |
508 | ||
509 | static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, | |
510 | int nb_sectors) | |
511 | { | |
512 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
513 | return -EIO; | |
514 | } | |
515 | ||
516 | return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE, | |
517 | nb_sectors * BDRV_SECTOR_SIZE); | |
518 | } | |
519 | ||
520 | typedef struct RwCo { | |
521 | BlockDriverState *bs; | |
522 | int64_t offset; | |
523 | QEMUIOVector *qiov; | |
524 | bool is_write; | |
525 | int ret; | |
526 | BdrvRequestFlags flags; | |
527 | } RwCo; | |
528 | ||
529 | static void coroutine_fn bdrv_rw_co_entry(void *opaque) | |
530 | { | |
531 | RwCo *rwco = opaque; | |
532 | ||
533 | if (!rwco->is_write) { | |
534 | rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset, | |
535 | rwco->qiov->size, rwco->qiov, | |
536 | rwco->flags); | |
537 | } else { | |
538 | rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset, | |
539 | rwco->qiov->size, rwco->qiov, | |
540 | rwco->flags); | |
541 | } | |
542 | } | |
543 | ||
544 | /* | |
545 | * Process a vectored synchronous request using coroutines | |
546 | */ | |
547 | static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset, | |
548 | QEMUIOVector *qiov, bool is_write, | |
549 | BdrvRequestFlags flags) | |
550 | { | |
551 | Coroutine *co; | |
552 | RwCo rwco = { | |
553 | .bs = bs, | |
554 | .offset = offset, | |
555 | .qiov = qiov, | |
556 | .is_write = is_write, | |
557 | .ret = NOT_DONE, | |
558 | .flags = flags, | |
559 | }; | |
560 | ||
561 | /** | |
562 | * In sync call context, when the vcpu is blocked, this throttling timer | |
563 | * will not fire; so the I/O throttling function has to be disabled here | |
564 | * if it has been enabled. | |
565 | */ | |
566 | if (bs->io_limits_enabled) { | |
567 | fprintf(stderr, "Disabling I/O throttling on '%s' due " | |
568 | "to synchronous I/O.\n", bdrv_get_device_name(bs)); | |
569 | bdrv_io_limits_disable(bs); | |
570 | } | |
571 | ||
572 | if (qemu_in_coroutine()) { | |
573 | /* Fast-path if already in coroutine context */ | |
574 | bdrv_rw_co_entry(&rwco); | |
575 | } else { | |
576 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
577 | ||
578 | co = qemu_coroutine_create(bdrv_rw_co_entry); | |
579 | qemu_coroutine_enter(co, &rwco); | |
580 | while (rwco.ret == NOT_DONE) { | |
581 | aio_poll(aio_context, true); | |
582 | } | |
583 | } | |
584 | return rwco.ret; | |
585 | } | |
586 | ||
587 | /* | |
588 | * Process a synchronous request using coroutines | |
589 | */ | |
590 | static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, | |
591 | int nb_sectors, bool is_write, BdrvRequestFlags flags) | |
592 | { | |
593 | QEMUIOVector qiov; | |
594 | struct iovec iov = { | |
595 | .iov_base = (void *)buf, | |
596 | .iov_len = nb_sectors * BDRV_SECTOR_SIZE, | |
597 | }; | |
598 | ||
599 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
600 | return -EINVAL; | |
601 | } | |
602 | ||
603 | qemu_iovec_init_external(&qiov, &iov, 1); | |
604 | return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS, | |
605 | &qiov, is_write, flags); | |
606 | } | |
607 | ||
608 | /* return < 0 if error. See bdrv_write() for the return codes */ | |
609 | int bdrv_read(BlockDriverState *bs, int64_t sector_num, | |
610 | uint8_t *buf, int nb_sectors) | |
611 | { | |
612 | return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0); | |
613 | } | |
614 | ||
615 | /* Just like bdrv_read(), but with I/O throttling temporarily disabled */ | |
616 | int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num, | |
617 | uint8_t *buf, int nb_sectors) | |
618 | { | |
619 | bool enabled; | |
620 | int ret; | |
621 | ||
622 | enabled = bs->io_limits_enabled; | |
623 | bs->io_limits_enabled = false; | |
624 | ret = bdrv_read(bs, sector_num, buf, nb_sectors); | |
625 | bs->io_limits_enabled = enabled; | |
626 | return ret; | |
627 | } | |
628 | ||
629 | /* Return < 0 if error. Important errors are: | |
630 | -EIO generic I/O error (may happen for all errors) | |
631 | -ENOMEDIUM No media inserted. | |
632 | -EINVAL Invalid sector number or nb_sectors | |
633 | -EACCES Trying to write a read-only device | |
634 | */ | |
635 | int bdrv_write(BlockDriverState *bs, int64_t sector_num, | |
636 | const uint8_t *buf, int nb_sectors) | |
637 | { | |
638 | return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0); | |
639 | } | |
640 | ||
641 | int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, | |
642 | int nb_sectors, BdrvRequestFlags flags) | |
643 | { | |
644 | return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true, | |
645 | BDRV_REQ_ZERO_WRITE | flags); | |
646 | } | |
647 | ||
648 | /* | |
649 | * Completely zero out a block device with the help of bdrv_write_zeroes. | |
650 | * The operation is sped up by checking the block status and only writing | |
651 | * zeroes to the device if they currently do not return zeroes. Optional | |
652 | * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP). | |
653 | * | |
654 | * Returns < 0 on error, 0 on success. For error codes see bdrv_write(). | |
655 | */ | |
656 | int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags) | |
657 | { | |
658 | int64_t target_sectors, ret, nb_sectors, sector_num = 0; | |
659 | int n; | |
660 | ||
661 | target_sectors = bdrv_nb_sectors(bs); | |
662 | if (target_sectors < 0) { | |
663 | return target_sectors; | |
664 | } | |
665 | ||
666 | for (;;) { | |
667 | nb_sectors = MIN(target_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS); | |
668 | if (nb_sectors <= 0) { | |
669 | return 0; | |
670 | } | |
671 | ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n); | |
672 | if (ret < 0) { | |
673 | error_report("error getting block status at sector %" PRId64 ": %s", | |
674 | sector_num, strerror(-ret)); | |
675 | return ret; | |
676 | } | |
677 | if (ret & BDRV_BLOCK_ZERO) { | |
678 | sector_num += n; | |
679 | continue; | |
680 | } | |
681 | ret = bdrv_write_zeroes(bs, sector_num, n, flags); | |
682 | if (ret < 0) { | |
683 | error_report("error writing zeroes at sector %" PRId64 ": %s", | |
684 | sector_num, strerror(-ret)); | |
685 | return ret; | |
686 | } | |
687 | sector_num += n; | |
688 | } | |
689 | } | |
690 | ||
691 | int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes) | |
692 | { | |
693 | QEMUIOVector qiov; | |
694 | struct iovec iov = { | |
695 | .iov_base = (void *)buf, | |
696 | .iov_len = bytes, | |
697 | }; | |
698 | int ret; | |
699 | ||
700 | if (bytes < 0) { | |
701 | return -EINVAL; | |
702 | } | |
703 | ||
704 | qemu_iovec_init_external(&qiov, &iov, 1); | |
705 | ret = bdrv_prwv_co(bs, offset, &qiov, false, 0); | |
706 | if (ret < 0) { | |
707 | return ret; | |
708 | } | |
709 | ||
710 | return bytes; | |
711 | } | |
712 | ||
713 | int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) | |
714 | { | |
715 | int ret; | |
716 | ||
717 | ret = bdrv_prwv_co(bs, offset, qiov, true, 0); | |
718 | if (ret < 0) { | |
719 | return ret; | |
720 | } | |
721 | ||
722 | return qiov->size; | |
723 | } | |
724 | ||
725 | int bdrv_pwrite(BlockDriverState *bs, int64_t offset, | |
726 | const void *buf, int bytes) | |
727 | { | |
728 | QEMUIOVector qiov; | |
729 | struct iovec iov = { | |
730 | .iov_base = (void *) buf, | |
731 | .iov_len = bytes, | |
732 | }; | |
733 | ||
734 | if (bytes < 0) { | |
735 | return -EINVAL; | |
736 | } | |
737 | ||
738 | qemu_iovec_init_external(&qiov, &iov, 1); | |
739 | return bdrv_pwritev(bs, offset, &qiov); | |
740 | } | |
741 | ||
742 | /* | |
743 | * Writes to the file and ensures that no writes are reordered across this | |
744 | * request (acts as a barrier) | |
745 | * | |
746 | * Returns 0 on success, -errno in error cases. | |
747 | */ | |
748 | int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, | |
749 | const void *buf, int count) | |
750 | { | |
751 | int ret; | |
752 | ||
753 | ret = bdrv_pwrite(bs, offset, buf, count); | |
754 | if (ret < 0) { | |
755 | return ret; | |
756 | } | |
757 | ||
758 | /* No flush needed for cache modes that already do it */ | |
759 | if (bs->enable_write_cache) { | |
760 | bdrv_flush(bs); | |
761 | } | |
762 | ||
763 | return 0; | |
764 | } | |
765 | ||
766 | static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, | |
767 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) | |
768 | { | |
769 | /* Perform I/O through a temporary buffer so that users who scribble over | |
770 | * their read buffer while the operation is in progress do not end up | |
771 | * modifying the image file. This is critical for zero-copy guest I/O | |
772 | * where anything might happen inside guest memory. | |
773 | */ | |
774 | void *bounce_buffer; | |
775 | ||
776 | BlockDriver *drv = bs->drv; | |
777 | struct iovec iov; | |
778 | QEMUIOVector bounce_qiov; | |
779 | int64_t cluster_sector_num; | |
780 | int cluster_nb_sectors; | |
781 | size_t skip_bytes; | |
782 | int ret; | |
783 | ||
784 | /* Cover entire cluster so no additional backing file I/O is required when | |
785 | * allocating cluster in the image file. | |
786 | */ | |
787 | bdrv_round_to_clusters(bs, sector_num, nb_sectors, | |
788 | &cluster_sector_num, &cluster_nb_sectors); | |
789 | ||
790 | trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, | |
791 | cluster_sector_num, cluster_nb_sectors); | |
792 | ||
793 | iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; | |
794 | iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len); | |
795 | if (bounce_buffer == NULL) { | |
796 | ret = -ENOMEM; | |
797 | goto err; | |
798 | } | |
799 | ||
800 | qemu_iovec_init_external(&bounce_qiov, &iov, 1); | |
801 | ||
802 | ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, | |
803 | &bounce_qiov); | |
804 | if (ret < 0) { | |
805 | goto err; | |
806 | } | |
807 | ||
808 | if (drv->bdrv_co_write_zeroes && | |
809 | buffer_is_zero(bounce_buffer, iov.iov_len)) { | |
810 | ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, | |
811 | cluster_nb_sectors, 0); | |
812 | } else { | |
813 | /* This does not change the data on the disk, it is not necessary | |
814 | * to flush even in cache=writethrough mode. | |
815 | */ | |
816 | ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, | |
817 | &bounce_qiov); | |
818 | } | |
819 | ||
820 | if (ret < 0) { | |
821 | /* It might be okay to ignore write errors for guest requests. If this | |
822 | * is a deliberate copy-on-read then we don't want to ignore the error. | |
823 | * Simply report it in all cases. | |
824 | */ | |
825 | goto err; | |
826 | } | |
827 | ||
828 | skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; | |
829 | qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, | |
830 | nb_sectors * BDRV_SECTOR_SIZE); | |
831 | ||
832 | err: | |
833 | qemu_vfree(bounce_buffer); | |
834 | return ret; | |
835 | } | |
836 | ||
837 | /* | |
838 | * Forwards an already correctly aligned request to the BlockDriver. This | |
839 | * handles copy on read and zeroing after EOF; any other features must be | |
840 | * implemented by the caller. | |
841 | */ | |
842 | static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, | |
843 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, | |
844 | int64_t align, QEMUIOVector *qiov, int flags) | |
845 | { | |
846 | BlockDriver *drv = bs->drv; | |
847 | int ret; | |
848 | ||
849 | int64_t sector_num = offset >> BDRV_SECTOR_BITS; | |
850 | unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
851 | ||
852 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
853 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
854 | assert(!qiov || bytes == qiov->size); | |
855 | ||
856 | /* Handle Copy on Read and associated serialisation */ | |
857 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
858 | /* If we touch the same cluster it counts as an overlap. This | |
859 | * guarantees that allocating writes will be serialized and not race | |
860 | * with each other for the same cluster. For example, in copy-on-read | |
861 | * it ensures that the CoR read and write operations are atomic and | |
862 | * guest writes cannot interleave between them. */ | |
863 | mark_request_serialising(req, bdrv_get_cluster_size(bs)); | |
864 | } | |
865 | ||
866 | wait_serialising_requests(req); | |
867 | ||
868 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
869 | int pnum; | |
870 | ||
871 | ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum); | |
872 | if (ret < 0) { | |
873 | goto out; | |
874 | } | |
875 | ||
876 | if (!ret || pnum != nb_sectors) { | |
877 | ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); | |
878 | goto out; | |
879 | } | |
880 | } | |
881 | ||
882 | /* Forward the request to the BlockDriver */ | |
883 | if (!bs->zero_beyond_eof) { | |
884 | ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); | |
885 | } else { | |
886 | /* Read zeros after EOF */ | |
887 | int64_t total_sectors, max_nb_sectors; | |
888 | ||
889 | total_sectors = bdrv_nb_sectors(bs); | |
890 | if (total_sectors < 0) { | |
891 | ret = total_sectors; | |
892 | goto out; | |
893 | } | |
894 | ||
895 | max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num), | |
896 | align >> BDRV_SECTOR_BITS); | |
897 | if (nb_sectors < max_nb_sectors) { | |
898 | ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); | |
899 | } else if (max_nb_sectors > 0) { | |
900 | QEMUIOVector local_qiov; | |
901 | ||
902 | qemu_iovec_init(&local_qiov, qiov->niov); | |
903 | qemu_iovec_concat(&local_qiov, qiov, 0, | |
904 | max_nb_sectors * BDRV_SECTOR_SIZE); | |
905 | ||
906 | ret = drv->bdrv_co_readv(bs, sector_num, max_nb_sectors, | |
907 | &local_qiov); | |
908 | ||
909 | qemu_iovec_destroy(&local_qiov); | |
910 | } else { | |
911 | ret = 0; | |
912 | } | |
913 | ||
914 | /* Reading beyond end of file is supposed to produce zeroes */ | |
915 | if (ret == 0 && total_sectors < sector_num + nb_sectors) { | |
916 | uint64_t offset = MAX(0, total_sectors - sector_num); | |
917 | uint64_t bytes = (sector_num + nb_sectors - offset) * | |
918 | BDRV_SECTOR_SIZE; | |
919 | qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes); | |
920 | } | |
921 | } | |
922 | ||
923 | out: | |
924 | return ret; | |
925 | } | |
926 | ||
61007b31 SH |
927 | /* |
928 | * Handle a read request in coroutine context | |
929 | */ | |
930 | static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, | |
931 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
932 | BdrvRequestFlags flags) | |
933 | { | |
934 | BlockDriver *drv = bs->drv; | |
935 | BdrvTrackedRequest req; | |
936 | ||
d01c07f2 FZ |
937 | /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ |
938 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
61007b31 SH |
939 | uint8_t *head_buf = NULL; |
940 | uint8_t *tail_buf = NULL; | |
941 | QEMUIOVector local_qiov; | |
942 | bool use_local_qiov = false; | |
943 | int ret; | |
944 | ||
945 | if (!drv) { | |
946 | return -ENOMEDIUM; | |
947 | } | |
948 | ||
949 | ret = bdrv_check_byte_request(bs, offset, bytes); | |
950 | if (ret < 0) { | |
951 | return ret; | |
952 | } | |
953 | ||
9568b511 WC |
954 | /* Don't do copy-on-read if we read data before write operation */ |
955 | if (bs->copy_on_read && !(flags & BDRV_REQ_NO_COPY_ON_READ)) { | |
61007b31 SH |
956 | flags |= BDRV_REQ_COPY_ON_READ; |
957 | } | |
958 | ||
959 | /* throttling disk I/O */ | |
960 | if (bs->io_limits_enabled) { | |
76f4afb4 | 961 | throttle_group_co_io_limits_intercept(bs, bytes, false); |
61007b31 SH |
962 | } |
963 | ||
964 | /* Align read if necessary by padding qiov */ | |
965 | if (offset & (align - 1)) { | |
966 | head_buf = qemu_blockalign(bs, align); | |
967 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
968 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
969 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
970 | use_local_qiov = true; | |
971 | ||
972 | bytes += offset & (align - 1); | |
973 | offset = offset & ~(align - 1); | |
974 | } | |
975 | ||
976 | if ((offset + bytes) & (align - 1)) { | |
977 | if (!use_local_qiov) { | |
978 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
979 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
980 | use_local_qiov = true; | |
981 | } | |
982 | tail_buf = qemu_blockalign(bs, align); | |
983 | qemu_iovec_add(&local_qiov, tail_buf, | |
984 | align - ((offset + bytes) & (align - 1))); | |
985 | ||
986 | bytes = ROUND_UP(bytes, align); | |
987 | } | |
988 | ||
ebde595c | 989 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ); |
61007b31 SH |
990 | ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align, |
991 | use_local_qiov ? &local_qiov : qiov, | |
992 | flags); | |
993 | tracked_request_end(&req); | |
994 | ||
995 | if (use_local_qiov) { | |
996 | qemu_iovec_destroy(&local_qiov); | |
997 | qemu_vfree(head_buf); | |
998 | qemu_vfree(tail_buf); | |
999 | } | |
1000 | ||
1001 | return ret; | |
1002 | } | |
1003 | ||
1004 | static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, | |
1005 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, | |
1006 | BdrvRequestFlags flags) | |
1007 | { | |
1008 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
1009 | return -EINVAL; | |
1010 | } | |
1011 | ||
1012 | return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS, | |
1013 | nb_sectors << BDRV_SECTOR_BITS, qiov, flags); | |
1014 | } | |
1015 | ||
1016 | int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, | |
1017 | int nb_sectors, QEMUIOVector *qiov) | |
1018 | { | |
1019 | trace_bdrv_co_readv(bs, sector_num, nb_sectors); | |
1020 | ||
1021 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); | |
1022 | } | |
1023 | ||
9568b511 WC |
1024 | int coroutine_fn bdrv_co_no_copy_on_readv(BlockDriverState *bs, |
1025 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) | |
1026 | { | |
1027 | trace_bdrv_co_no_copy_on_readv(bs, sector_num, nb_sectors); | |
1028 | ||
1029 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, | |
1030 | BDRV_REQ_NO_COPY_ON_READ); | |
1031 | } | |
1032 | ||
61007b31 SH |
1033 | int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, |
1034 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) | |
1035 | { | |
1036 | trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); | |
1037 | ||
1038 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, | |
1039 | BDRV_REQ_COPY_ON_READ); | |
1040 | } | |
1041 | ||
1042 | #define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768 | |
1043 | ||
1044 | static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, | |
1045 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) | |
1046 | { | |
1047 | BlockDriver *drv = bs->drv; | |
1048 | QEMUIOVector qiov; | |
1049 | struct iovec iov = {0}; | |
1050 | int ret = 0; | |
1051 | ||
1052 | int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes, | |
1053 | BDRV_REQUEST_MAX_SECTORS); | |
1054 | ||
1055 | while (nb_sectors > 0 && !ret) { | |
1056 | int num = nb_sectors; | |
1057 | ||
1058 | /* Align request. Block drivers can expect the "bulk" of the request | |
1059 | * to be aligned. | |
1060 | */ | |
1061 | if (bs->bl.write_zeroes_alignment | |
1062 | && num > bs->bl.write_zeroes_alignment) { | |
1063 | if (sector_num % bs->bl.write_zeroes_alignment != 0) { | |
1064 | /* Make a small request up to the first aligned sector. */ | |
1065 | num = bs->bl.write_zeroes_alignment; | |
1066 | num -= sector_num % bs->bl.write_zeroes_alignment; | |
1067 | } else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) { | |
1068 | /* Shorten the request to the last aligned sector. num cannot | |
1069 | * underflow because num > bs->bl.write_zeroes_alignment. | |
1070 | */ | |
1071 | num -= (sector_num + num) % bs->bl.write_zeroes_alignment; | |
1072 | } | |
1073 | } | |
1074 | ||
1075 | /* limit request size */ | |
1076 | if (num > max_write_zeroes) { | |
1077 | num = max_write_zeroes; | |
1078 | } | |
1079 | ||
1080 | ret = -ENOTSUP; | |
1081 | /* First try the efficient write zeroes operation */ | |
1082 | if (drv->bdrv_co_write_zeroes) { | |
1083 | ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags); | |
1084 | } | |
1085 | ||
1086 | if (ret == -ENOTSUP) { | |
1087 | /* Fall back to bounce buffer if write zeroes is unsupported */ | |
1088 | int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length, | |
1089 | MAX_WRITE_ZEROES_BOUNCE_BUFFER); | |
1090 | num = MIN(num, max_xfer_len); | |
1091 | iov.iov_len = num * BDRV_SECTOR_SIZE; | |
1092 | if (iov.iov_base == NULL) { | |
1093 | iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE); | |
1094 | if (iov.iov_base == NULL) { | |
1095 | ret = -ENOMEM; | |
1096 | goto fail; | |
1097 | } | |
1098 | memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE); | |
1099 | } | |
1100 | qemu_iovec_init_external(&qiov, &iov, 1); | |
1101 | ||
1102 | ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov); | |
1103 | ||
1104 | /* Keep bounce buffer around if it is big enough for all | |
1105 | * all future requests. | |
1106 | */ | |
1107 | if (num < max_xfer_len) { | |
1108 | qemu_vfree(iov.iov_base); | |
1109 | iov.iov_base = NULL; | |
1110 | } | |
1111 | } | |
1112 | ||
1113 | sector_num += num; | |
1114 | nb_sectors -= num; | |
1115 | } | |
1116 | ||
1117 | fail: | |
1118 | qemu_vfree(iov.iov_base); | |
1119 | return ret; | |
1120 | } | |
1121 | ||
1122 | /* | |
1123 | * Forwards an already correctly aligned write request to the BlockDriver. | |
1124 | */ | |
1125 | static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, | |
1126 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, | |
1127 | QEMUIOVector *qiov, int flags) | |
1128 | { | |
1129 | BlockDriver *drv = bs->drv; | |
1130 | bool waited; | |
1131 | int ret; | |
1132 | ||
1133 | int64_t sector_num = offset >> BDRV_SECTOR_BITS; | |
1134 | unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
1135 | ||
1136 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1137 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1138 | assert(!qiov || bytes == qiov->size); | |
1139 | ||
1140 | waited = wait_serialising_requests(req); | |
1141 | assert(!waited || !req->serialising); | |
1142 | assert(req->overlap_offset <= offset); | |
1143 | assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); | |
1144 | ||
1145 | ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); | |
1146 | ||
1147 | if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF && | |
1148 | !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes && | |
1149 | qemu_iovec_is_zero(qiov)) { | |
1150 | flags |= BDRV_REQ_ZERO_WRITE; | |
1151 | if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) { | |
1152 | flags |= BDRV_REQ_MAY_UNMAP; | |
1153 | } | |
1154 | } | |
1155 | ||
1156 | if (ret < 0) { | |
1157 | /* Do nothing, write notifier decided to fail this request */ | |
1158 | } else if (flags & BDRV_REQ_ZERO_WRITE) { | |
9a4f4c31 | 1159 | bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO); |
61007b31 SH |
1160 | ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags); |
1161 | } else { | |
9a4f4c31 | 1162 | bdrv_debug_event(bs, BLKDBG_PWRITEV); |
61007b31 SH |
1163 | ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); |
1164 | } | |
9a4f4c31 | 1165 | bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE); |
61007b31 SH |
1166 | |
1167 | if (ret == 0 && !bs->enable_write_cache) { | |
1168 | ret = bdrv_co_flush(bs); | |
1169 | } | |
1170 | ||
1171 | bdrv_set_dirty(bs, sector_num, nb_sectors); | |
1172 | ||
53d8f9d8 HR |
1173 | if (bs->wr_highest_offset < offset + bytes) { |
1174 | bs->wr_highest_offset = offset + bytes; | |
1175 | } | |
61007b31 SH |
1176 | |
1177 | if (ret >= 0) { | |
1178 | bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); | |
1179 | } | |
1180 | ||
1181 | return ret; | |
1182 | } | |
1183 | ||
9eeb6dd1 FZ |
1184 | static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, |
1185 | int64_t offset, | |
1186 | unsigned int bytes, | |
1187 | BdrvRequestFlags flags, | |
1188 | BdrvTrackedRequest *req) | |
1189 | { | |
1190 | uint8_t *buf = NULL; | |
1191 | QEMUIOVector local_qiov; | |
1192 | struct iovec iov; | |
1193 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
1194 | unsigned int head_padding_bytes, tail_padding_bytes; | |
1195 | int ret = 0; | |
1196 | ||
1197 | head_padding_bytes = offset & (align - 1); | |
1198 | tail_padding_bytes = align - ((offset + bytes) & (align - 1)); | |
1199 | ||
1200 | ||
1201 | assert(flags & BDRV_REQ_ZERO_WRITE); | |
1202 | if (head_padding_bytes || tail_padding_bytes) { | |
1203 | buf = qemu_blockalign(bs, align); | |
1204 | iov = (struct iovec) { | |
1205 | .iov_base = buf, | |
1206 | .iov_len = align, | |
1207 | }; | |
1208 | qemu_iovec_init_external(&local_qiov, &iov, 1); | |
1209 | } | |
1210 | if (head_padding_bytes) { | |
1211 | uint64_t zero_bytes = MIN(bytes, align - head_padding_bytes); | |
1212 | ||
1213 | /* RMW the unaligned part before head. */ | |
1214 | mark_request_serialising(req, align); | |
1215 | wait_serialising_requests(req); | |
9a4f4c31 | 1216 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); |
9eeb6dd1 FZ |
1217 | ret = bdrv_aligned_preadv(bs, req, offset & ~(align - 1), align, |
1218 | align, &local_qiov, 0); | |
1219 | if (ret < 0) { | |
1220 | goto fail; | |
1221 | } | |
9a4f4c31 | 1222 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); |
9eeb6dd1 FZ |
1223 | |
1224 | memset(buf + head_padding_bytes, 0, zero_bytes); | |
1225 | ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align, | |
1226 | &local_qiov, | |
1227 | flags & ~BDRV_REQ_ZERO_WRITE); | |
1228 | if (ret < 0) { | |
1229 | goto fail; | |
1230 | } | |
1231 | offset += zero_bytes; | |
1232 | bytes -= zero_bytes; | |
1233 | } | |
1234 | ||
1235 | assert(!bytes || (offset & (align - 1)) == 0); | |
1236 | if (bytes >= align) { | |
1237 | /* Write the aligned part in the middle. */ | |
1238 | uint64_t aligned_bytes = bytes & ~(align - 1); | |
1239 | ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes, | |
1240 | NULL, flags); | |
1241 | if (ret < 0) { | |
1242 | goto fail; | |
1243 | } | |
1244 | bytes -= aligned_bytes; | |
1245 | offset += aligned_bytes; | |
1246 | } | |
1247 | ||
1248 | assert(!bytes || (offset & (align - 1)) == 0); | |
1249 | if (bytes) { | |
1250 | assert(align == tail_padding_bytes + bytes); | |
1251 | /* RMW the unaligned part after tail. */ | |
1252 | mark_request_serialising(req, align); | |
1253 | wait_serialising_requests(req); | |
9a4f4c31 | 1254 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); |
9eeb6dd1 FZ |
1255 | ret = bdrv_aligned_preadv(bs, req, offset, align, |
1256 | align, &local_qiov, 0); | |
1257 | if (ret < 0) { | |
1258 | goto fail; | |
1259 | } | |
9a4f4c31 | 1260 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); |
9eeb6dd1 FZ |
1261 | |
1262 | memset(buf, 0, bytes); | |
1263 | ret = bdrv_aligned_pwritev(bs, req, offset, align, | |
1264 | &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE); | |
1265 | } | |
1266 | fail: | |
1267 | qemu_vfree(buf); | |
1268 | return ret; | |
1269 | ||
1270 | } | |
1271 | ||
61007b31 SH |
1272 | /* |
1273 | * Handle a write request in coroutine context | |
1274 | */ | |
1275 | static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, | |
1276 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
1277 | BdrvRequestFlags flags) | |
1278 | { | |
1279 | BdrvTrackedRequest req; | |
d01c07f2 FZ |
1280 | /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ |
1281 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
61007b31 SH |
1282 | uint8_t *head_buf = NULL; |
1283 | uint8_t *tail_buf = NULL; | |
1284 | QEMUIOVector local_qiov; | |
1285 | bool use_local_qiov = false; | |
1286 | int ret; | |
1287 | ||
1288 | if (!bs->drv) { | |
1289 | return -ENOMEDIUM; | |
1290 | } | |
1291 | if (bs->read_only) { | |
eaf5fe2d | 1292 | return -EPERM; |
61007b31 SH |
1293 | } |
1294 | ||
1295 | ret = bdrv_check_byte_request(bs, offset, bytes); | |
1296 | if (ret < 0) { | |
1297 | return ret; | |
1298 | } | |
1299 | ||
1300 | /* throttling disk I/O */ | |
1301 | if (bs->io_limits_enabled) { | |
76f4afb4 | 1302 | throttle_group_co_io_limits_intercept(bs, bytes, true); |
61007b31 SH |
1303 | } |
1304 | ||
1305 | /* | |
1306 | * Align write if necessary by performing a read-modify-write cycle. | |
1307 | * Pad qiov with the read parts and be sure to have a tracked request not | |
1308 | * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle. | |
1309 | */ | |
ebde595c | 1310 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE); |
61007b31 | 1311 | |
9eeb6dd1 FZ |
1312 | if (!qiov) { |
1313 | ret = bdrv_co_do_zero_pwritev(bs, offset, bytes, flags, &req); | |
1314 | goto out; | |
1315 | } | |
1316 | ||
61007b31 SH |
1317 | if (offset & (align - 1)) { |
1318 | QEMUIOVector head_qiov; | |
1319 | struct iovec head_iov; | |
1320 | ||
1321 | mark_request_serialising(&req, align); | |
1322 | wait_serialising_requests(&req); | |
1323 | ||
1324 | head_buf = qemu_blockalign(bs, align); | |
1325 | head_iov = (struct iovec) { | |
1326 | .iov_base = head_buf, | |
1327 | .iov_len = align, | |
1328 | }; | |
1329 | qemu_iovec_init_external(&head_qiov, &head_iov, 1); | |
1330 | ||
9a4f4c31 | 1331 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); |
61007b31 SH |
1332 | ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align, |
1333 | align, &head_qiov, 0); | |
1334 | if (ret < 0) { | |
1335 | goto fail; | |
1336 | } | |
9a4f4c31 | 1337 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); |
61007b31 SH |
1338 | |
1339 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
1340 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
1341 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1342 | use_local_qiov = true; | |
1343 | ||
1344 | bytes += offset & (align - 1); | |
1345 | offset = offset & ~(align - 1); | |
1346 | } | |
1347 | ||
1348 | if ((offset + bytes) & (align - 1)) { | |
1349 | QEMUIOVector tail_qiov; | |
1350 | struct iovec tail_iov; | |
1351 | size_t tail_bytes; | |
1352 | bool waited; | |
1353 | ||
1354 | mark_request_serialising(&req, align); | |
1355 | waited = wait_serialising_requests(&req); | |
1356 | assert(!waited || !use_local_qiov); | |
1357 | ||
1358 | tail_buf = qemu_blockalign(bs, align); | |
1359 | tail_iov = (struct iovec) { | |
1360 | .iov_base = tail_buf, | |
1361 | .iov_len = align, | |
1362 | }; | |
1363 | qemu_iovec_init_external(&tail_qiov, &tail_iov, 1); | |
1364 | ||
9a4f4c31 | 1365 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); |
61007b31 SH |
1366 | ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align, |
1367 | align, &tail_qiov, 0); | |
1368 | if (ret < 0) { | |
1369 | goto fail; | |
1370 | } | |
9a4f4c31 | 1371 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); |
61007b31 SH |
1372 | |
1373 | if (!use_local_qiov) { | |
1374 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
1375 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1376 | use_local_qiov = true; | |
1377 | } | |
1378 | ||
1379 | tail_bytes = (offset + bytes) & (align - 1); | |
1380 | qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes); | |
1381 | ||
1382 | bytes = ROUND_UP(bytes, align); | |
1383 | } | |
1384 | ||
61007b31 SH |
1385 | ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, |
1386 | use_local_qiov ? &local_qiov : qiov, | |
1387 | flags); | |
1388 | ||
1389 | fail: | |
61007b31 SH |
1390 | |
1391 | if (use_local_qiov) { | |
1392 | qemu_iovec_destroy(&local_qiov); | |
1393 | } | |
1394 | qemu_vfree(head_buf); | |
1395 | qemu_vfree(tail_buf); | |
9eeb6dd1 FZ |
1396 | out: |
1397 | tracked_request_end(&req); | |
61007b31 SH |
1398 | return ret; |
1399 | } | |
1400 | ||
1401 | static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, | |
1402 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, | |
1403 | BdrvRequestFlags flags) | |
1404 | { | |
1405 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
1406 | return -EINVAL; | |
1407 | } | |
1408 | ||
1409 | return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS, | |
1410 | nb_sectors << BDRV_SECTOR_BITS, qiov, flags); | |
1411 | } | |
1412 | ||
1413 | int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, | |
1414 | int nb_sectors, QEMUIOVector *qiov) | |
1415 | { | |
1416 | trace_bdrv_co_writev(bs, sector_num, nb_sectors); | |
1417 | ||
1418 | return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); | |
1419 | } | |
1420 | ||
1421 | int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, | |
1422 | int64_t sector_num, int nb_sectors, | |
1423 | BdrvRequestFlags flags) | |
1424 | { | |
61007b31 SH |
1425 | trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags); |
1426 | ||
1427 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
1428 | flags &= ~BDRV_REQ_MAY_UNMAP; | |
1429 | } | |
61007b31 | 1430 | |
d01c07f2 FZ |
1431 | return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, |
1432 | BDRV_REQ_ZERO_WRITE | flags); | |
61007b31 SH |
1433 | } |
1434 | ||
1435 | int bdrv_flush_all(void) | |
1436 | { | |
1437 | BlockDriverState *bs = NULL; | |
1438 | int result = 0; | |
1439 | ||
1440 | while ((bs = bdrv_next(bs))) { | |
1441 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1442 | int ret; | |
1443 | ||
1444 | aio_context_acquire(aio_context); | |
1445 | ret = bdrv_flush(bs); | |
1446 | if (ret < 0 && !result) { | |
1447 | result = ret; | |
1448 | } | |
1449 | aio_context_release(aio_context); | |
1450 | } | |
1451 | ||
1452 | return result; | |
1453 | } | |
1454 | ||
1455 | typedef struct BdrvCoGetBlockStatusData { | |
1456 | BlockDriverState *bs; | |
1457 | BlockDriverState *base; | |
1458 | int64_t sector_num; | |
1459 | int nb_sectors; | |
1460 | int *pnum; | |
1461 | int64_t ret; | |
1462 | bool done; | |
1463 | } BdrvCoGetBlockStatusData; | |
1464 | ||
1465 | /* | |
1466 | * Returns the allocation status of the specified sectors. | |
1467 | * Drivers not implementing the functionality are assumed to not support | |
1468 | * backing files, hence all their sectors are reported as allocated. | |
1469 | * | |
1470 | * If 'sector_num' is beyond the end of the disk image the return value is 0 | |
1471 | * and 'pnum' is set to 0. | |
1472 | * | |
1473 | * 'pnum' is set to the number of sectors (including and immediately following | |
1474 | * the specified sector) that are known to be in the same | |
1475 | * allocated/unallocated state. | |
1476 | * | |
1477 | * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes | |
1478 | * beyond the end of the disk image it will be clamped. | |
1479 | */ | |
1480 | static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, | |
1481 | int64_t sector_num, | |
1482 | int nb_sectors, int *pnum) | |
1483 | { | |
1484 | int64_t total_sectors; | |
1485 | int64_t n; | |
1486 | int64_t ret, ret2; | |
1487 | ||
1488 | total_sectors = bdrv_nb_sectors(bs); | |
1489 | if (total_sectors < 0) { | |
1490 | return total_sectors; | |
1491 | } | |
1492 | ||
1493 | if (sector_num >= total_sectors) { | |
1494 | *pnum = 0; | |
1495 | return 0; | |
1496 | } | |
1497 | ||
1498 | n = total_sectors - sector_num; | |
1499 | if (n < nb_sectors) { | |
1500 | nb_sectors = n; | |
1501 | } | |
1502 | ||
1503 | if (!bs->drv->bdrv_co_get_block_status) { | |
1504 | *pnum = nb_sectors; | |
1505 | ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED; | |
1506 | if (bs->drv->protocol_name) { | |
1507 | ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE); | |
1508 | } | |
1509 | return ret; | |
1510 | } | |
1511 | ||
1512 | ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum); | |
1513 | if (ret < 0) { | |
1514 | *pnum = 0; | |
1515 | return ret; | |
1516 | } | |
1517 | ||
1518 | if (ret & BDRV_BLOCK_RAW) { | |
1519 | assert(ret & BDRV_BLOCK_OFFSET_VALID); | |
9a4f4c31 | 1520 | return bdrv_get_block_status(bs->file->bs, ret >> BDRV_SECTOR_BITS, |
61007b31 SH |
1521 | *pnum, pnum); |
1522 | } | |
1523 | ||
1524 | if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { | |
1525 | ret |= BDRV_BLOCK_ALLOCATED; | |
a53f1a95 | 1526 | } else { |
61007b31 SH |
1527 | if (bdrv_unallocated_blocks_are_zero(bs)) { |
1528 | ret |= BDRV_BLOCK_ZERO; | |
760e0063 KW |
1529 | } else if (bs->backing) { |
1530 | BlockDriverState *bs2 = bs->backing->bs; | |
61007b31 SH |
1531 | int64_t nb_sectors2 = bdrv_nb_sectors(bs2); |
1532 | if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) { | |
1533 | ret |= BDRV_BLOCK_ZERO; | |
1534 | } | |
1535 | } | |
1536 | } | |
1537 | ||
1538 | if (bs->file && | |
1539 | (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && | |
1540 | (ret & BDRV_BLOCK_OFFSET_VALID)) { | |
1541 | int file_pnum; | |
1542 | ||
9a4f4c31 | 1543 | ret2 = bdrv_co_get_block_status(bs->file->bs, ret >> BDRV_SECTOR_BITS, |
61007b31 SH |
1544 | *pnum, &file_pnum); |
1545 | if (ret2 >= 0) { | |
1546 | /* Ignore errors. This is just providing extra information, it | |
1547 | * is useful but not necessary. | |
1548 | */ | |
1549 | if (!file_pnum) { | |
1550 | /* !file_pnum indicates an offset at or beyond the EOF; it is | |
1551 | * perfectly valid for the format block driver to point to such | |
1552 | * offsets, so catch it and mark everything as zero */ | |
1553 | ret |= BDRV_BLOCK_ZERO; | |
1554 | } else { | |
1555 | /* Limit request to the range reported by the protocol driver */ | |
1556 | *pnum = file_pnum; | |
1557 | ret |= (ret2 & BDRV_BLOCK_ZERO); | |
1558 | } | |
1559 | } | |
1560 | } | |
1561 | ||
1562 | return ret; | |
1563 | } | |
1564 | ||
ba3f0e25 FZ |
1565 | static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs, |
1566 | BlockDriverState *base, | |
1567 | int64_t sector_num, | |
1568 | int nb_sectors, | |
1569 | int *pnum) | |
1570 | { | |
1571 | BlockDriverState *p; | |
1572 | int64_t ret = 0; | |
1573 | ||
1574 | assert(bs != base); | |
760e0063 | 1575 | for (p = bs; p != base; p = backing_bs(p)) { |
ba3f0e25 FZ |
1576 | ret = bdrv_co_get_block_status(p, sector_num, nb_sectors, pnum); |
1577 | if (ret < 0 || ret & BDRV_BLOCK_ALLOCATED) { | |
1578 | break; | |
1579 | } | |
1580 | /* [sector_num, pnum] unallocated on this layer, which could be only | |
1581 | * the first part of [sector_num, nb_sectors]. */ | |
1582 | nb_sectors = MIN(nb_sectors, *pnum); | |
1583 | } | |
1584 | return ret; | |
1585 | } | |
1586 | ||
1587 | /* Coroutine wrapper for bdrv_get_block_status_above() */ | |
1588 | static void coroutine_fn bdrv_get_block_status_above_co_entry(void *opaque) | |
61007b31 SH |
1589 | { |
1590 | BdrvCoGetBlockStatusData *data = opaque; | |
61007b31 | 1591 | |
ba3f0e25 FZ |
1592 | data->ret = bdrv_co_get_block_status_above(data->bs, data->base, |
1593 | data->sector_num, | |
1594 | data->nb_sectors, | |
1595 | data->pnum); | |
61007b31 SH |
1596 | data->done = true; |
1597 | } | |
1598 | ||
1599 | /* | |
ba3f0e25 | 1600 | * Synchronous wrapper around bdrv_co_get_block_status_above(). |
61007b31 | 1601 | * |
ba3f0e25 | 1602 | * See bdrv_co_get_block_status_above() for details. |
61007b31 | 1603 | */ |
ba3f0e25 FZ |
1604 | int64_t bdrv_get_block_status_above(BlockDriverState *bs, |
1605 | BlockDriverState *base, | |
1606 | int64_t sector_num, | |
1607 | int nb_sectors, int *pnum) | |
61007b31 SH |
1608 | { |
1609 | Coroutine *co; | |
1610 | BdrvCoGetBlockStatusData data = { | |
1611 | .bs = bs, | |
ba3f0e25 | 1612 | .base = base, |
61007b31 SH |
1613 | .sector_num = sector_num, |
1614 | .nb_sectors = nb_sectors, | |
1615 | .pnum = pnum, | |
1616 | .done = false, | |
1617 | }; | |
1618 | ||
1619 | if (qemu_in_coroutine()) { | |
1620 | /* Fast-path if already in coroutine context */ | |
ba3f0e25 | 1621 | bdrv_get_block_status_above_co_entry(&data); |
61007b31 SH |
1622 | } else { |
1623 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1624 | ||
ba3f0e25 | 1625 | co = qemu_coroutine_create(bdrv_get_block_status_above_co_entry); |
61007b31 SH |
1626 | qemu_coroutine_enter(co, &data); |
1627 | while (!data.done) { | |
1628 | aio_poll(aio_context, true); | |
1629 | } | |
1630 | } | |
1631 | return data.ret; | |
1632 | } | |
1633 | ||
ba3f0e25 FZ |
1634 | int64_t bdrv_get_block_status(BlockDriverState *bs, |
1635 | int64_t sector_num, | |
1636 | int nb_sectors, int *pnum) | |
1637 | { | |
760e0063 | 1638 | return bdrv_get_block_status_above(bs, backing_bs(bs), |
ba3f0e25 FZ |
1639 | sector_num, nb_sectors, pnum); |
1640 | } | |
1641 | ||
61007b31 SH |
1642 | int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, |
1643 | int nb_sectors, int *pnum) | |
1644 | { | |
1645 | int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum); | |
1646 | if (ret < 0) { | |
1647 | return ret; | |
1648 | } | |
1649 | return !!(ret & BDRV_BLOCK_ALLOCATED); | |
1650 | } | |
1651 | ||
1652 | /* | |
1653 | * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] | |
1654 | * | |
1655 | * Return true if the given sector is allocated in any image between | |
1656 | * BASE and TOP (inclusive). BASE can be NULL to check if the given | |
1657 | * sector is allocated in any image of the chain. Return false otherwise. | |
1658 | * | |
1659 | * 'pnum' is set to the number of sectors (including and immediately following | |
1660 | * the specified sector) that are known to be in the same | |
1661 | * allocated/unallocated state. | |
1662 | * | |
1663 | */ | |
1664 | int bdrv_is_allocated_above(BlockDriverState *top, | |
1665 | BlockDriverState *base, | |
1666 | int64_t sector_num, | |
1667 | int nb_sectors, int *pnum) | |
1668 | { | |
1669 | BlockDriverState *intermediate; | |
1670 | int ret, n = nb_sectors; | |
1671 | ||
1672 | intermediate = top; | |
1673 | while (intermediate && intermediate != base) { | |
1674 | int pnum_inter; | |
1675 | ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors, | |
1676 | &pnum_inter); | |
1677 | if (ret < 0) { | |
1678 | return ret; | |
1679 | } else if (ret) { | |
1680 | *pnum = pnum_inter; | |
1681 | return 1; | |
1682 | } | |
1683 | ||
1684 | /* | |
1685 | * [sector_num, nb_sectors] is unallocated on top but intermediate | |
1686 | * might have | |
1687 | * | |
1688 | * [sector_num+x, nr_sectors] allocated. | |
1689 | */ | |
1690 | if (n > pnum_inter && | |
1691 | (intermediate == top || | |
1692 | sector_num + pnum_inter < intermediate->total_sectors)) { | |
1693 | n = pnum_inter; | |
1694 | } | |
1695 | ||
760e0063 | 1696 | intermediate = backing_bs(intermediate); |
61007b31 SH |
1697 | } |
1698 | ||
1699 | *pnum = n; | |
1700 | return 0; | |
1701 | } | |
1702 | ||
1703 | int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, | |
1704 | const uint8_t *buf, int nb_sectors) | |
1705 | { | |
1706 | BlockDriver *drv = bs->drv; | |
1707 | int ret; | |
1708 | ||
1709 | if (!drv) { | |
1710 | return -ENOMEDIUM; | |
1711 | } | |
1712 | if (!drv->bdrv_write_compressed) { | |
1713 | return -ENOTSUP; | |
1714 | } | |
1715 | ret = bdrv_check_request(bs, sector_num, nb_sectors); | |
1716 | if (ret < 0) { | |
1717 | return ret; | |
1718 | } | |
1719 | ||
1720 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
1721 | ||
1722 | return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); | |
1723 | } | |
1724 | ||
1725 | int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, | |
1726 | int64_t pos, int size) | |
1727 | { | |
1728 | QEMUIOVector qiov; | |
1729 | struct iovec iov = { | |
1730 | .iov_base = (void *) buf, | |
1731 | .iov_len = size, | |
1732 | }; | |
1733 | ||
1734 | qemu_iovec_init_external(&qiov, &iov, 1); | |
1735 | return bdrv_writev_vmstate(bs, &qiov, pos); | |
1736 | } | |
1737 | ||
1738 | int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) | |
1739 | { | |
1740 | BlockDriver *drv = bs->drv; | |
1741 | ||
1742 | if (!drv) { | |
1743 | return -ENOMEDIUM; | |
1744 | } else if (drv->bdrv_save_vmstate) { | |
1745 | return drv->bdrv_save_vmstate(bs, qiov, pos); | |
1746 | } else if (bs->file) { | |
9a4f4c31 | 1747 | return bdrv_writev_vmstate(bs->file->bs, qiov, pos); |
61007b31 SH |
1748 | } |
1749 | ||
1750 | return -ENOTSUP; | |
1751 | } | |
1752 | ||
1753 | int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, | |
1754 | int64_t pos, int size) | |
1755 | { | |
1756 | BlockDriver *drv = bs->drv; | |
1757 | if (!drv) | |
1758 | return -ENOMEDIUM; | |
1759 | if (drv->bdrv_load_vmstate) | |
1760 | return drv->bdrv_load_vmstate(bs, buf, pos, size); | |
1761 | if (bs->file) | |
9a4f4c31 | 1762 | return bdrv_load_vmstate(bs->file->bs, buf, pos, size); |
61007b31 SH |
1763 | return -ENOTSUP; |
1764 | } | |
1765 | ||
1766 | /**************************************************************/ | |
1767 | /* async I/Os */ | |
1768 | ||
1769 | BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, | |
1770 | QEMUIOVector *qiov, int nb_sectors, | |
1771 | BlockCompletionFunc *cb, void *opaque) | |
1772 | { | |
1773 | trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); | |
1774 | ||
1775 | return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, | |
1776 | cb, opaque, false); | |
1777 | } | |
1778 | ||
1779 | BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, | |
1780 | QEMUIOVector *qiov, int nb_sectors, | |
1781 | BlockCompletionFunc *cb, void *opaque) | |
1782 | { | |
1783 | trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); | |
1784 | ||
1785 | return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, | |
1786 | cb, opaque, true); | |
1787 | } | |
1788 | ||
1789 | BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, | |
1790 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags, | |
1791 | BlockCompletionFunc *cb, void *opaque) | |
1792 | { | |
1793 | trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque); | |
1794 | ||
1795 | return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors, | |
1796 | BDRV_REQ_ZERO_WRITE | flags, | |
1797 | cb, opaque, true); | |
1798 | } | |
1799 | ||
1800 | ||
1801 | typedef struct MultiwriteCB { | |
1802 | int error; | |
1803 | int num_requests; | |
1804 | int num_callbacks; | |
1805 | struct { | |
1806 | BlockCompletionFunc *cb; | |
1807 | void *opaque; | |
1808 | QEMUIOVector *free_qiov; | |
1809 | } callbacks[]; | |
1810 | } MultiwriteCB; | |
1811 | ||
1812 | static void multiwrite_user_cb(MultiwriteCB *mcb) | |
1813 | { | |
1814 | int i; | |
1815 | ||
1816 | for (i = 0; i < mcb->num_callbacks; i++) { | |
1817 | mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); | |
1818 | if (mcb->callbacks[i].free_qiov) { | |
1819 | qemu_iovec_destroy(mcb->callbacks[i].free_qiov); | |
1820 | } | |
1821 | g_free(mcb->callbacks[i].free_qiov); | |
1822 | } | |
1823 | } | |
1824 | ||
1825 | static void multiwrite_cb(void *opaque, int ret) | |
1826 | { | |
1827 | MultiwriteCB *mcb = opaque; | |
1828 | ||
1829 | trace_multiwrite_cb(mcb, ret); | |
1830 | ||
1831 | if (ret < 0 && !mcb->error) { | |
1832 | mcb->error = ret; | |
1833 | } | |
1834 | ||
1835 | mcb->num_requests--; | |
1836 | if (mcb->num_requests == 0) { | |
1837 | multiwrite_user_cb(mcb); | |
1838 | g_free(mcb); | |
1839 | } | |
1840 | } | |
1841 | ||
1842 | static int multiwrite_req_compare(const void *a, const void *b) | |
1843 | { | |
1844 | const BlockRequest *req1 = a, *req2 = b; | |
1845 | ||
1846 | /* | |
1847 | * Note that we can't simply subtract req2->sector from req1->sector | |
1848 | * here as that could overflow the return value. | |
1849 | */ | |
1850 | if (req1->sector > req2->sector) { | |
1851 | return 1; | |
1852 | } else if (req1->sector < req2->sector) { | |
1853 | return -1; | |
1854 | } else { | |
1855 | return 0; | |
1856 | } | |
1857 | } | |
1858 | ||
1859 | /* | |
1860 | * Takes a bunch of requests and tries to merge them. Returns the number of | |
1861 | * requests that remain after merging. | |
1862 | */ | |
1863 | static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, | |
1864 | int num_reqs, MultiwriteCB *mcb) | |
1865 | { | |
1866 | int i, outidx; | |
1867 | ||
1868 | // Sort requests by start sector | |
1869 | qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); | |
1870 | ||
1871 | // Check if adjacent requests touch the same clusters. If so, combine them, | |
1872 | // filling up gaps with zero sectors. | |
1873 | outidx = 0; | |
1874 | for (i = 1; i < num_reqs; i++) { | |
1875 | int merge = 0; | |
1876 | int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; | |
1877 | ||
1878 | // Handle exactly sequential writes and overlapping writes. | |
1879 | if (reqs[i].sector <= oldreq_last) { | |
1880 | merge = 1; | |
1881 | } | |
1882 | ||
1883 | if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { | |
1884 | merge = 0; | |
1885 | } | |
1886 | ||
1887 | if (bs->bl.max_transfer_length && reqs[outidx].nb_sectors + | |
1888 | reqs[i].nb_sectors > bs->bl.max_transfer_length) { | |
1889 | merge = 0; | |
1890 | } | |
1891 | ||
1892 | if (merge) { | |
1893 | size_t size; | |
1894 | QEMUIOVector *qiov = g_malloc0(sizeof(*qiov)); | |
1895 | qemu_iovec_init(qiov, | |
1896 | reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); | |
1897 | ||
1898 | // Add the first request to the merged one. If the requests are | |
1899 | // overlapping, drop the last sectors of the first request. | |
1900 | size = (reqs[i].sector - reqs[outidx].sector) << 9; | |
1901 | qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); | |
1902 | ||
1903 | // We should need to add any zeros between the two requests | |
1904 | assert (reqs[i].sector <= oldreq_last); | |
1905 | ||
1906 | // Add the second request | |
1907 | qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); | |
1908 | ||
1909 | // Add tail of first request, if necessary | |
1910 | if (qiov->size < reqs[outidx].qiov->size) { | |
1911 | qemu_iovec_concat(qiov, reqs[outidx].qiov, qiov->size, | |
1912 | reqs[outidx].qiov->size - qiov->size); | |
1913 | } | |
1914 | ||
1915 | reqs[outidx].nb_sectors = qiov->size >> 9; | |
1916 | reqs[outidx].qiov = qiov; | |
1917 | ||
1918 | mcb->callbacks[i].free_qiov = reqs[outidx].qiov; | |
1919 | } else { | |
1920 | outidx++; | |
1921 | reqs[outidx].sector = reqs[i].sector; | |
1922 | reqs[outidx].nb_sectors = reqs[i].nb_sectors; | |
1923 | reqs[outidx].qiov = reqs[i].qiov; | |
1924 | } | |
1925 | } | |
1926 | ||
7f0e9da6 HR |
1927 | if (bs->blk) { |
1928 | block_acct_merge_done(blk_get_stats(bs->blk), BLOCK_ACCT_WRITE, | |
1929 | num_reqs - outidx - 1); | |
1930 | } | |
61007b31 SH |
1931 | |
1932 | return outidx + 1; | |
1933 | } | |
1934 | ||
1935 | /* | |
1936 | * Submit multiple AIO write requests at once. | |
1937 | * | |
1938 | * On success, the function returns 0 and all requests in the reqs array have | |
1939 | * been submitted. In error case this function returns -1, and any of the | |
1940 | * requests may or may not be submitted yet. In particular, this means that the | |
1941 | * callback will be called for some of the requests, for others it won't. The | |
1942 | * caller must check the error field of the BlockRequest to wait for the right | |
1943 | * callbacks (if error != 0, no callback will be called). | |
1944 | * | |
1945 | * The implementation may modify the contents of the reqs array, e.g. to merge | |
1946 | * requests. However, the fields opaque and error are left unmodified as they | |
1947 | * are used to signal failure for a single request to the caller. | |
1948 | */ | |
1949 | int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) | |
1950 | { | |
1951 | MultiwriteCB *mcb; | |
1952 | int i; | |
1953 | ||
1954 | /* don't submit writes if we don't have a medium */ | |
1955 | if (bs->drv == NULL) { | |
1956 | for (i = 0; i < num_reqs; i++) { | |
1957 | reqs[i].error = -ENOMEDIUM; | |
1958 | } | |
1959 | return -1; | |
1960 | } | |
1961 | ||
1962 | if (num_reqs == 0) { | |
1963 | return 0; | |
1964 | } | |
1965 | ||
1966 | // Create MultiwriteCB structure | |
1967 | mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); | |
1968 | mcb->num_requests = 0; | |
1969 | mcb->num_callbacks = num_reqs; | |
1970 | ||
1971 | for (i = 0; i < num_reqs; i++) { | |
1972 | mcb->callbacks[i].cb = reqs[i].cb; | |
1973 | mcb->callbacks[i].opaque = reqs[i].opaque; | |
1974 | } | |
1975 | ||
1976 | // Check for mergable requests | |
1977 | num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); | |
1978 | ||
1979 | trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); | |
1980 | ||
1981 | /* Run the aio requests. */ | |
1982 | mcb->num_requests = num_reqs; | |
1983 | for (i = 0; i < num_reqs; i++) { | |
1984 | bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov, | |
1985 | reqs[i].nb_sectors, reqs[i].flags, | |
1986 | multiwrite_cb, mcb, | |
1987 | true); | |
1988 | } | |
1989 | ||
1990 | return 0; | |
1991 | } | |
1992 | ||
1993 | void bdrv_aio_cancel(BlockAIOCB *acb) | |
1994 | { | |
1995 | qemu_aio_ref(acb); | |
1996 | bdrv_aio_cancel_async(acb); | |
1997 | while (acb->refcnt > 1) { | |
1998 | if (acb->aiocb_info->get_aio_context) { | |
1999 | aio_poll(acb->aiocb_info->get_aio_context(acb), true); | |
2000 | } else if (acb->bs) { | |
2001 | aio_poll(bdrv_get_aio_context(acb->bs), true); | |
2002 | } else { | |
2003 | abort(); | |
2004 | } | |
2005 | } | |
2006 | qemu_aio_unref(acb); | |
2007 | } | |
2008 | ||
2009 | /* Async version of aio cancel. The caller is not blocked if the acb implements | |
2010 | * cancel_async, otherwise we do nothing and let the request normally complete. | |
2011 | * In either case the completion callback must be called. */ | |
2012 | void bdrv_aio_cancel_async(BlockAIOCB *acb) | |
2013 | { | |
2014 | if (acb->aiocb_info->cancel_async) { | |
2015 | acb->aiocb_info->cancel_async(acb); | |
2016 | } | |
2017 | } | |
2018 | ||
2019 | /**************************************************************/ | |
2020 | /* async block device emulation */ | |
2021 | ||
2022 | typedef struct BlockAIOCBSync { | |
2023 | BlockAIOCB common; | |
2024 | QEMUBH *bh; | |
2025 | int ret; | |
2026 | /* vector translation state */ | |
2027 | QEMUIOVector *qiov; | |
2028 | uint8_t *bounce; | |
2029 | int is_write; | |
2030 | } BlockAIOCBSync; | |
2031 | ||
2032 | static const AIOCBInfo bdrv_em_aiocb_info = { | |
2033 | .aiocb_size = sizeof(BlockAIOCBSync), | |
2034 | }; | |
2035 | ||
2036 | static void bdrv_aio_bh_cb(void *opaque) | |
2037 | { | |
2038 | BlockAIOCBSync *acb = opaque; | |
2039 | ||
2040 | if (!acb->is_write && acb->ret >= 0) { | |
2041 | qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); | |
2042 | } | |
2043 | qemu_vfree(acb->bounce); | |
2044 | acb->common.cb(acb->common.opaque, acb->ret); | |
2045 | qemu_bh_delete(acb->bh); | |
2046 | acb->bh = NULL; | |
2047 | qemu_aio_unref(acb); | |
2048 | } | |
2049 | ||
2050 | static BlockAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, | |
2051 | int64_t sector_num, | |
2052 | QEMUIOVector *qiov, | |
2053 | int nb_sectors, | |
2054 | BlockCompletionFunc *cb, | |
2055 | void *opaque, | |
2056 | int is_write) | |
2057 | ||
2058 | { | |
2059 | BlockAIOCBSync *acb; | |
2060 | ||
2061 | acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque); | |
2062 | acb->is_write = is_write; | |
2063 | acb->qiov = qiov; | |
2064 | acb->bounce = qemu_try_blockalign(bs, qiov->size); | |
2065 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb); | |
2066 | ||
2067 | if (acb->bounce == NULL) { | |
2068 | acb->ret = -ENOMEM; | |
2069 | } else if (is_write) { | |
2070 | qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); | |
2071 | acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); | |
2072 | } else { | |
2073 | acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); | |
2074 | } | |
2075 | ||
2076 | qemu_bh_schedule(acb->bh); | |
2077 | ||
2078 | return &acb->common; | |
2079 | } | |
2080 | ||
2081 | static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, | |
2082 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
2083 | BlockCompletionFunc *cb, void *opaque) | |
2084 | { | |
2085 | return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); | |
2086 | } | |
2087 | ||
2088 | static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, | |
2089 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
2090 | BlockCompletionFunc *cb, void *opaque) | |
2091 | { | |
2092 | return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); | |
2093 | } | |
2094 | ||
2095 | ||
2096 | typedef struct BlockAIOCBCoroutine { | |
2097 | BlockAIOCB common; | |
2098 | BlockRequest req; | |
2099 | bool is_write; | |
2100 | bool need_bh; | |
2101 | bool *done; | |
2102 | QEMUBH* bh; | |
2103 | } BlockAIOCBCoroutine; | |
2104 | ||
2105 | static const AIOCBInfo bdrv_em_co_aiocb_info = { | |
2106 | .aiocb_size = sizeof(BlockAIOCBCoroutine), | |
2107 | }; | |
2108 | ||
2109 | static void bdrv_co_complete(BlockAIOCBCoroutine *acb) | |
2110 | { | |
2111 | if (!acb->need_bh) { | |
2112 | acb->common.cb(acb->common.opaque, acb->req.error); | |
2113 | qemu_aio_unref(acb); | |
2114 | } | |
2115 | } | |
2116 | ||
2117 | static void bdrv_co_em_bh(void *opaque) | |
2118 | { | |
2119 | BlockAIOCBCoroutine *acb = opaque; | |
2120 | ||
2121 | assert(!acb->need_bh); | |
2122 | qemu_bh_delete(acb->bh); | |
2123 | bdrv_co_complete(acb); | |
2124 | } | |
2125 | ||
2126 | static void bdrv_co_maybe_schedule_bh(BlockAIOCBCoroutine *acb) | |
2127 | { | |
2128 | acb->need_bh = false; | |
2129 | if (acb->req.error != -EINPROGRESS) { | |
2130 | BlockDriverState *bs = acb->common.bs; | |
2131 | ||
2132 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); | |
2133 | qemu_bh_schedule(acb->bh); | |
2134 | } | |
2135 | } | |
2136 | ||
2137 | /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */ | |
2138 | static void coroutine_fn bdrv_co_do_rw(void *opaque) | |
2139 | { | |
2140 | BlockAIOCBCoroutine *acb = opaque; | |
2141 | BlockDriverState *bs = acb->common.bs; | |
2142 | ||
2143 | if (!acb->is_write) { | |
2144 | acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, | |
2145 | acb->req.nb_sectors, acb->req.qiov, acb->req.flags); | |
2146 | } else { | |
2147 | acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, | |
2148 | acb->req.nb_sectors, acb->req.qiov, acb->req.flags); | |
2149 | } | |
2150 | ||
2151 | bdrv_co_complete(acb); | |
2152 | } | |
2153 | ||
2154 | static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, | |
2155 | int64_t sector_num, | |
2156 | QEMUIOVector *qiov, | |
2157 | int nb_sectors, | |
2158 | BdrvRequestFlags flags, | |
2159 | BlockCompletionFunc *cb, | |
2160 | void *opaque, | |
2161 | bool is_write) | |
2162 | { | |
2163 | Coroutine *co; | |
2164 | BlockAIOCBCoroutine *acb; | |
2165 | ||
2166 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
2167 | acb->need_bh = true; | |
2168 | acb->req.error = -EINPROGRESS; | |
2169 | acb->req.sector = sector_num; | |
2170 | acb->req.nb_sectors = nb_sectors; | |
2171 | acb->req.qiov = qiov; | |
2172 | acb->req.flags = flags; | |
2173 | acb->is_write = is_write; | |
2174 | ||
2175 | co = qemu_coroutine_create(bdrv_co_do_rw); | |
2176 | qemu_coroutine_enter(co, acb); | |
2177 | ||
2178 | bdrv_co_maybe_schedule_bh(acb); | |
2179 | return &acb->common; | |
2180 | } | |
2181 | ||
2182 | static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) | |
2183 | { | |
2184 | BlockAIOCBCoroutine *acb = opaque; | |
2185 | BlockDriverState *bs = acb->common.bs; | |
2186 | ||
2187 | acb->req.error = bdrv_co_flush(bs); | |
2188 | bdrv_co_complete(acb); | |
2189 | } | |
2190 | ||
2191 | BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs, | |
2192 | BlockCompletionFunc *cb, void *opaque) | |
2193 | { | |
2194 | trace_bdrv_aio_flush(bs, opaque); | |
2195 | ||
2196 | Coroutine *co; | |
2197 | BlockAIOCBCoroutine *acb; | |
2198 | ||
2199 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
2200 | acb->need_bh = true; | |
2201 | acb->req.error = -EINPROGRESS; | |
2202 | ||
2203 | co = qemu_coroutine_create(bdrv_aio_flush_co_entry); | |
2204 | qemu_coroutine_enter(co, acb); | |
2205 | ||
2206 | bdrv_co_maybe_schedule_bh(acb); | |
2207 | return &acb->common; | |
2208 | } | |
2209 | ||
2210 | static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) | |
2211 | { | |
2212 | BlockAIOCBCoroutine *acb = opaque; | |
2213 | BlockDriverState *bs = acb->common.bs; | |
2214 | ||
2215 | acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); | |
2216 | bdrv_co_complete(acb); | |
2217 | } | |
2218 | ||
2219 | BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs, | |
2220 | int64_t sector_num, int nb_sectors, | |
2221 | BlockCompletionFunc *cb, void *opaque) | |
2222 | { | |
2223 | Coroutine *co; | |
2224 | BlockAIOCBCoroutine *acb; | |
2225 | ||
2226 | trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); | |
2227 | ||
2228 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
2229 | acb->need_bh = true; | |
2230 | acb->req.error = -EINPROGRESS; | |
2231 | acb->req.sector = sector_num; | |
2232 | acb->req.nb_sectors = nb_sectors; | |
2233 | co = qemu_coroutine_create(bdrv_aio_discard_co_entry); | |
2234 | qemu_coroutine_enter(co, acb); | |
2235 | ||
2236 | bdrv_co_maybe_schedule_bh(acb); | |
2237 | return &acb->common; | |
2238 | } | |
2239 | ||
2240 | void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs, | |
2241 | BlockCompletionFunc *cb, void *opaque) | |
2242 | { | |
2243 | BlockAIOCB *acb; | |
2244 | ||
c84b3192 | 2245 | acb = g_malloc(aiocb_info->aiocb_size); |
61007b31 SH |
2246 | acb->aiocb_info = aiocb_info; |
2247 | acb->bs = bs; | |
2248 | acb->cb = cb; | |
2249 | acb->opaque = opaque; | |
2250 | acb->refcnt = 1; | |
2251 | return acb; | |
2252 | } | |
2253 | ||
2254 | void qemu_aio_ref(void *p) | |
2255 | { | |
2256 | BlockAIOCB *acb = p; | |
2257 | acb->refcnt++; | |
2258 | } | |
2259 | ||
2260 | void qemu_aio_unref(void *p) | |
2261 | { | |
2262 | BlockAIOCB *acb = p; | |
2263 | assert(acb->refcnt > 0); | |
2264 | if (--acb->refcnt == 0) { | |
c84b3192 | 2265 | g_free(acb); |
61007b31 SH |
2266 | } |
2267 | } | |
2268 | ||
2269 | /**************************************************************/ | |
2270 | /* Coroutine block device emulation */ | |
2271 | ||
2272 | typedef struct CoroutineIOCompletion { | |
2273 | Coroutine *coroutine; | |
2274 | int ret; | |
2275 | } CoroutineIOCompletion; | |
2276 | ||
2277 | static void bdrv_co_io_em_complete(void *opaque, int ret) | |
2278 | { | |
2279 | CoroutineIOCompletion *co = opaque; | |
2280 | ||
2281 | co->ret = ret; | |
2282 | qemu_coroutine_enter(co->coroutine, NULL); | |
2283 | } | |
2284 | ||
2285 | static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, | |
2286 | int nb_sectors, QEMUIOVector *iov, | |
2287 | bool is_write) | |
2288 | { | |
2289 | CoroutineIOCompletion co = { | |
2290 | .coroutine = qemu_coroutine_self(), | |
2291 | }; | |
2292 | BlockAIOCB *acb; | |
2293 | ||
2294 | if (is_write) { | |
2295 | acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, | |
2296 | bdrv_co_io_em_complete, &co); | |
2297 | } else { | |
2298 | acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, | |
2299 | bdrv_co_io_em_complete, &co); | |
2300 | } | |
2301 | ||
2302 | trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); | |
2303 | if (!acb) { | |
2304 | return -EIO; | |
2305 | } | |
2306 | qemu_coroutine_yield(); | |
2307 | ||
2308 | return co.ret; | |
2309 | } | |
2310 | ||
2311 | static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, | |
2312 | int64_t sector_num, int nb_sectors, | |
2313 | QEMUIOVector *iov) | |
2314 | { | |
2315 | return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); | |
2316 | } | |
2317 | ||
2318 | static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, | |
2319 | int64_t sector_num, int nb_sectors, | |
2320 | QEMUIOVector *iov) | |
2321 | { | |
2322 | return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); | |
2323 | } | |
2324 | ||
2325 | static void coroutine_fn bdrv_flush_co_entry(void *opaque) | |
2326 | { | |
2327 | RwCo *rwco = opaque; | |
2328 | ||
2329 | rwco->ret = bdrv_co_flush(rwco->bs); | |
2330 | } | |
2331 | ||
2332 | int coroutine_fn bdrv_co_flush(BlockDriverState *bs) | |
2333 | { | |
2334 | int ret; | |
cdb5e315 | 2335 | BdrvTrackedRequest req; |
61007b31 | 2336 | |
1b6bc94d DA |
2337 | if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || |
2338 | bdrv_is_sg(bs)) { | |
61007b31 SH |
2339 | return 0; |
2340 | } | |
2341 | ||
cdb5e315 | 2342 | tracked_request_begin(&req, bs, 0, 0, BDRV_TRACKED_FLUSH); |
61007b31 SH |
2343 | /* Write back cached data to the OS even with cache=unsafe */ |
2344 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); | |
2345 | if (bs->drv->bdrv_co_flush_to_os) { | |
2346 | ret = bs->drv->bdrv_co_flush_to_os(bs); | |
2347 | if (ret < 0) { | |
cdb5e315 | 2348 | goto out; |
61007b31 SH |
2349 | } |
2350 | } | |
2351 | ||
2352 | /* But don't actually force it to the disk with cache=unsafe */ | |
2353 | if (bs->open_flags & BDRV_O_NO_FLUSH) { | |
2354 | goto flush_parent; | |
2355 | } | |
2356 | ||
2357 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); | |
2358 | if (bs->drv->bdrv_co_flush_to_disk) { | |
2359 | ret = bs->drv->bdrv_co_flush_to_disk(bs); | |
2360 | } else if (bs->drv->bdrv_aio_flush) { | |
2361 | BlockAIOCB *acb; | |
2362 | CoroutineIOCompletion co = { | |
2363 | .coroutine = qemu_coroutine_self(), | |
2364 | }; | |
2365 | ||
2366 | acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); | |
2367 | if (acb == NULL) { | |
2368 | ret = -EIO; | |
2369 | } else { | |
2370 | qemu_coroutine_yield(); | |
2371 | ret = co.ret; | |
2372 | } | |
2373 | } else { | |
2374 | /* | |
2375 | * Some block drivers always operate in either writethrough or unsafe | |
2376 | * mode and don't support bdrv_flush therefore. Usually qemu doesn't | |
2377 | * know how the server works (because the behaviour is hardcoded or | |
2378 | * depends on server-side configuration), so we can't ensure that | |
2379 | * everything is safe on disk. Returning an error doesn't work because | |
2380 | * that would break guests even if the server operates in writethrough | |
2381 | * mode. | |
2382 | * | |
2383 | * Let's hope the user knows what he's doing. | |
2384 | */ | |
2385 | ret = 0; | |
2386 | } | |
2387 | if (ret < 0) { | |
cdb5e315 | 2388 | goto out; |
61007b31 SH |
2389 | } |
2390 | ||
2391 | /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH | |
2392 | * in the case of cache=unsafe, so there are no useless flushes. | |
2393 | */ | |
2394 | flush_parent: | |
cdb5e315 FZ |
2395 | ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0; |
2396 | out: | |
2397 | tracked_request_end(&req); | |
2398 | return ret; | |
61007b31 SH |
2399 | } |
2400 | ||
2401 | int bdrv_flush(BlockDriverState *bs) | |
2402 | { | |
2403 | Coroutine *co; | |
2404 | RwCo rwco = { | |
2405 | .bs = bs, | |
2406 | .ret = NOT_DONE, | |
2407 | }; | |
2408 | ||
2409 | if (qemu_in_coroutine()) { | |
2410 | /* Fast-path if already in coroutine context */ | |
2411 | bdrv_flush_co_entry(&rwco); | |
2412 | } else { | |
2413 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2414 | ||
2415 | co = qemu_coroutine_create(bdrv_flush_co_entry); | |
2416 | qemu_coroutine_enter(co, &rwco); | |
2417 | while (rwco.ret == NOT_DONE) { | |
2418 | aio_poll(aio_context, true); | |
2419 | } | |
2420 | } | |
2421 | ||
2422 | return rwco.ret; | |
2423 | } | |
2424 | ||
2425 | typedef struct DiscardCo { | |
2426 | BlockDriverState *bs; | |
2427 | int64_t sector_num; | |
2428 | int nb_sectors; | |
2429 | int ret; | |
2430 | } DiscardCo; | |
2431 | static void coroutine_fn bdrv_discard_co_entry(void *opaque) | |
2432 | { | |
2433 | DiscardCo *rwco = opaque; | |
2434 | ||
2435 | rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); | |
2436 | } | |
2437 | ||
2438 | int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, | |
2439 | int nb_sectors) | |
2440 | { | |
b1066c87 | 2441 | BdrvTrackedRequest req; |
61007b31 SH |
2442 | int max_discard, ret; |
2443 | ||
2444 | if (!bs->drv) { | |
2445 | return -ENOMEDIUM; | |
2446 | } | |
2447 | ||
2448 | ret = bdrv_check_request(bs, sector_num, nb_sectors); | |
2449 | if (ret < 0) { | |
2450 | return ret; | |
2451 | } else if (bs->read_only) { | |
eaf5fe2d | 2452 | return -EPERM; |
61007b31 SH |
2453 | } |
2454 | ||
61007b31 SH |
2455 | /* Do nothing if disabled. */ |
2456 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
2457 | return 0; | |
2458 | } | |
2459 | ||
2460 | if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) { | |
2461 | return 0; | |
2462 | } | |
2463 | ||
b1066c87 FZ |
2464 | tracked_request_begin(&req, bs, sector_num, nb_sectors, |
2465 | BDRV_TRACKED_DISCARD); | |
50824995 FZ |
2466 | bdrv_set_dirty(bs, sector_num, nb_sectors); |
2467 | ||
61007b31 SH |
2468 | max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS); |
2469 | while (nb_sectors > 0) { | |
2470 | int ret; | |
2471 | int num = nb_sectors; | |
2472 | ||
2473 | /* align request */ | |
2474 | if (bs->bl.discard_alignment && | |
2475 | num >= bs->bl.discard_alignment && | |
2476 | sector_num % bs->bl.discard_alignment) { | |
2477 | if (num > bs->bl.discard_alignment) { | |
2478 | num = bs->bl.discard_alignment; | |
2479 | } | |
2480 | num -= sector_num % bs->bl.discard_alignment; | |
2481 | } | |
2482 | ||
2483 | /* limit request size */ | |
2484 | if (num > max_discard) { | |
2485 | num = max_discard; | |
2486 | } | |
2487 | ||
2488 | if (bs->drv->bdrv_co_discard) { | |
2489 | ret = bs->drv->bdrv_co_discard(bs, sector_num, num); | |
2490 | } else { | |
2491 | BlockAIOCB *acb; | |
2492 | CoroutineIOCompletion co = { | |
2493 | .coroutine = qemu_coroutine_self(), | |
2494 | }; | |
2495 | ||
2496 | acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, | |
2497 | bdrv_co_io_em_complete, &co); | |
2498 | if (acb == NULL) { | |
b1066c87 FZ |
2499 | ret = -EIO; |
2500 | goto out; | |
61007b31 SH |
2501 | } else { |
2502 | qemu_coroutine_yield(); | |
2503 | ret = co.ret; | |
2504 | } | |
2505 | } | |
2506 | if (ret && ret != -ENOTSUP) { | |
b1066c87 | 2507 | goto out; |
61007b31 SH |
2508 | } |
2509 | ||
2510 | sector_num += num; | |
2511 | nb_sectors -= num; | |
2512 | } | |
b1066c87 FZ |
2513 | ret = 0; |
2514 | out: | |
2515 | tracked_request_end(&req); | |
2516 | return ret; | |
61007b31 SH |
2517 | } |
2518 | ||
2519 | int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) | |
2520 | { | |
2521 | Coroutine *co; | |
2522 | DiscardCo rwco = { | |
2523 | .bs = bs, | |
2524 | .sector_num = sector_num, | |
2525 | .nb_sectors = nb_sectors, | |
2526 | .ret = NOT_DONE, | |
2527 | }; | |
2528 | ||
2529 | if (qemu_in_coroutine()) { | |
2530 | /* Fast-path if already in coroutine context */ | |
2531 | bdrv_discard_co_entry(&rwco); | |
2532 | } else { | |
2533 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2534 | ||
2535 | co = qemu_coroutine_create(bdrv_discard_co_entry); | |
2536 | qemu_coroutine_enter(co, &rwco); | |
2537 | while (rwco.ret == NOT_DONE) { | |
2538 | aio_poll(aio_context, true); | |
2539 | } | |
2540 | } | |
2541 | ||
2542 | return rwco.ret; | |
2543 | } | |
2544 | ||
5c5ae76a FZ |
2545 | typedef struct { |
2546 | CoroutineIOCompletion *co; | |
2547 | QEMUBH *bh; | |
2548 | } BdrvIoctlCompletionData; | |
61007b31 | 2549 | |
5c5ae76a FZ |
2550 | static void bdrv_ioctl_bh_cb(void *opaque) |
2551 | { | |
2552 | BdrvIoctlCompletionData *data = opaque; | |
2553 | ||
2554 | bdrv_co_io_em_complete(data->co, -ENOTSUP); | |
2555 | qemu_bh_delete(data->bh); | |
2556 | } | |
2557 | ||
2558 | static int bdrv_co_do_ioctl(BlockDriverState *bs, int req, void *buf) | |
61007b31 SH |
2559 | { |
2560 | BlockDriver *drv = bs->drv; | |
5c5ae76a FZ |
2561 | BdrvTrackedRequest tracked_req; |
2562 | CoroutineIOCompletion co = { | |
2563 | .coroutine = qemu_coroutine_self(), | |
2564 | }; | |
2565 | BlockAIOCB *acb; | |
61007b31 | 2566 | |
5c5ae76a FZ |
2567 | tracked_request_begin(&tracked_req, bs, 0, 0, BDRV_TRACKED_IOCTL); |
2568 | if (!drv || !drv->bdrv_aio_ioctl) { | |
2569 | co.ret = -ENOTSUP; | |
2570 | goto out; | |
2571 | } | |
2572 | ||
2573 | acb = drv->bdrv_aio_ioctl(bs, req, buf, bdrv_co_io_em_complete, &co); | |
2574 | if (!acb) { | |
2575 | BdrvIoctlCompletionData *data = g_new(BdrvIoctlCompletionData, 1); | |
2576 | data->bh = aio_bh_new(bdrv_get_aio_context(bs), | |
2577 | bdrv_ioctl_bh_cb, data); | |
2578 | data->co = &co; | |
2579 | qemu_bh_schedule(data->bh); | |
2580 | } | |
2581 | qemu_coroutine_yield(); | |
2582 | out: | |
2583 | tracked_request_end(&tracked_req); | |
2584 | return co.ret; | |
2585 | } | |
2586 | ||
2587 | typedef struct { | |
2588 | BlockDriverState *bs; | |
2589 | int req; | |
2590 | void *buf; | |
2591 | int ret; | |
2592 | } BdrvIoctlCoData; | |
2593 | ||
2594 | static void coroutine_fn bdrv_co_ioctl_entry(void *opaque) | |
2595 | { | |
2596 | BdrvIoctlCoData *data = opaque; | |
2597 | data->ret = bdrv_co_do_ioctl(data->bs, data->req, data->buf); | |
2598 | } | |
2599 | ||
2600 | /* needed for generic scsi interface */ | |
2601 | int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) | |
2602 | { | |
2603 | BdrvIoctlCoData data = { | |
2604 | .bs = bs, | |
2605 | .req = req, | |
2606 | .buf = buf, | |
2607 | .ret = -EINPROGRESS, | |
2608 | }; | |
2609 | ||
2610 | if (qemu_in_coroutine()) { | |
2611 | /* Fast-path if already in coroutine context */ | |
2612 | bdrv_co_ioctl_entry(&data); | |
2613 | } else { | |
2614 | Coroutine *co = qemu_coroutine_create(bdrv_co_ioctl_entry); | |
2615 | qemu_coroutine_enter(co, &data); | |
2616 | } | |
2617 | while (data.ret == -EINPROGRESS) { | |
2618 | aio_poll(bdrv_get_aio_context(bs), true); | |
2619 | } | |
2620 | return data.ret; | |
2621 | } | |
2622 | ||
2623 | static void coroutine_fn bdrv_co_aio_ioctl_entry(void *opaque) | |
2624 | { | |
2625 | BlockAIOCBCoroutine *acb = opaque; | |
2626 | acb->req.error = bdrv_co_do_ioctl(acb->common.bs, | |
2627 | acb->req.req, acb->req.buf); | |
2628 | bdrv_co_complete(acb); | |
61007b31 SH |
2629 | } |
2630 | ||
2631 | BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, | |
2632 | unsigned long int req, void *buf, | |
2633 | BlockCompletionFunc *cb, void *opaque) | |
2634 | { | |
5c5ae76a FZ |
2635 | BlockAIOCBCoroutine *acb = qemu_aio_get(&bdrv_em_co_aiocb_info, |
2636 | bs, cb, opaque); | |
2637 | Coroutine *co; | |
61007b31 | 2638 | |
5c5ae76a FZ |
2639 | acb->need_bh = true; |
2640 | acb->req.error = -EINPROGRESS; | |
2641 | acb->req.req = req; | |
2642 | acb->req.buf = buf; | |
2643 | co = qemu_coroutine_create(bdrv_co_aio_ioctl_entry); | |
2644 | qemu_coroutine_enter(co, acb); | |
2645 | ||
2646 | bdrv_co_maybe_schedule_bh(acb); | |
2647 | return &acb->common; | |
61007b31 SH |
2648 | } |
2649 | ||
2650 | void *qemu_blockalign(BlockDriverState *bs, size_t size) | |
2651 | { | |
2652 | return qemu_memalign(bdrv_opt_mem_align(bs), size); | |
2653 | } | |
2654 | ||
2655 | void *qemu_blockalign0(BlockDriverState *bs, size_t size) | |
2656 | { | |
2657 | return memset(qemu_blockalign(bs, size), 0, size); | |
2658 | } | |
2659 | ||
2660 | void *qemu_try_blockalign(BlockDriverState *bs, size_t size) | |
2661 | { | |
2662 | size_t align = bdrv_opt_mem_align(bs); | |
2663 | ||
2664 | /* Ensure that NULL is never returned on success */ | |
2665 | assert(align > 0); | |
2666 | if (size == 0) { | |
2667 | size = align; | |
2668 | } | |
2669 | ||
2670 | return qemu_try_memalign(align, size); | |
2671 | } | |
2672 | ||
2673 | void *qemu_try_blockalign0(BlockDriverState *bs, size_t size) | |
2674 | { | |
2675 | void *mem = qemu_try_blockalign(bs, size); | |
2676 | ||
2677 | if (mem) { | |
2678 | memset(mem, 0, size); | |
2679 | } | |
2680 | ||
2681 | return mem; | |
2682 | } | |
2683 | ||
2684 | /* | |
2685 | * Check if all memory in this vector is sector aligned. | |
2686 | */ | |
2687 | bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) | |
2688 | { | |
2689 | int i; | |
4196d2f0 | 2690 | size_t alignment = bdrv_min_mem_align(bs); |
61007b31 SH |
2691 | |
2692 | for (i = 0; i < qiov->niov; i++) { | |
2693 | if ((uintptr_t) qiov->iov[i].iov_base % alignment) { | |
2694 | return false; | |
2695 | } | |
2696 | if (qiov->iov[i].iov_len % alignment) { | |
2697 | return false; | |
2698 | } | |
2699 | } | |
2700 | ||
2701 | return true; | |
2702 | } | |
2703 | ||
2704 | void bdrv_add_before_write_notifier(BlockDriverState *bs, | |
2705 | NotifierWithReturn *notifier) | |
2706 | { | |
2707 | notifier_with_return_list_add(&bs->before_write_notifiers, notifier); | |
2708 | } | |
2709 | ||
2710 | void bdrv_io_plug(BlockDriverState *bs) | |
2711 | { | |
2712 | BlockDriver *drv = bs->drv; | |
2713 | if (drv && drv->bdrv_io_plug) { | |
2714 | drv->bdrv_io_plug(bs); | |
2715 | } else if (bs->file) { | |
9a4f4c31 | 2716 | bdrv_io_plug(bs->file->bs); |
61007b31 SH |
2717 | } |
2718 | } | |
2719 | ||
2720 | void bdrv_io_unplug(BlockDriverState *bs) | |
2721 | { | |
2722 | BlockDriver *drv = bs->drv; | |
2723 | if (drv && drv->bdrv_io_unplug) { | |
2724 | drv->bdrv_io_unplug(bs); | |
2725 | } else if (bs->file) { | |
9a4f4c31 | 2726 | bdrv_io_unplug(bs->file->bs); |
61007b31 SH |
2727 | } |
2728 | } | |
2729 | ||
2730 | void bdrv_flush_io_queue(BlockDriverState *bs) | |
2731 | { | |
2732 | BlockDriver *drv = bs->drv; | |
2733 | if (drv && drv->bdrv_flush_io_queue) { | |
2734 | drv->bdrv_flush_io_queue(bs); | |
2735 | } else if (bs->file) { | |
9a4f4c31 | 2736 | bdrv_flush_io_queue(bs->file->bs); |
61007b31 | 2737 | } |
f406c03c | 2738 | bdrv_start_throttled_reqs(bs); |
61007b31 | 2739 | } |
51288d79 FZ |
2740 | |
2741 | void bdrv_drained_begin(BlockDriverState *bs) | |
2742 | { | |
2743 | if (!bs->quiesce_counter++) { | |
2744 | aio_disable_external(bdrv_get_aio_context(bs)); | |
2745 | } | |
2746 | bdrv_drain(bs); | |
2747 | } | |
2748 | ||
2749 | void bdrv_drained_end(BlockDriverState *bs) | |
2750 | { | |
2751 | assert(bs->quiesce_counter > 0); | |
2752 | if (--bs->quiesce_counter > 0) { | |
2753 | return; | |
2754 | } | |
2755 | aio_enable_external(bdrv_get_aio_context(bs)); | |
2756 | } |