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Commit | Line | Data |
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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 | ||
80c71a24 | 25 | #include "qemu/osdep.h" |
61007b31 | 26 | #include "trace.h" |
7f0e9da6 | 27 | #include "sysemu/block-backend.h" |
61007b31 SH |
28 | #include "block/blockjob.h" |
29 | #include "block/block_int.h" | |
76f4afb4 | 30 | #include "block/throttle-groups.h" |
d49b6836 | 31 | #include "qemu/error-report.h" |
61007b31 SH |
32 | |
33 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
34 | ||
35 | static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, | |
36 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
37 | BlockCompletionFunc *cb, void *opaque); | |
38 | static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, | |
39 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
40 | BlockCompletionFunc *cb, void *opaque); | |
41 | static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, | |
42 | int64_t sector_num, int nb_sectors, | |
43 | QEMUIOVector *iov); | |
44 | static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, | |
45 | int64_t sector_num, int nb_sectors, | |
46 | QEMUIOVector *iov); | |
47 | static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, | |
48 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
49 | BdrvRequestFlags flags); | |
50 | static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, | |
51 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
52 | BdrvRequestFlags flags); | |
53 | static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, | |
54 | int64_t sector_num, | |
55 | QEMUIOVector *qiov, | |
56 | int nb_sectors, | |
57 | BdrvRequestFlags flags, | |
58 | BlockCompletionFunc *cb, | |
59 | void *opaque, | |
60 | bool is_write); | |
61 | static void coroutine_fn bdrv_co_do_rw(void *opaque); | |
62 | static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, | |
63 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); | |
64 | ||
65 | /* throttling disk I/O limits */ | |
66 | void bdrv_set_io_limits(BlockDriverState *bs, | |
67 | ThrottleConfig *cfg) | |
68 | { | |
69 | int i; | |
70 | ||
76f4afb4 | 71 | throttle_group_config(bs, cfg); |
61007b31 SH |
72 | |
73 | for (i = 0; i < 2; i++) { | |
74 | qemu_co_enter_next(&bs->throttled_reqs[i]); | |
75 | } | |
76 | } | |
77 | ||
78 | /* this function drain all the throttled IOs */ | |
79 | static bool bdrv_start_throttled_reqs(BlockDriverState *bs) | |
80 | { | |
81 | bool drained = false; | |
82 | bool enabled = bs->io_limits_enabled; | |
83 | int i; | |
84 | ||
85 | bs->io_limits_enabled = false; | |
86 | ||
87 | for (i = 0; i < 2; i++) { | |
88 | while (qemu_co_enter_next(&bs->throttled_reqs[i])) { | |
89 | drained = true; | |
90 | } | |
91 | } | |
92 | ||
93 | bs->io_limits_enabled = enabled; | |
94 | ||
95 | return drained; | |
96 | } | |
97 | ||
98 | void bdrv_io_limits_disable(BlockDriverState *bs) | |
99 | { | |
100 | bs->io_limits_enabled = false; | |
61007b31 | 101 | bdrv_start_throttled_reqs(bs); |
76f4afb4 | 102 | throttle_group_unregister_bs(bs); |
61007b31 SH |
103 | } |
104 | ||
105 | /* should be called before bdrv_set_io_limits if a limit is set */ | |
76f4afb4 | 106 | void bdrv_io_limits_enable(BlockDriverState *bs, const char *group) |
61007b31 | 107 | { |
61007b31 | 108 | assert(!bs->io_limits_enabled); |
76f4afb4 | 109 | throttle_group_register_bs(bs, group); |
61007b31 SH |
110 | bs->io_limits_enabled = true; |
111 | } | |
112 | ||
76f4afb4 | 113 | void bdrv_io_limits_update_group(BlockDriverState *bs, const char *group) |
61007b31 | 114 | { |
76f4afb4 AG |
115 | /* this bs is not part of any group */ |
116 | if (!bs->throttle_state) { | |
117 | return; | |
61007b31 SH |
118 | } |
119 | ||
76f4afb4 AG |
120 | /* this bs is a part of the same group than the one we want */ |
121 | if (!g_strcmp0(throttle_group_get_name(bs), group)) { | |
61007b31 SH |
122 | return; |
123 | } | |
124 | ||
76f4afb4 AG |
125 | /* need to change the group this bs belong to */ |
126 | bdrv_io_limits_disable(bs); | |
127 | bdrv_io_limits_enable(bs, group); | |
61007b31 SH |
128 | } |
129 | ||
130 | void bdrv_setup_io_funcs(BlockDriver *bdrv) | |
131 | { | |
132 | /* Block drivers without coroutine functions need emulation */ | |
133 | if (!bdrv->bdrv_co_readv) { | |
134 | bdrv->bdrv_co_readv = bdrv_co_readv_em; | |
135 | bdrv->bdrv_co_writev = bdrv_co_writev_em; | |
136 | ||
137 | /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if | |
138 | * the block driver lacks aio we need to emulate that too. | |
139 | */ | |
140 | if (!bdrv->bdrv_aio_readv) { | |
141 | /* add AIO emulation layer */ | |
142 | bdrv->bdrv_aio_readv = bdrv_aio_readv_em; | |
143 | bdrv->bdrv_aio_writev = bdrv_aio_writev_em; | |
144 | } | |
145 | } | |
146 | } | |
147 | ||
148 | void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) | |
149 | { | |
150 | BlockDriver *drv = bs->drv; | |
151 | Error *local_err = NULL; | |
152 | ||
153 | memset(&bs->bl, 0, sizeof(bs->bl)); | |
154 | ||
155 | if (!drv) { | |
156 | return; | |
157 | } | |
158 | ||
159 | /* Take some limits from the children as a default */ | |
160 | if (bs->file) { | |
9a4f4c31 | 161 | bdrv_refresh_limits(bs->file->bs, &local_err); |
61007b31 SH |
162 | if (local_err) { |
163 | error_propagate(errp, local_err); | |
164 | return; | |
165 | } | |
9a4f4c31 KW |
166 | bs->bl.opt_transfer_length = bs->file->bs->bl.opt_transfer_length; |
167 | bs->bl.max_transfer_length = bs->file->bs->bl.max_transfer_length; | |
168 | bs->bl.min_mem_alignment = bs->file->bs->bl.min_mem_alignment; | |
169 | bs->bl.opt_mem_alignment = bs->file->bs->bl.opt_mem_alignment; | |
bd44feb7 | 170 | bs->bl.max_iov = bs->file->bs->bl.max_iov; |
61007b31 | 171 | } else { |
4196d2f0 | 172 | bs->bl.min_mem_alignment = 512; |
459b4e66 | 173 | bs->bl.opt_mem_alignment = getpagesize(); |
bd44feb7 SH |
174 | |
175 | /* Safe default since most protocols use readv()/writev()/etc */ | |
176 | bs->bl.max_iov = IOV_MAX; | |
61007b31 SH |
177 | } |
178 | ||
760e0063 KW |
179 | if (bs->backing) { |
180 | bdrv_refresh_limits(bs->backing->bs, &local_err); | |
61007b31 SH |
181 | if (local_err) { |
182 | error_propagate(errp, local_err); | |
183 | return; | |
184 | } | |
185 | bs->bl.opt_transfer_length = | |
186 | MAX(bs->bl.opt_transfer_length, | |
760e0063 | 187 | bs->backing->bs->bl.opt_transfer_length); |
61007b31 SH |
188 | bs->bl.max_transfer_length = |
189 | MIN_NON_ZERO(bs->bl.max_transfer_length, | |
760e0063 | 190 | bs->backing->bs->bl.max_transfer_length); |
61007b31 SH |
191 | bs->bl.opt_mem_alignment = |
192 | MAX(bs->bl.opt_mem_alignment, | |
760e0063 | 193 | bs->backing->bs->bl.opt_mem_alignment); |
4196d2f0 DL |
194 | bs->bl.min_mem_alignment = |
195 | MAX(bs->bl.min_mem_alignment, | |
760e0063 | 196 | bs->backing->bs->bl.min_mem_alignment); |
bd44feb7 SH |
197 | bs->bl.max_iov = |
198 | MIN(bs->bl.max_iov, | |
199 | bs->backing->bs->bl.max_iov); | |
61007b31 SH |
200 | } |
201 | ||
202 | /* Then let the driver override it */ | |
203 | if (drv->bdrv_refresh_limits) { | |
204 | drv->bdrv_refresh_limits(bs, errp); | |
205 | } | |
206 | } | |
207 | ||
208 | /** | |
209 | * The copy-on-read flag is actually a reference count so multiple users may | |
210 | * use the feature without worrying about clobbering its previous state. | |
211 | * Copy-on-read stays enabled until all users have called to disable it. | |
212 | */ | |
213 | void bdrv_enable_copy_on_read(BlockDriverState *bs) | |
214 | { | |
215 | bs->copy_on_read++; | |
216 | } | |
217 | ||
218 | void bdrv_disable_copy_on_read(BlockDriverState *bs) | |
219 | { | |
220 | assert(bs->copy_on_read > 0); | |
221 | bs->copy_on_read--; | |
222 | } | |
223 | ||
224 | /* Check if any requests are in-flight (including throttled requests) */ | |
439db28c | 225 | bool bdrv_requests_pending(BlockDriverState *bs) |
61007b31 | 226 | { |
37a639a7 KW |
227 | BdrvChild *child; |
228 | ||
61007b31 SH |
229 | if (!QLIST_EMPTY(&bs->tracked_requests)) { |
230 | return true; | |
231 | } | |
232 | if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) { | |
233 | return true; | |
234 | } | |
235 | if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) { | |
236 | return true; | |
237 | } | |
37a639a7 KW |
238 | |
239 | QLIST_FOREACH(child, &bs->children, next) { | |
240 | if (bdrv_requests_pending(child->bs)) { | |
241 | return true; | |
242 | } | |
61007b31 | 243 | } |
37a639a7 | 244 | |
61007b31 SH |
245 | return false; |
246 | } | |
247 | ||
67da1dc5 FZ |
248 | static void bdrv_drain_recurse(BlockDriverState *bs) |
249 | { | |
250 | BdrvChild *child; | |
251 | ||
252 | if (bs->drv && bs->drv->bdrv_drain) { | |
253 | bs->drv->bdrv_drain(bs); | |
254 | } | |
255 | QLIST_FOREACH(child, &bs->children, next) { | |
256 | bdrv_drain_recurse(child->bs); | |
257 | } | |
258 | } | |
259 | ||
61007b31 | 260 | /* |
67da1dc5 FZ |
261 | * Wait for pending requests to complete on a single BlockDriverState subtree, |
262 | * and suspend block driver's internal I/O until next request arrives. | |
61007b31 | 263 | * |
61007b31 SH |
264 | * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState |
265 | * AioContext. | |
7a63f3cd SH |
266 | * |
267 | * Only this BlockDriverState's AioContext is run, so in-flight requests must | |
268 | * not depend on events in other AioContexts. In that case, use | |
269 | * bdrv_drain_all() instead. | |
61007b31 SH |
270 | */ |
271 | void bdrv_drain(BlockDriverState *bs) | |
272 | { | |
f406c03c AY |
273 | bool busy = true; |
274 | ||
67da1dc5 | 275 | bdrv_drain_recurse(bs); |
f406c03c | 276 | while (busy) { |
61007b31 | 277 | /* Keep iterating */ |
f406c03c AY |
278 | bdrv_flush_io_queue(bs); |
279 | busy = bdrv_requests_pending(bs); | |
280 | busy |= aio_poll(bdrv_get_aio_context(bs), busy); | |
61007b31 SH |
281 | } |
282 | } | |
283 | ||
284 | /* | |
285 | * Wait for pending requests to complete across all BlockDriverStates | |
286 | * | |
287 | * This function does not flush data to disk, use bdrv_flush_all() for that | |
288 | * after calling this function. | |
61007b31 SH |
289 | */ |
290 | void bdrv_drain_all(void) | |
291 | { | |
292 | /* Always run first iteration so any pending completion BHs run */ | |
293 | bool busy = true; | |
294 | BlockDriverState *bs = NULL; | |
f406c03c | 295 | GSList *aio_ctxs = NULL, *ctx; |
61007b31 SH |
296 | |
297 | while ((bs = bdrv_next(bs))) { | |
298 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
299 | ||
300 | aio_context_acquire(aio_context); | |
301 | if (bs->job) { | |
302 | block_job_pause(bs->job); | |
303 | } | |
9dcf8ecd | 304 | bdrv_drain_recurse(bs); |
61007b31 | 305 | aio_context_release(aio_context); |
f406c03c | 306 | |
764ba3ae | 307 | if (!g_slist_find(aio_ctxs, aio_context)) { |
f406c03c AY |
308 | aio_ctxs = g_slist_prepend(aio_ctxs, aio_context); |
309 | } | |
61007b31 SH |
310 | } |
311 | ||
7a63f3cd SH |
312 | /* Note that completion of an asynchronous I/O operation can trigger any |
313 | * number of other I/O operations on other devices---for example a | |
314 | * coroutine can submit an I/O request to another device in response to | |
315 | * request completion. Therefore we must keep looping until there was no | |
316 | * more activity rather than simply draining each device independently. | |
317 | */ | |
61007b31 SH |
318 | while (busy) { |
319 | busy = false; | |
61007b31 | 320 | |
f406c03c AY |
321 | for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) { |
322 | AioContext *aio_context = ctx->data; | |
323 | bs = NULL; | |
61007b31 SH |
324 | |
325 | aio_context_acquire(aio_context); | |
f406c03c AY |
326 | while ((bs = bdrv_next(bs))) { |
327 | if (aio_context == bdrv_get_aio_context(bs)) { | |
328 | bdrv_flush_io_queue(bs); | |
329 | if (bdrv_requests_pending(bs)) { | |
330 | busy = true; | |
331 | aio_poll(aio_context, busy); | |
332 | } | |
333 | } | |
334 | } | |
335 | busy |= aio_poll(aio_context, false); | |
61007b31 SH |
336 | aio_context_release(aio_context); |
337 | } | |
338 | } | |
339 | ||
340 | bs = NULL; | |
341 | while ((bs = bdrv_next(bs))) { | |
342 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
343 | ||
344 | aio_context_acquire(aio_context); | |
345 | if (bs->job) { | |
346 | block_job_resume(bs->job); | |
347 | } | |
348 | aio_context_release(aio_context); | |
349 | } | |
f406c03c | 350 | g_slist_free(aio_ctxs); |
61007b31 SH |
351 | } |
352 | ||
353 | /** | |
354 | * Remove an active request from the tracked requests list | |
355 | * | |
356 | * This function should be called when a tracked request is completing. | |
357 | */ | |
358 | static void tracked_request_end(BdrvTrackedRequest *req) | |
359 | { | |
360 | if (req->serialising) { | |
361 | req->bs->serialising_in_flight--; | |
362 | } | |
363 | ||
364 | QLIST_REMOVE(req, list); | |
365 | qemu_co_queue_restart_all(&req->wait_queue); | |
366 | } | |
367 | ||
368 | /** | |
369 | * Add an active request to the tracked requests list | |
370 | */ | |
371 | static void tracked_request_begin(BdrvTrackedRequest *req, | |
372 | BlockDriverState *bs, | |
373 | int64_t offset, | |
ebde595c FZ |
374 | unsigned int bytes, |
375 | enum BdrvTrackedRequestType type) | |
61007b31 SH |
376 | { |
377 | *req = (BdrvTrackedRequest){ | |
378 | .bs = bs, | |
379 | .offset = offset, | |
380 | .bytes = bytes, | |
ebde595c | 381 | .type = type, |
61007b31 SH |
382 | .co = qemu_coroutine_self(), |
383 | .serialising = false, | |
384 | .overlap_offset = offset, | |
385 | .overlap_bytes = bytes, | |
386 | }; | |
387 | ||
388 | qemu_co_queue_init(&req->wait_queue); | |
389 | ||
390 | QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); | |
391 | } | |
392 | ||
393 | static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) | |
394 | { | |
395 | int64_t overlap_offset = req->offset & ~(align - 1); | |
396 | unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align) | |
397 | - overlap_offset; | |
398 | ||
399 | if (!req->serialising) { | |
400 | req->bs->serialising_in_flight++; | |
401 | req->serialising = true; | |
402 | } | |
403 | ||
404 | req->overlap_offset = MIN(req->overlap_offset, overlap_offset); | |
405 | req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); | |
406 | } | |
407 | ||
408 | /** | |
409 | * Round a region to cluster boundaries | |
410 | */ | |
411 | void bdrv_round_to_clusters(BlockDriverState *bs, | |
412 | int64_t sector_num, int nb_sectors, | |
413 | int64_t *cluster_sector_num, | |
414 | int *cluster_nb_sectors) | |
415 | { | |
416 | BlockDriverInfo bdi; | |
417 | ||
418 | if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { | |
419 | *cluster_sector_num = sector_num; | |
420 | *cluster_nb_sectors = nb_sectors; | |
421 | } else { | |
422 | int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; | |
423 | *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); | |
424 | *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + | |
425 | nb_sectors, c); | |
426 | } | |
427 | } | |
428 | ||
429 | static int bdrv_get_cluster_size(BlockDriverState *bs) | |
430 | { | |
431 | BlockDriverInfo bdi; | |
432 | int ret; | |
433 | ||
434 | ret = bdrv_get_info(bs, &bdi); | |
435 | if (ret < 0 || bdi.cluster_size == 0) { | |
436 | return bs->request_alignment; | |
437 | } else { | |
438 | return bdi.cluster_size; | |
439 | } | |
440 | } | |
441 | ||
442 | static bool tracked_request_overlaps(BdrvTrackedRequest *req, | |
443 | int64_t offset, unsigned int bytes) | |
444 | { | |
445 | /* aaaa bbbb */ | |
446 | if (offset >= req->overlap_offset + req->overlap_bytes) { | |
447 | return false; | |
448 | } | |
449 | /* bbbb aaaa */ | |
450 | if (req->overlap_offset >= offset + bytes) { | |
451 | return false; | |
452 | } | |
453 | return true; | |
454 | } | |
455 | ||
456 | static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) | |
457 | { | |
458 | BlockDriverState *bs = self->bs; | |
459 | BdrvTrackedRequest *req; | |
460 | bool retry; | |
461 | bool waited = false; | |
462 | ||
463 | if (!bs->serialising_in_flight) { | |
464 | return false; | |
465 | } | |
466 | ||
467 | do { | |
468 | retry = false; | |
469 | QLIST_FOREACH(req, &bs->tracked_requests, list) { | |
470 | if (req == self || (!req->serialising && !self->serialising)) { | |
471 | continue; | |
472 | } | |
473 | if (tracked_request_overlaps(req, self->overlap_offset, | |
474 | self->overlap_bytes)) | |
475 | { | |
476 | /* Hitting this means there was a reentrant request, for | |
477 | * example, a block driver issuing nested requests. This must | |
478 | * never happen since it means deadlock. | |
479 | */ | |
480 | assert(qemu_coroutine_self() != req->co); | |
481 | ||
482 | /* If the request is already (indirectly) waiting for us, or | |
483 | * will wait for us as soon as it wakes up, then just go on | |
484 | * (instead of producing a deadlock in the former case). */ | |
485 | if (!req->waiting_for) { | |
486 | self->waiting_for = req; | |
487 | qemu_co_queue_wait(&req->wait_queue); | |
488 | self->waiting_for = NULL; | |
489 | retry = true; | |
490 | waited = true; | |
491 | break; | |
492 | } | |
493 | } | |
494 | } | |
495 | } while (retry); | |
496 | ||
497 | return waited; | |
498 | } | |
499 | ||
500 | static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, | |
501 | size_t size) | |
502 | { | |
503 | if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) { | |
504 | return -EIO; | |
505 | } | |
506 | ||
507 | if (!bdrv_is_inserted(bs)) { | |
508 | return -ENOMEDIUM; | |
509 | } | |
510 | ||
511 | if (offset < 0) { | |
512 | return -EIO; | |
513 | } | |
514 | ||
515 | return 0; | |
516 | } | |
517 | ||
518 | static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, | |
519 | int nb_sectors) | |
520 | { | |
521 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
522 | return -EIO; | |
523 | } | |
524 | ||
525 | return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE, | |
526 | nb_sectors * BDRV_SECTOR_SIZE); | |
527 | } | |
528 | ||
529 | typedef struct RwCo { | |
530 | BlockDriverState *bs; | |
531 | int64_t offset; | |
532 | QEMUIOVector *qiov; | |
533 | bool is_write; | |
534 | int ret; | |
535 | BdrvRequestFlags flags; | |
536 | } RwCo; | |
537 | ||
538 | static void coroutine_fn bdrv_rw_co_entry(void *opaque) | |
539 | { | |
540 | RwCo *rwco = opaque; | |
541 | ||
542 | if (!rwco->is_write) { | |
543 | rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset, | |
544 | rwco->qiov->size, rwco->qiov, | |
545 | rwco->flags); | |
546 | } else { | |
547 | rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset, | |
548 | rwco->qiov->size, rwco->qiov, | |
549 | rwco->flags); | |
550 | } | |
551 | } | |
552 | ||
553 | /* | |
554 | * Process a vectored synchronous request using coroutines | |
555 | */ | |
556 | static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset, | |
557 | QEMUIOVector *qiov, bool is_write, | |
558 | BdrvRequestFlags flags) | |
559 | { | |
560 | Coroutine *co; | |
561 | RwCo rwco = { | |
562 | .bs = bs, | |
563 | .offset = offset, | |
564 | .qiov = qiov, | |
565 | .is_write = is_write, | |
566 | .ret = NOT_DONE, | |
567 | .flags = flags, | |
568 | }; | |
569 | ||
570 | /** | |
571 | * In sync call context, when the vcpu is blocked, this throttling timer | |
572 | * will not fire; so the I/O throttling function has to be disabled here | |
573 | * if it has been enabled. | |
574 | */ | |
575 | if (bs->io_limits_enabled) { | |
576 | fprintf(stderr, "Disabling I/O throttling on '%s' due " | |
577 | "to synchronous I/O.\n", bdrv_get_device_name(bs)); | |
578 | bdrv_io_limits_disable(bs); | |
579 | } | |
580 | ||
581 | if (qemu_in_coroutine()) { | |
582 | /* Fast-path if already in coroutine context */ | |
583 | bdrv_rw_co_entry(&rwco); | |
584 | } else { | |
585 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
586 | ||
587 | co = qemu_coroutine_create(bdrv_rw_co_entry); | |
588 | qemu_coroutine_enter(co, &rwco); | |
589 | while (rwco.ret == NOT_DONE) { | |
590 | aio_poll(aio_context, true); | |
591 | } | |
592 | } | |
593 | return rwco.ret; | |
594 | } | |
595 | ||
596 | /* | |
597 | * Process a synchronous request using coroutines | |
598 | */ | |
599 | static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, | |
600 | int nb_sectors, bool is_write, BdrvRequestFlags flags) | |
601 | { | |
602 | QEMUIOVector qiov; | |
603 | struct iovec iov = { | |
604 | .iov_base = (void *)buf, | |
605 | .iov_len = nb_sectors * BDRV_SECTOR_SIZE, | |
606 | }; | |
607 | ||
608 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
609 | return -EINVAL; | |
610 | } | |
611 | ||
612 | qemu_iovec_init_external(&qiov, &iov, 1); | |
613 | return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS, | |
614 | &qiov, is_write, flags); | |
615 | } | |
616 | ||
617 | /* return < 0 if error. See bdrv_write() for the return codes */ | |
618 | int bdrv_read(BlockDriverState *bs, int64_t sector_num, | |
619 | uint8_t *buf, int nb_sectors) | |
620 | { | |
621 | return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0); | |
622 | } | |
623 | ||
624 | /* Just like bdrv_read(), but with I/O throttling temporarily disabled */ | |
625 | int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num, | |
626 | uint8_t *buf, int nb_sectors) | |
627 | { | |
628 | bool enabled; | |
629 | int ret; | |
630 | ||
631 | enabled = bs->io_limits_enabled; | |
632 | bs->io_limits_enabled = false; | |
633 | ret = bdrv_read(bs, sector_num, buf, nb_sectors); | |
634 | bs->io_limits_enabled = enabled; | |
635 | return ret; | |
636 | } | |
637 | ||
638 | /* Return < 0 if error. Important errors are: | |
639 | -EIO generic I/O error (may happen for all errors) | |
640 | -ENOMEDIUM No media inserted. | |
641 | -EINVAL Invalid sector number or nb_sectors | |
642 | -EACCES Trying to write a read-only device | |
643 | */ | |
644 | int bdrv_write(BlockDriverState *bs, int64_t sector_num, | |
645 | const uint8_t *buf, int nb_sectors) | |
646 | { | |
647 | return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0); | |
648 | } | |
649 | ||
650 | int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, | |
651 | int nb_sectors, BdrvRequestFlags flags) | |
652 | { | |
653 | return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true, | |
654 | BDRV_REQ_ZERO_WRITE | flags); | |
655 | } | |
656 | ||
657 | /* | |
658 | * Completely zero out a block device with the help of bdrv_write_zeroes. | |
659 | * The operation is sped up by checking the block status and only writing | |
660 | * zeroes to the device if they currently do not return zeroes. Optional | |
661 | * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP). | |
662 | * | |
663 | * Returns < 0 on error, 0 on success. For error codes see bdrv_write(). | |
664 | */ | |
665 | int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags) | |
666 | { | |
667 | int64_t target_sectors, ret, nb_sectors, sector_num = 0; | |
67a0fd2a | 668 | BlockDriverState *file; |
61007b31 SH |
669 | int n; |
670 | ||
671 | target_sectors = bdrv_nb_sectors(bs); | |
672 | if (target_sectors < 0) { | |
673 | return target_sectors; | |
674 | } | |
675 | ||
676 | for (;;) { | |
677 | nb_sectors = MIN(target_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS); | |
678 | if (nb_sectors <= 0) { | |
679 | return 0; | |
680 | } | |
67a0fd2a | 681 | ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n, &file); |
61007b31 SH |
682 | if (ret < 0) { |
683 | error_report("error getting block status at sector %" PRId64 ": %s", | |
684 | sector_num, strerror(-ret)); | |
685 | return ret; | |
686 | } | |
687 | if (ret & BDRV_BLOCK_ZERO) { | |
688 | sector_num += n; | |
689 | continue; | |
690 | } | |
691 | ret = bdrv_write_zeroes(bs, sector_num, n, flags); | |
692 | if (ret < 0) { | |
693 | error_report("error writing zeroes at sector %" PRId64 ": %s", | |
694 | sector_num, strerror(-ret)); | |
695 | return ret; | |
696 | } | |
697 | sector_num += n; | |
698 | } | |
699 | } | |
700 | ||
701 | int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes) | |
702 | { | |
703 | QEMUIOVector qiov; | |
704 | struct iovec iov = { | |
705 | .iov_base = (void *)buf, | |
706 | .iov_len = bytes, | |
707 | }; | |
708 | int ret; | |
709 | ||
710 | if (bytes < 0) { | |
711 | return -EINVAL; | |
712 | } | |
713 | ||
714 | qemu_iovec_init_external(&qiov, &iov, 1); | |
715 | ret = bdrv_prwv_co(bs, offset, &qiov, false, 0); | |
716 | if (ret < 0) { | |
717 | return ret; | |
718 | } | |
719 | ||
720 | return bytes; | |
721 | } | |
722 | ||
723 | int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) | |
724 | { | |
725 | int ret; | |
726 | ||
727 | ret = bdrv_prwv_co(bs, offset, qiov, true, 0); | |
728 | if (ret < 0) { | |
729 | return ret; | |
730 | } | |
731 | ||
732 | return qiov->size; | |
733 | } | |
734 | ||
735 | int bdrv_pwrite(BlockDriverState *bs, int64_t offset, | |
736 | const void *buf, int bytes) | |
737 | { | |
738 | QEMUIOVector qiov; | |
739 | struct iovec iov = { | |
740 | .iov_base = (void *) buf, | |
741 | .iov_len = bytes, | |
742 | }; | |
743 | ||
744 | if (bytes < 0) { | |
745 | return -EINVAL; | |
746 | } | |
747 | ||
748 | qemu_iovec_init_external(&qiov, &iov, 1); | |
749 | return bdrv_pwritev(bs, offset, &qiov); | |
750 | } | |
751 | ||
752 | /* | |
753 | * Writes to the file and ensures that no writes are reordered across this | |
754 | * request (acts as a barrier) | |
755 | * | |
756 | * Returns 0 on success, -errno in error cases. | |
757 | */ | |
758 | int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, | |
759 | const void *buf, int count) | |
760 | { | |
761 | int ret; | |
762 | ||
763 | ret = bdrv_pwrite(bs, offset, buf, count); | |
764 | if (ret < 0) { | |
765 | return ret; | |
766 | } | |
767 | ||
768 | /* No flush needed for cache modes that already do it */ | |
769 | if (bs->enable_write_cache) { | |
770 | bdrv_flush(bs); | |
771 | } | |
772 | ||
773 | return 0; | |
774 | } | |
775 | ||
776 | static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, | |
777 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) | |
778 | { | |
779 | /* Perform I/O through a temporary buffer so that users who scribble over | |
780 | * their read buffer while the operation is in progress do not end up | |
781 | * modifying the image file. This is critical for zero-copy guest I/O | |
782 | * where anything might happen inside guest memory. | |
783 | */ | |
784 | void *bounce_buffer; | |
785 | ||
786 | BlockDriver *drv = bs->drv; | |
787 | struct iovec iov; | |
788 | QEMUIOVector bounce_qiov; | |
789 | int64_t cluster_sector_num; | |
790 | int cluster_nb_sectors; | |
791 | size_t skip_bytes; | |
792 | int ret; | |
793 | ||
794 | /* Cover entire cluster so no additional backing file I/O is required when | |
795 | * allocating cluster in the image file. | |
796 | */ | |
797 | bdrv_round_to_clusters(bs, sector_num, nb_sectors, | |
798 | &cluster_sector_num, &cluster_nb_sectors); | |
799 | ||
800 | trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, | |
801 | cluster_sector_num, cluster_nb_sectors); | |
802 | ||
803 | iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; | |
804 | iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len); | |
805 | if (bounce_buffer == NULL) { | |
806 | ret = -ENOMEM; | |
807 | goto err; | |
808 | } | |
809 | ||
810 | qemu_iovec_init_external(&bounce_qiov, &iov, 1); | |
811 | ||
812 | ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, | |
813 | &bounce_qiov); | |
814 | if (ret < 0) { | |
815 | goto err; | |
816 | } | |
817 | ||
818 | if (drv->bdrv_co_write_zeroes && | |
819 | buffer_is_zero(bounce_buffer, iov.iov_len)) { | |
820 | ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, | |
821 | cluster_nb_sectors, 0); | |
822 | } else { | |
823 | /* This does not change the data on the disk, it is not necessary | |
824 | * to flush even in cache=writethrough mode. | |
825 | */ | |
826 | ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, | |
827 | &bounce_qiov); | |
828 | } | |
829 | ||
830 | if (ret < 0) { | |
831 | /* It might be okay to ignore write errors for guest requests. If this | |
832 | * is a deliberate copy-on-read then we don't want to ignore the error. | |
833 | * Simply report it in all cases. | |
834 | */ | |
835 | goto err; | |
836 | } | |
837 | ||
838 | skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; | |
839 | qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, | |
840 | nb_sectors * BDRV_SECTOR_SIZE); | |
841 | ||
842 | err: | |
843 | qemu_vfree(bounce_buffer); | |
844 | return ret; | |
845 | } | |
846 | ||
847 | /* | |
848 | * Forwards an already correctly aligned request to the BlockDriver. This | |
849 | * handles copy on read and zeroing after EOF; any other features must be | |
850 | * implemented by the caller. | |
851 | */ | |
852 | static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, | |
853 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, | |
854 | int64_t align, QEMUIOVector *qiov, int flags) | |
855 | { | |
856 | BlockDriver *drv = bs->drv; | |
857 | int ret; | |
858 | ||
859 | int64_t sector_num = offset >> BDRV_SECTOR_BITS; | |
860 | unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
861 | ||
862 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
863 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
864 | assert(!qiov || bytes == qiov->size); | |
865 | ||
866 | /* Handle Copy on Read and associated serialisation */ | |
867 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
868 | /* If we touch the same cluster it counts as an overlap. This | |
869 | * guarantees that allocating writes will be serialized and not race | |
870 | * with each other for the same cluster. For example, in copy-on-read | |
871 | * it ensures that the CoR read and write operations are atomic and | |
872 | * guest writes cannot interleave between them. */ | |
873 | mark_request_serialising(req, bdrv_get_cluster_size(bs)); | |
874 | } | |
875 | ||
61408b25 FZ |
876 | if (!(flags & BDRV_REQ_NO_SERIALISING)) { |
877 | wait_serialising_requests(req); | |
878 | } | |
61007b31 SH |
879 | |
880 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
881 | int pnum; | |
882 | ||
883 | ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum); | |
884 | if (ret < 0) { | |
885 | goto out; | |
886 | } | |
887 | ||
888 | if (!ret || pnum != nb_sectors) { | |
889 | ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); | |
890 | goto out; | |
891 | } | |
892 | } | |
893 | ||
894 | /* Forward the request to the BlockDriver */ | |
895 | if (!bs->zero_beyond_eof) { | |
896 | ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); | |
897 | } else { | |
898 | /* Read zeros after EOF */ | |
899 | int64_t total_sectors, max_nb_sectors; | |
900 | ||
901 | total_sectors = bdrv_nb_sectors(bs); | |
902 | if (total_sectors < 0) { | |
903 | ret = total_sectors; | |
904 | goto out; | |
905 | } | |
906 | ||
907 | max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num), | |
908 | align >> BDRV_SECTOR_BITS); | |
909 | if (nb_sectors < max_nb_sectors) { | |
910 | ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); | |
911 | } else if (max_nb_sectors > 0) { | |
912 | QEMUIOVector local_qiov; | |
913 | ||
914 | qemu_iovec_init(&local_qiov, qiov->niov); | |
915 | qemu_iovec_concat(&local_qiov, qiov, 0, | |
916 | max_nb_sectors * BDRV_SECTOR_SIZE); | |
917 | ||
918 | ret = drv->bdrv_co_readv(bs, sector_num, max_nb_sectors, | |
919 | &local_qiov); | |
920 | ||
921 | qemu_iovec_destroy(&local_qiov); | |
922 | } else { | |
923 | ret = 0; | |
924 | } | |
925 | ||
926 | /* Reading beyond end of file is supposed to produce zeroes */ | |
927 | if (ret == 0 && total_sectors < sector_num + nb_sectors) { | |
928 | uint64_t offset = MAX(0, total_sectors - sector_num); | |
929 | uint64_t bytes = (sector_num + nb_sectors - offset) * | |
930 | BDRV_SECTOR_SIZE; | |
931 | qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes); | |
932 | } | |
933 | } | |
934 | ||
935 | out: | |
936 | return ret; | |
937 | } | |
938 | ||
61007b31 SH |
939 | /* |
940 | * Handle a read request in coroutine context | |
941 | */ | |
942 | static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, | |
943 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
944 | BdrvRequestFlags flags) | |
945 | { | |
946 | BlockDriver *drv = bs->drv; | |
947 | BdrvTrackedRequest req; | |
948 | ||
d01c07f2 FZ |
949 | /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ |
950 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
61007b31 SH |
951 | uint8_t *head_buf = NULL; |
952 | uint8_t *tail_buf = NULL; | |
953 | QEMUIOVector local_qiov; | |
954 | bool use_local_qiov = false; | |
955 | int ret; | |
956 | ||
957 | if (!drv) { | |
958 | return -ENOMEDIUM; | |
959 | } | |
960 | ||
961 | ret = bdrv_check_byte_request(bs, offset, bytes); | |
962 | if (ret < 0) { | |
963 | return ret; | |
964 | } | |
965 | ||
9568b511 | 966 | /* Don't do copy-on-read if we read data before write operation */ |
61408b25 | 967 | if (bs->copy_on_read && !(flags & BDRV_REQ_NO_SERIALISING)) { |
61007b31 SH |
968 | flags |= BDRV_REQ_COPY_ON_READ; |
969 | } | |
970 | ||
971 | /* throttling disk I/O */ | |
972 | if (bs->io_limits_enabled) { | |
76f4afb4 | 973 | throttle_group_co_io_limits_intercept(bs, bytes, false); |
61007b31 SH |
974 | } |
975 | ||
976 | /* Align read if necessary by padding qiov */ | |
977 | if (offset & (align - 1)) { | |
978 | head_buf = qemu_blockalign(bs, align); | |
979 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
980 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
981 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
982 | use_local_qiov = true; | |
983 | ||
984 | bytes += offset & (align - 1); | |
985 | offset = offset & ~(align - 1); | |
986 | } | |
987 | ||
988 | if ((offset + bytes) & (align - 1)) { | |
989 | if (!use_local_qiov) { | |
990 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
991 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
992 | use_local_qiov = true; | |
993 | } | |
994 | tail_buf = qemu_blockalign(bs, align); | |
995 | qemu_iovec_add(&local_qiov, tail_buf, | |
996 | align - ((offset + bytes) & (align - 1))); | |
997 | ||
998 | bytes = ROUND_UP(bytes, align); | |
999 | } | |
1000 | ||
ebde595c | 1001 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ); |
61007b31 SH |
1002 | ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align, |
1003 | use_local_qiov ? &local_qiov : qiov, | |
1004 | flags); | |
1005 | tracked_request_end(&req); | |
1006 | ||
1007 | if (use_local_qiov) { | |
1008 | qemu_iovec_destroy(&local_qiov); | |
1009 | qemu_vfree(head_buf); | |
1010 | qemu_vfree(tail_buf); | |
1011 | } | |
1012 | ||
1013 | return ret; | |
1014 | } | |
1015 | ||
1016 | static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, | |
1017 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, | |
1018 | BdrvRequestFlags flags) | |
1019 | { | |
1020 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
1021 | return -EINVAL; | |
1022 | } | |
1023 | ||
1024 | return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS, | |
1025 | nb_sectors << BDRV_SECTOR_BITS, qiov, flags); | |
1026 | } | |
1027 | ||
1028 | int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, | |
1029 | int nb_sectors, QEMUIOVector *qiov) | |
1030 | { | |
1031 | trace_bdrv_co_readv(bs, sector_num, nb_sectors); | |
1032 | ||
1033 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); | |
1034 | } | |
1035 | ||
61408b25 | 1036 | int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs, |
9568b511 WC |
1037 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) |
1038 | { | |
61408b25 | 1039 | trace_bdrv_co_readv_no_serialising(bs, sector_num, nb_sectors); |
9568b511 WC |
1040 | |
1041 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, | |
61408b25 | 1042 | BDRV_REQ_NO_SERIALISING); |
9568b511 WC |
1043 | } |
1044 | ||
61007b31 SH |
1045 | int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, |
1046 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) | |
1047 | { | |
1048 | trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); | |
1049 | ||
1050 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, | |
1051 | BDRV_REQ_COPY_ON_READ); | |
1052 | } | |
1053 | ||
1054 | #define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768 | |
1055 | ||
1056 | static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, | |
1057 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) | |
1058 | { | |
1059 | BlockDriver *drv = bs->drv; | |
1060 | QEMUIOVector qiov; | |
1061 | struct iovec iov = {0}; | |
1062 | int ret = 0; | |
1063 | ||
1064 | int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes, | |
1065 | BDRV_REQUEST_MAX_SECTORS); | |
1066 | ||
1067 | while (nb_sectors > 0 && !ret) { | |
1068 | int num = nb_sectors; | |
1069 | ||
1070 | /* Align request. Block drivers can expect the "bulk" of the request | |
1071 | * to be aligned. | |
1072 | */ | |
1073 | if (bs->bl.write_zeroes_alignment | |
1074 | && num > bs->bl.write_zeroes_alignment) { | |
1075 | if (sector_num % bs->bl.write_zeroes_alignment != 0) { | |
1076 | /* Make a small request up to the first aligned sector. */ | |
1077 | num = bs->bl.write_zeroes_alignment; | |
1078 | num -= sector_num % bs->bl.write_zeroes_alignment; | |
1079 | } else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) { | |
1080 | /* Shorten the request to the last aligned sector. num cannot | |
1081 | * underflow because num > bs->bl.write_zeroes_alignment. | |
1082 | */ | |
1083 | num -= (sector_num + num) % bs->bl.write_zeroes_alignment; | |
1084 | } | |
1085 | } | |
1086 | ||
1087 | /* limit request size */ | |
1088 | if (num > max_write_zeroes) { | |
1089 | num = max_write_zeroes; | |
1090 | } | |
1091 | ||
1092 | ret = -ENOTSUP; | |
1093 | /* First try the efficient write zeroes operation */ | |
1094 | if (drv->bdrv_co_write_zeroes) { | |
1095 | ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags); | |
1096 | } | |
1097 | ||
1098 | if (ret == -ENOTSUP) { | |
1099 | /* Fall back to bounce buffer if write zeroes is unsupported */ | |
1100 | int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length, | |
1101 | MAX_WRITE_ZEROES_BOUNCE_BUFFER); | |
1102 | num = MIN(num, max_xfer_len); | |
1103 | iov.iov_len = num * BDRV_SECTOR_SIZE; | |
1104 | if (iov.iov_base == NULL) { | |
1105 | iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE); | |
1106 | if (iov.iov_base == NULL) { | |
1107 | ret = -ENOMEM; | |
1108 | goto fail; | |
1109 | } | |
1110 | memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE); | |
1111 | } | |
1112 | qemu_iovec_init_external(&qiov, &iov, 1); | |
1113 | ||
1114 | ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov); | |
1115 | ||
1116 | /* Keep bounce buffer around if it is big enough for all | |
1117 | * all future requests. | |
1118 | */ | |
1119 | if (num < max_xfer_len) { | |
1120 | qemu_vfree(iov.iov_base); | |
1121 | iov.iov_base = NULL; | |
1122 | } | |
1123 | } | |
1124 | ||
1125 | sector_num += num; | |
1126 | nb_sectors -= num; | |
1127 | } | |
1128 | ||
1129 | fail: | |
1130 | qemu_vfree(iov.iov_base); | |
1131 | return ret; | |
1132 | } | |
1133 | ||
1134 | /* | |
1135 | * Forwards an already correctly aligned write request to the BlockDriver. | |
1136 | */ | |
1137 | static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, | |
1138 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, | |
1139 | QEMUIOVector *qiov, int flags) | |
1140 | { | |
1141 | BlockDriver *drv = bs->drv; | |
1142 | bool waited; | |
1143 | int ret; | |
1144 | ||
1145 | int64_t sector_num = offset >> BDRV_SECTOR_BITS; | |
1146 | unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
1147 | ||
1148 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1149 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1150 | assert(!qiov || bytes == qiov->size); | |
1151 | ||
1152 | waited = wait_serialising_requests(req); | |
1153 | assert(!waited || !req->serialising); | |
1154 | assert(req->overlap_offset <= offset); | |
1155 | assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); | |
1156 | ||
1157 | ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); | |
1158 | ||
1159 | if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF && | |
1160 | !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes && | |
1161 | qemu_iovec_is_zero(qiov)) { | |
1162 | flags |= BDRV_REQ_ZERO_WRITE; | |
1163 | if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) { | |
1164 | flags |= BDRV_REQ_MAY_UNMAP; | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | if (ret < 0) { | |
1169 | /* Do nothing, write notifier decided to fail this request */ | |
1170 | } else if (flags & BDRV_REQ_ZERO_WRITE) { | |
9a4f4c31 | 1171 | bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO); |
61007b31 SH |
1172 | ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags); |
1173 | } else { | |
9a4f4c31 | 1174 | bdrv_debug_event(bs, BLKDBG_PWRITEV); |
61007b31 SH |
1175 | ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); |
1176 | } | |
9a4f4c31 | 1177 | bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE); |
61007b31 SH |
1178 | |
1179 | if (ret == 0 && !bs->enable_write_cache) { | |
1180 | ret = bdrv_co_flush(bs); | |
1181 | } | |
1182 | ||
1183 | bdrv_set_dirty(bs, sector_num, nb_sectors); | |
1184 | ||
53d8f9d8 HR |
1185 | if (bs->wr_highest_offset < offset + bytes) { |
1186 | bs->wr_highest_offset = offset + bytes; | |
1187 | } | |
61007b31 SH |
1188 | |
1189 | if (ret >= 0) { | |
1190 | bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); | |
1191 | } | |
1192 | ||
1193 | return ret; | |
1194 | } | |
1195 | ||
9eeb6dd1 FZ |
1196 | static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, |
1197 | int64_t offset, | |
1198 | unsigned int bytes, | |
1199 | BdrvRequestFlags flags, | |
1200 | BdrvTrackedRequest *req) | |
1201 | { | |
1202 | uint8_t *buf = NULL; | |
1203 | QEMUIOVector local_qiov; | |
1204 | struct iovec iov; | |
1205 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
1206 | unsigned int head_padding_bytes, tail_padding_bytes; | |
1207 | int ret = 0; | |
1208 | ||
1209 | head_padding_bytes = offset & (align - 1); | |
1210 | tail_padding_bytes = align - ((offset + bytes) & (align - 1)); | |
1211 | ||
1212 | ||
1213 | assert(flags & BDRV_REQ_ZERO_WRITE); | |
1214 | if (head_padding_bytes || tail_padding_bytes) { | |
1215 | buf = qemu_blockalign(bs, align); | |
1216 | iov = (struct iovec) { | |
1217 | .iov_base = buf, | |
1218 | .iov_len = align, | |
1219 | }; | |
1220 | qemu_iovec_init_external(&local_qiov, &iov, 1); | |
1221 | } | |
1222 | if (head_padding_bytes) { | |
1223 | uint64_t zero_bytes = MIN(bytes, align - head_padding_bytes); | |
1224 | ||
1225 | /* RMW the unaligned part before head. */ | |
1226 | mark_request_serialising(req, align); | |
1227 | wait_serialising_requests(req); | |
9a4f4c31 | 1228 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); |
9eeb6dd1 FZ |
1229 | ret = bdrv_aligned_preadv(bs, req, offset & ~(align - 1), align, |
1230 | align, &local_qiov, 0); | |
1231 | if (ret < 0) { | |
1232 | goto fail; | |
1233 | } | |
9a4f4c31 | 1234 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); |
9eeb6dd1 FZ |
1235 | |
1236 | memset(buf + head_padding_bytes, 0, zero_bytes); | |
1237 | ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align, | |
1238 | &local_qiov, | |
1239 | flags & ~BDRV_REQ_ZERO_WRITE); | |
1240 | if (ret < 0) { | |
1241 | goto fail; | |
1242 | } | |
1243 | offset += zero_bytes; | |
1244 | bytes -= zero_bytes; | |
1245 | } | |
1246 | ||
1247 | assert(!bytes || (offset & (align - 1)) == 0); | |
1248 | if (bytes >= align) { | |
1249 | /* Write the aligned part in the middle. */ | |
1250 | uint64_t aligned_bytes = bytes & ~(align - 1); | |
1251 | ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes, | |
1252 | NULL, flags); | |
1253 | if (ret < 0) { | |
1254 | goto fail; | |
1255 | } | |
1256 | bytes -= aligned_bytes; | |
1257 | offset += aligned_bytes; | |
1258 | } | |
1259 | ||
1260 | assert(!bytes || (offset & (align - 1)) == 0); | |
1261 | if (bytes) { | |
1262 | assert(align == tail_padding_bytes + bytes); | |
1263 | /* RMW the unaligned part after tail. */ | |
1264 | mark_request_serialising(req, align); | |
1265 | wait_serialising_requests(req); | |
9a4f4c31 | 1266 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); |
9eeb6dd1 FZ |
1267 | ret = bdrv_aligned_preadv(bs, req, offset, align, |
1268 | align, &local_qiov, 0); | |
1269 | if (ret < 0) { | |
1270 | goto fail; | |
1271 | } | |
9a4f4c31 | 1272 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); |
9eeb6dd1 FZ |
1273 | |
1274 | memset(buf, 0, bytes); | |
1275 | ret = bdrv_aligned_pwritev(bs, req, offset, align, | |
1276 | &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE); | |
1277 | } | |
1278 | fail: | |
1279 | qemu_vfree(buf); | |
1280 | return ret; | |
1281 | ||
1282 | } | |
1283 | ||
61007b31 SH |
1284 | /* |
1285 | * Handle a write request in coroutine context | |
1286 | */ | |
1287 | static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, | |
1288 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
1289 | BdrvRequestFlags flags) | |
1290 | { | |
1291 | BdrvTrackedRequest req; | |
d01c07f2 FZ |
1292 | /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ |
1293 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
61007b31 SH |
1294 | uint8_t *head_buf = NULL; |
1295 | uint8_t *tail_buf = NULL; | |
1296 | QEMUIOVector local_qiov; | |
1297 | bool use_local_qiov = false; | |
1298 | int ret; | |
1299 | ||
1300 | if (!bs->drv) { | |
1301 | return -ENOMEDIUM; | |
1302 | } | |
1303 | if (bs->read_only) { | |
eaf5fe2d | 1304 | return -EPERM; |
61007b31 | 1305 | } |
04c01a5c | 1306 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); |
61007b31 SH |
1307 | |
1308 | ret = bdrv_check_byte_request(bs, offset, bytes); | |
1309 | if (ret < 0) { | |
1310 | return ret; | |
1311 | } | |
1312 | ||
1313 | /* throttling disk I/O */ | |
1314 | if (bs->io_limits_enabled) { | |
76f4afb4 | 1315 | throttle_group_co_io_limits_intercept(bs, bytes, true); |
61007b31 SH |
1316 | } |
1317 | ||
1318 | /* | |
1319 | * Align write if necessary by performing a read-modify-write cycle. | |
1320 | * Pad qiov with the read parts and be sure to have a tracked request not | |
1321 | * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle. | |
1322 | */ | |
ebde595c | 1323 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE); |
61007b31 | 1324 | |
9eeb6dd1 FZ |
1325 | if (!qiov) { |
1326 | ret = bdrv_co_do_zero_pwritev(bs, offset, bytes, flags, &req); | |
1327 | goto out; | |
1328 | } | |
1329 | ||
61007b31 SH |
1330 | if (offset & (align - 1)) { |
1331 | QEMUIOVector head_qiov; | |
1332 | struct iovec head_iov; | |
1333 | ||
1334 | mark_request_serialising(&req, align); | |
1335 | wait_serialising_requests(&req); | |
1336 | ||
1337 | head_buf = qemu_blockalign(bs, align); | |
1338 | head_iov = (struct iovec) { | |
1339 | .iov_base = head_buf, | |
1340 | .iov_len = align, | |
1341 | }; | |
1342 | qemu_iovec_init_external(&head_qiov, &head_iov, 1); | |
1343 | ||
9a4f4c31 | 1344 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); |
61007b31 SH |
1345 | ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align, |
1346 | align, &head_qiov, 0); | |
1347 | if (ret < 0) { | |
1348 | goto fail; | |
1349 | } | |
9a4f4c31 | 1350 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); |
61007b31 SH |
1351 | |
1352 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
1353 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
1354 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1355 | use_local_qiov = true; | |
1356 | ||
1357 | bytes += offset & (align - 1); | |
1358 | offset = offset & ~(align - 1); | |
1359 | } | |
1360 | ||
1361 | if ((offset + bytes) & (align - 1)) { | |
1362 | QEMUIOVector tail_qiov; | |
1363 | struct iovec tail_iov; | |
1364 | size_t tail_bytes; | |
1365 | bool waited; | |
1366 | ||
1367 | mark_request_serialising(&req, align); | |
1368 | waited = wait_serialising_requests(&req); | |
1369 | assert(!waited || !use_local_qiov); | |
1370 | ||
1371 | tail_buf = qemu_blockalign(bs, align); | |
1372 | tail_iov = (struct iovec) { | |
1373 | .iov_base = tail_buf, | |
1374 | .iov_len = align, | |
1375 | }; | |
1376 | qemu_iovec_init_external(&tail_qiov, &tail_iov, 1); | |
1377 | ||
9a4f4c31 | 1378 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); |
61007b31 SH |
1379 | ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align, |
1380 | align, &tail_qiov, 0); | |
1381 | if (ret < 0) { | |
1382 | goto fail; | |
1383 | } | |
9a4f4c31 | 1384 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); |
61007b31 SH |
1385 | |
1386 | if (!use_local_qiov) { | |
1387 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
1388 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1389 | use_local_qiov = true; | |
1390 | } | |
1391 | ||
1392 | tail_bytes = (offset + bytes) & (align - 1); | |
1393 | qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes); | |
1394 | ||
1395 | bytes = ROUND_UP(bytes, align); | |
1396 | } | |
1397 | ||
61007b31 SH |
1398 | ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, |
1399 | use_local_qiov ? &local_qiov : qiov, | |
1400 | flags); | |
1401 | ||
1402 | fail: | |
61007b31 SH |
1403 | |
1404 | if (use_local_qiov) { | |
1405 | qemu_iovec_destroy(&local_qiov); | |
1406 | } | |
1407 | qemu_vfree(head_buf); | |
1408 | qemu_vfree(tail_buf); | |
9eeb6dd1 FZ |
1409 | out: |
1410 | tracked_request_end(&req); | |
61007b31 SH |
1411 | return ret; |
1412 | } | |
1413 | ||
1414 | static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, | |
1415 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, | |
1416 | BdrvRequestFlags flags) | |
1417 | { | |
1418 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
1419 | return -EINVAL; | |
1420 | } | |
1421 | ||
1422 | return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS, | |
1423 | nb_sectors << BDRV_SECTOR_BITS, qiov, flags); | |
1424 | } | |
1425 | ||
1426 | int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, | |
1427 | int nb_sectors, QEMUIOVector *qiov) | |
1428 | { | |
1429 | trace_bdrv_co_writev(bs, sector_num, nb_sectors); | |
1430 | ||
1431 | return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); | |
1432 | } | |
1433 | ||
1434 | int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, | |
1435 | int64_t sector_num, int nb_sectors, | |
1436 | BdrvRequestFlags flags) | |
1437 | { | |
61007b31 SH |
1438 | trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags); |
1439 | ||
1440 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
1441 | flags &= ~BDRV_REQ_MAY_UNMAP; | |
1442 | } | |
61007b31 | 1443 | |
d01c07f2 FZ |
1444 | return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, |
1445 | BDRV_REQ_ZERO_WRITE | flags); | |
61007b31 SH |
1446 | } |
1447 | ||
1448 | int bdrv_flush_all(void) | |
1449 | { | |
1450 | BlockDriverState *bs = NULL; | |
1451 | int result = 0; | |
1452 | ||
1453 | while ((bs = bdrv_next(bs))) { | |
1454 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1455 | int ret; | |
1456 | ||
1457 | aio_context_acquire(aio_context); | |
1458 | ret = bdrv_flush(bs); | |
1459 | if (ret < 0 && !result) { | |
1460 | result = ret; | |
1461 | } | |
1462 | aio_context_release(aio_context); | |
1463 | } | |
1464 | ||
1465 | return result; | |
1466 | } | |
1467 | ||
1468 | typedef struct BdrvCoGetBlockStatusData { | |
1469 | BlockDriverState *bs; | |
1470 | BlockDriverState *base; | |
67a0fd2a | 1471 | BlockDriverState **file; |
61007b31 SH |
1472 | int64_t sector_num; |
1473 | int nb_sectors; | |
1474 | int *pnum; | |
1475 | int64_t ret; | |
1476 | bool done; | |
1477 | } BdrvCoGetBlockStatusData; | |
1478 | ||
1479 | /* | |
1480 | * Returns the allocation status of the specified sectors. | |
1481 | * Drivers not implementing the functionality are assumed to not support | |
1482 | * backing files, hence all their sectors are reported as allocated. | |
1483 | * | |
1484 | * If 'sector_num' is beyond the end of the disk image the return value is 0 | |
1485 | * and 'pnum' is set to 0. | |
1486 | * | |
1487 | * 'pnum' is set to the number of sectors (including and immediately following | |
1488 | * the specified sector) that are known to be in the same | |
1489 | * allocated/unallocated state. | |
1490 | * | |
1491 | * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes | |
1492 | * beyond the end of the disk image it will be clamped. | |
67a0fd2a FZ |
1493 | * |
1494 | * If returned value is positive and BDRV_BLOCK_OFFSET_VALID bit is set, 'file' | |
1495 | * points to the BDS which the sector range is allocated in. | |
61007b31 SH |
1496 | */ |
1497 | static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, | |
1498 | int64_t sector_num, | |
67a0fd2a FZ |
1499 | int nb_sectors, int *pnum, |
1500 | BlockDriverState **file) | |
61007b31 SH |
1501 | { |
1502 | int64_t total_sectors; | |
1503 | int64_t n; | |
1504 | int64_t ret, ret2; | |
1505 | ||
1506 | total_sectors = bdrv_nb_sectors(bs); | |
1507 | if (total_sectors < 0) { | |
1508 | return total_sectors; | |
1509 | } | |
1510 | ||
1511 | if (sector_num >= total_sectors) { | |
1512 | *pnum = 0; | |
1513 | return 0; | |
1514 | } | |
1515 | ||
1516 | n = total_sectors - sector_num; | |
1517 | if (n < nb_sectors) { | |
1518 | nb_sectors = n; | |
1519 | } | |
1520 | ||
1521 | if (!bs->drv->bdrv_co_get_block_status) { | |
1522 | *pnum = nb_sectors; | |
1523 | ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED; | |
1524 | if (bs->drv->protocol_name) { | |
1525 | ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE); | |
1526 | } | |
1527 | return ret; | |
1528 | } | |
1529 | ||
67a0fd2a FZ |
1530 | *file = NULL; |
1531 | ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum, | |
1532 | file); | |
61007b31 SH |
1533 | if (ret < 0) { |
1534 | *pnum = 0; | |
1535 | return ret; | |
1536 | } | |
1537 | ||
1538 | if (ret & BDRV_BLOCK_RAW) { | |
1539 | assert(ret & BDRV_BLOCK_OFFSET_VALID); | |
9a4f4c31 | 1540 | return bdrv_get_block_status(bs->file->bs, ret >> BDRV_SECTOR_BITS, |
67a0fd2a | 1541 | *pnum, pnum, file); |
61007b31 SH |
1542 | } |
1543 | ||
1544 | if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { | |
1545 | ret |= BDRV_BLOCK_ALLOCATED; | |
a53f1a95 | 1546 | } else { |
61007b31 SH |
1547 | if (bdrv_unallocated_blocks_are_zero(bs)) { |
1548 | ret |= BDRV_BLOCK_ZERO; | |
760e0063 KW |
1549 | } else if (bs->backing) { |
1550 | BlockDriverState *bs2 = bs->backing->bs; | |
61007b31 SH |
1551 | int64_t nb_sectors2 = bdrv_nb_sectors(bs2); |
1552 | if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) { | |
1553 | ret |= BDRV_BLOCK_ZERO; | |
1554 | } | |
1555 | } | |
1556 | } | |
1557 | ||
ac987b30 | 1558 | if (*file && *file != bs && |
61007b31 SH |
1559 | (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && |
1560 | (ret & BDRV_BLOCK_OFFSET_VALID)) { | |
67a0fd2a | 1561 | BlockDriverState *file2; |
61007b31 SH |
1562 | int file_pnum; |
1563 | ||
ac987b30 | 1564 | ret2 = bdrv_co_get_block_status(*file, ret >> BDRV_SECTOR_BITS, |
67a0fd2a | 1565 | *pnum, &file_pnum, &file2); |
61007b31 SH |
1566 | if (ret2 >= 0) { |
1567 | /* Ignore errors. This is just providing extra information, it | |
1568 | * is useful but not necessary. | |
1569 | */ | |
1570 | if (!file_pnum) { | |
1571 | /* !file_pnum indicates an offset at or beyond the EOF; it is | |
1572 | * perfectly valid for the format block driver to point to such | |
1573 | * offsets, so catch it and mark everything as zero */ | |
1574 | ret |= BDRV_BLOCK_ZERO; | |
1575 | } else { | |
1576 | /* Limit request to the range reported by the protocol driver */ | |
1577 | *pnum = file_pnum; | |
1578 | ret |= (ret2 & BDRV_BLOCK_ZERO); | |
1579 | } | |
1580 | } | |
1581 | } | |
1582 | ||
1583 | return ret; | |
1584 | } | |
1585 | ||
ba3f0e25 FZ |
1586 | static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs, |
1587 | BlockDriverState *base, | |
1588 | int64_t sector_num, | |
1589 | int nb_sectors, | |
67a0fd2a FZ |
1590 | int *pnum, |
1591 | BlockDriverState **file) | |
ba3f0e25 FZ |
1592 | { |
1593 | BlockDriverState *p; | |
1594 | int64_t ret = 0; | |
1595 | ||
1596 | assert(bs != base); | |
760e0063 | 1597 | for (p = bs; p != base; p = backing_bs(p)) { |
67a0fd2a | 1598 | ret = bdrv_co_get_block_status(p, sector_num, nb_sectors, pnum, file); |
ba3f0e25 FZ |
1599 | if (ret < 0 || ret & BDRV_BLOCK_ALLOCATED) { |
1600 | break; | |
1601 | } | |
1602 | /* [sector_num, pnum] unallocated on this layer, which could be only | |
1603 | * the first part of [sector_num, nb_sectors]. */ | |
1604 | nb_sectors = MIN(nb_sectors, *pnum); | |
1605 | } | |
1606 | return ret; | |
1607 | } | |
1608 | ||
1609 | /* Coroutine wrapper for bdrv_get_block_status_above() */ | |
1610 | static void coroutine_fn bdrv_get_block_status_above_co_entry(void *opaque) | |
61007b31 SH |
1611 | { |
1612 | BdrvCoGetBlockStatusData *data = opaque; | |
61007b31 | 1613 | |
ba3f0e25 FZ |
1614 | data->ret = bdrv_co_get_block_status_above(data->bs, data->base, |
1615 | data->sector_num, | |
1616 | data->nb_sectors, | |
67a0fd2a FZ |
1617 | data->pnum, |
1618 | data->file); | |
61007b31 SH |
1619 | data->done = true; |
1620 | } | |
1621 | ||
1622 | /* | |
ba3f0e25 | 1623 | * Synchronous wrapper around bdrv_co_get_block_status_above(). |
61007b31 | 1624 | * |
ba3f0e25 | 1625 | * See bdrv_co_get_block_status_above() for details. |
61007b31 | 1626 | */ |
ba3f0e25 FZ |
1627 | int64_t bdrv_get_block_status_above(BlockDriverState *bs, |
1628 | BlockDriverState *base, | |
1629 | int64_t sector_num, | |
67a0fd2a FZ |
1630 | int nb_sectors, int *pnum, |
1631 | BlockDriverState **file) | |
61007b31 SH |
1632 | { |
1633 | Coroutine *co; | |
1634 | BdrvCoGetBlockStatusData data = { | |
1635 | .bs = bs, | |
ba3f0e25 | 1636 | .base = base, |
67a0fd2a | 1637 | .file = file, |
61007b31 SH |
1638 | .sector_num = sector_num, |
1639 | .nb_sectors = nb_sectors, | |
1640 | .pnum = pnum, | |
1641 | .done = false, | |
1642 | }; | |
1643 | ||
1644 | if (qemu_in_coroutine()) { | |
1645 | /* Fast-path if already in coroutine context */ | |
ba3f0e25 | 1646 | bdrv_get_block_status_above_co_entry(&data); |
61007b31 SH |
1647 | } else { |
1648 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1649 | ||
ba3f0e25 | 1650 | co = qemu_coroutine_create(bdrv_get_block_status_above_co_entry); |
61007b31 SH |
1651 | qemu_coroutine_enter(co, &data); |
1652 | while (!data.done) { | |
1653 | aio_poll(aio_context, true); | |
1654 | } | |
1655 | } | |
1656 | return data.ret; | |
1657 | } | |
1658 | ||
ba3f0e25 FZ |
1659 | int64_t bdrv_get_block_status(BlockDriverState *bs, |
1660 | int64_t sector_num, | |
67a0fd2a FZ |
1661 | int nb_sectors, int *pnum, |
1662 | BlockDriverState **file) | |
ba3f0e25 | 1663 | { |
760e0063 | 1664 | return bdrv_get_block_status_above(bs, backing_bs(bs), |
67a0fd2a | 1665 | sector_num, nb_sectors, pnum, file); |
ba3f0e25 FZ |
1666 | } |
1667 | ||
61007b31 SH |
1668 | int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, |
1669 | int nb_sectors, int *pnum) | |
1670 | { | |
67a0fd2a FZ |
1671 | BlockDriverState *file; |
1672 | int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum, | |
1673 | &file); | |
61007b31 SH |
1674 | if (ret < 0) { |
1675 | return ret; | |
1676 | } | |
1677 | return !!(ret & BDRV_BLOCK_ALLOCATED); | |
1678 | } | |
1679 | ||
1680 | /* | |
1681 | * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] | |
1682 | * | |
1683 | * Return true if the given sector is allocated in any image between | |
1684 | * BASE and TOP (inclusive). BASE can be NULL to check if the given | |
1685 | * sector is allocated in any image of the chain. Return false otherwise. | |
1686 | * | |
1687 | * 'pnum' is set to the number of sectors (including and immediately following | |
1688 | * the specified sector) that are known to be in the same | |
1689 | * allocated/unallocated state. | |
1690 | * | |
1691 | */ | |
1692 | int bdrv_is_allocated_above(BlockDriverState *top, | |
1693 | BlockDriverState *base, | |
1694 | int64_t sector_num, | |
1695 | int nb_sectors, int *pnum) | |
1696 | { | |
1697 | BlockDriverState *intermediate; | |
1698 | int ret, n = nb_sectors; | |
1699 | ||
1700 | intermediate = top; | |
1701 | while (intermediate && intermediate != base) { | |
1702 | int pnum_inter; | |
1703 | ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors, | |
1704 | &pnum_inter); | |
1705 | if (ret < 0) { | |
1706 | return ret; | |
1707 | } else if (ret) { | |
1708 | *pnum = pnum_inter; | |
1709 | return 1; | |
1710 | } | |
1711 | ||
1712 | /* | |
1713 | * [sector_num, nb_sectors] is unallocated on top but intermediate | |
1714 | * might have | |
1715 | * | |
1716 | * [sector_num+x, nr_sectors] allocated. | |
1717 | */ | |
1718 | if (n > pnum_inter && | |
1719 | (intermediate == top || | |
1720 | sector_num + pnum_inter < intermediate->total_sectors)) { | |
1721 | n = pnum_inter; | |
1722 | } | |
1723 | ||
760e0063 | 1724 | intermediate = backing_bs(intermediate); |
61007b31 SH |
1725 | } |
1726 | ||
1727 | *pnum = n; | |
1728 | return 0; | |
1729 | } | |
1730 | ||
1731 | int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, | |
1732 | const uint8_t *buf, int nb_sectors) | |
1733 | { | |
1734 | BlockDriver *drv = bs->drv; | |
1735 | int ret; | |
1736 | ||
1737 | if (!drv) { | |
1738 | return -ENOMEDIUM; | |
1739 | } | |
1740 | if (!drv->bdrv_write_compressed) { | |
1741 | return -ENOTSUP; | |
1742 | } | |
1743 | ret = bdrv_check_request(bs, sector_num, nb_sectors); | |
1744 | if (ret < 0) { | |
1745 | return ret; | |
1746 | } | |
1747 | ||
1748 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
1749 | ||
1750 | return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); | |
1751 | } | |
1752 | ||
1753 | int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, | |
1754 | int64_t pos, int size) | |
1755 | { | |
1756 | QEMUIOVector qiov; | |
1757 | struct iovec iov = { | |
1758 | .iov_base = (void *) buf, | |
1759 | .iov_len = size, | |
1760 | }; | |
1761 | ||
1762 | qemu_iovec_init_external(&qiov, &iov, 1); | |
1763 | return bdrv_writev_vmstate(bs, &qiov, pos); | |
1764 | } | |
1765 | ||
1766 | int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) | |
1767 | { | |
1768 | BlockDriver *drv = bs->drv; | |
1769 | ||
1770 | if (!drv) { | |
1771 | return -ENOMEDIUM; | |
1772 | } else if (drv->bdrv_save_vmstate) { | |
1773 | return drv->bdrv_save_vmstate(bs, qiov, pos); | |
1774 | } else if (bs->file) { | |
9a4f4c31 | 1775 | return bdrv_writev_vmstate(bs->file->bs, qiov, pos); |
61007b31 SH |
1776 | } |
1777 | ||
1778 | return -ENOTSUP; | |
1779 | } | |
1780 | ||
1781 | int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, | |
1782 | int64_t pos, int size) | |
1783 | { | |
1784 | BlockDriver *drv = bs->drv; | |
1785 | if (!drv) | |
1786 | return -ENOMEDIUM; | |
1787 | if (drv->bdrv_load_vmstate) | |
1788 | return drv->bdrv_load_vmstate(bs, buf, pos, size); | |
1789 | if (bs->file) | |
9a4f4c31 | 1790 | return bdrv_load_vmstate(bs->file->bs, buf, pos, size); |
61007b31 SH |
1791 | return -ENOTSUP; |
1792 | } | |
1793 | ||
1794 | /**************************************************************/ | |
1795 | /* async I/Os */ | |
1796 | ||
1797 | BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, | |
1798 | QEMUIOVector *qiov, int nb_sectors, | |
1799 | BlockCompletionFunc *cb, void *opaque) | |
1800 | { | |
1801 | trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); | |
1802 | ||
1803 | return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, | |
1804 | cb, opaque, false); | |
1805 | } | |
1806 | ||
1807 | BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, | |
1808 | QEMUIOVector *qiov, int nb_sectors, | |
1809 | BlockCompletionFunc *cb, void *opaque) | |
1810 | { | |
1811 | trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); | |
1812 | ||
1813 | return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, | |
1814 | cb, opaque, true); | |
1815 | } | |
1816 | ||
1817 | BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, | |
1818 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags, | |
1819 | BlockCompletionFunc *cb, void *opaque) | |
1820 | { | |
1821 | trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque); | |
1822 | ||
1823 | return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors, | |
1824 | BDRV_REQ_ZERO_WRITE | flags, | |
1825 | cb, opaque, true); | |
1826 | } | |
1827 | ||
1828 | ||
1829 | typedef struct MultiwriteCB { | |
1830 | int error; | |
1831 | int num_requests; | |
1832 | int num_callbacks; | |
1833 | struct { | |
1834 | BlockCompletionFunc *cb; | |
1835 | void *opaque; | |
1836 | QEMUIOVector *free_qiov; | |
1837 | } callbacks[]; | |
1838 | } MultiwriteCB; | |
1839 | ||
1840 | static void multiwrite_user_cb(MultiwriteCB *mcb) | |
1841 | { | |
1842 | int i; | |
1843 | ||
1844 | for (i = 0; i < mcb->num_callbacks; i++) { | |
1845 | mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); | |
1846 | if (mcb->callbacks[i].free_qiov) { | |
1847 | qemu_iovec_destroy(mcb->callbacks[i].free_qiov); | |
1848 | } | |
1849 | g_free(mcb->callbacks[i].free_qiov); | |
1850 | } | |
1851 | } | |
1852 | ||
1853 | static void multiwrite_cb(void *opaque, int ret) | |
1854 | { | |
1855 | MultiwriteCB *mcb = opaque; | |
1856 | ||
1857 | trace_multiwrite_cb(mcb, ret); | |
1858 | ||
1859 | if (ret < 0 && !mcb->error) { | |
1860 | mcb->error = ret; | |
1861 | } | |
1862 | ||
1863 | mcb->num_requests--; | |
1864 | if (mcb->num_requests == 0) { | |
1865 | multiwrite_user_cb(mcb); | |
1866 | g_free(mcb); | |
1867 | } | |
1868 | } | |
1869 | ||
1870 | static int multiwrite_req_compare(const void *a, const void *b) | |
1871 | { | |
1872 | const BlockRequest *req1 = a, *req2 = b; | |
1873 | ||
1874 | /* | |
1875 | * Note that we can't simply subtract req2->sector from req1->sector | |
1876 | * here as that could overflow the return value. | |
1877 | */ | |
1878 | if (req1->sector > req2->sector) { | |
1879 | return 1; | |
1880 | } else if (req1->sector < req2->sector) { | |
1881 | return -1; | |
1882 | } else { | |
1883 | return 0; | |
1884 | } | |
1885 | } | |
1886 | ||
1887 | /* | |
1888 | * Takes a bunch of requests and tries to merge them. Returns the number of | |
1889 | * requests that remain after merging. | |
1890 | */ | |
1891 | static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, | |
1892 | int num_reqs, MultiwriteCB *mcb) | |
1893 | { | |
1894 | int i, outidx; | |
1895 | ||
1896 | // Sort requests by start sector | |
1897 | qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); | |
1898 | ||
1899 | // Check if adjacent requests touch the same clusters. If so, combine them, | |
1900 | // filling up gaps with zero sectors. | |
1901 | outidx = 0; | |
1902 | for (i = 1; i < num_reqs; i++) { | |
1903 | int merge = 0; | |
1904 | int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; | |
1905 | ||
1906 | // Handle exactly sequential writes and overlapping writes. | |
1907 | if (reqs[i].sector <= oldreq_last) { | |
1908 | merge = 1; | |
1909 | } | |
1910 | ||
222565f6 SH |
1911 | if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > |
1912 | bs->bl.max_iov) { | |
61007b31 SH |
1913 | merge = 0; |
1914 | } | |
1915 | ||
1916 | if (bs->bl.max_transfer_length && reqs[outidx].nb_sectors + | |
1917 | reqs[i].nb_sectors > bs->bl.max_transfer_length) { | |
1918 | merge = 0; | |
1919 | } | |
1920 | ||
1921 | if (merge) { | |
1922 | size_t size; | |
1923 | QEMUIOVector *qiov = g_malloc0(sizeof(*qiov)); | |
1924 | qemu_iovec_init(qiov, | |
1925 | reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); | |
1926 | ||
1927 | // Add the first request to the merged one. If the requests are | |
1928 | // overlapping, drop the last sectors of the first request. | |
1929 | size = (reqs[i].sector - reqs[outidx].sector) << 9; | |
1930 | qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); | |
1931 | ||
1932 | // We should need to add any zeros between the two requests | |
1933 | assert (reqs[i].sector <= oldreq_last); | |
1934 | ||
1935 | // Add the second request | |
1936 | qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); | |
1937 | ||
1938 | // Add tail of first request, if necessary | |
1939 | if (qiov->size < reqs[outidx].qiov->size) { | |
1940 | qemu_iovec_concat(qiov, reqs[outidx].qiov, qiov->size, | |
1941 | reqs[outidx].qiov->size - qiov->size); | |
1942 | } | |
1943 | ||
1944 | reqs[outidx].nb_sectors = qiov->size >> 9; | |
1945 | reqs[outidx].qiov = qiov; | |
1946 | ||
1947 | mcb->callbacks[i].free_qiov = reqs[outidx].qiov; | |
1948 | } else { | |
1949 | outidx++; | |
1950 | reqs[outidx].sector = reqs[i].sector; | |
1951 | reqs[outidx].nb_sectors = reqs[i].nb_sectors; | |
1952 | reqs[outidx].qiov = reqs[i].qiov; | |
1953 | } | |
1954 | } | |
1955 | ||
7f0e9da6 HR |
1956 | if (bs->blk) { |
1957 | block_acct_merge_done(blk_get_stats(bs->blk), BLOCK_ACCT_WRITE, | |
1958 | num_reqs - outidx - 1); | |
1959 | } | |
61007b31 SH |
1960 | |
1961 | return outidx + 1; | |
1962 | } | |
1963 | ||
1964 | /* | |
1965 | * Submit multiple AIO write requests at once. | |
1966 | * | |
1967 | * On success, the function returns 0 and all requests in the reqs array have | |
1968 | * been submitted. In error case this function returns -1, and any of the | |
1969 | * requests may or may not be submitted yet. In particular, this means that the | |
1970 | * callback will be called for some of the requests, for others it won't. The | |
1971 | * caller must check the error field of the BlockRequest to wait for the right | |
1972 | * callbacks (if error != 0, no callback will be called). | |
1973 | * | |
1974 | * The implementation may modify the contents of the reqs array, e.g. to merge | |
1975 | * requests. However, the fields opaque and error are left unmodified as they | |
1976 | * are used to signal failure for a single request to the caller. | |
1977 | */ | |
1978 | int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) | |
1979 | { | |
1980 | MultiwriteCB *mcb; | |
1981 | int i; | |
1982 | ||
1983 | /* don't submit writes if we don't have a medium */ | |
1984 | if (bs->drv == NULL) { | |
1985 | for (i = 0; i < num_reqs; i++) { | |
1986 | reqs[i].error = -ENOMEDIUM; | |
1987 | } | |
1988 | return -1; | |
1989 | } | |
1990 | ||
1991 | if (num_reqs == 0) { | |
1992 | return 0; | |
1993 | } | |
1994 | ||
1995 | // Create MultiwriteCB structure | |
1996 | mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); | |
1997 | mcb->num_requests = 0; | |
1998 | mcb->num_callbacks = num_reqs; | |
1999 | ||
2000 | for (i = 0; i < num_reqs; i++) { | |
2001 | mcb->callbacks[i].cb = reqs[i].cb; | |
2002 | mcb->callbacks[i].opaque = reqs[i].opaque; | |
2003 | } | |
2004 | ||
2005 | // Check for mergable requests | |
2006 | num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); | |
2007 | ||
2008 | trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); | |
2009 | ||
2010 | /* Run the aio requests. */ | |
2011 | mcb->num_requests = num_reqs; | |
2012 | for (i = 0; i < num_reqs; i++) { | |
2013 | bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov, | |
2014 | reqs[i].nb_sectors, reqs[i].flags, | |
2015 | multiwrite_cb, mcb, | |
2016 | true); | |
2017 | } | |
2018 | ||
2019 | return 0; | |
2020 | } | |
2021 | ||
2022 | void bdrv_aio_cancel(BlockAIOCB *acb) | |
2023 | { | |
2024 | qemu_aio_ref(acb); | |
2025 | bdrv_aio_cancel_async(acb); | |
2026 | while (acb->refcnt > 1) { | |
2027 | if (acb->aiocb_info->get_aio_context) { | |
2028 | aio_poll(acb->aiocb_info->get_aio_context(acb), true); | |
2029 | } else if (acb->bs) { | |
2030 | aio_poll(bdrv_get_aio_context(acb->bs), true); | |
2031 | } else { | |
2032 | abort(); | |
2033 | } | |
2034 | } | |
2035 | qemu_aio_unref(acb); | |
2036 | } | |
2037 | ||
2038 | /* Async version of aio cancel. The caller is not blocked if the acb implements | |
2039 | * cancel_async, otherwise we do nothing and let the request normally complete. | |
2040 | * In either case the completion callback must be called. */ | |
2041 | void bdrv_aio_cancel_async(BlockAIOCB *acb) | |
2042 | { | |
2043 | if (acb->aiocb_info->cancel_async) { | |
2044 | acb->aiocb_info->cancel_async(acb); | |
2045 | } | |
2046 | } | |
2047 | ||
2048 | /**************************************************************/ | |
2049 | /* async block device emulation */ | |
2050 | ||
2051 | typedef struct BlockAIOCBSync { | |
2052 | BlockAIOCB common; | |
2053 | QEMUBH *bh; | |
2054 | int ret; | |
2055 | /* vector translation state */ | |
2056 | QEMUIOVector *qiov; | |
2057 | uint8_t *bounce; | |
2058 | int is_write; | |
2059 | } BlockAIOCBSync; | |
2060 | ||
2061 | static const AIOCBInfo bdrv_em_aiocb_info = { | |
2062 | .aiocb_size = sizeof(BlockAIOCBSync), | |
2063 | }; | |
2064 | ||
2065 | static void bdrv_aio_bh_cb(void *opaque) | |
2066 | { | |
2067 | BlockAIOCBSync *acb = opaque; | |
2068 | ||
2069 | if (!acb->is_write && acb->ret >= 0) { | |
2070 | qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); | |
2071 | } | |
2072 | qemu_vfree(acb->bounce); | |
2073 | acb->common.cb(acb->common.opaque, acb->ret); | |
2074 | qemu_bh_delete(acb->bh); | |
2075 | acb->bh = NULL; | |
2076 | qemu_aio_unref(acb); | |
2077 | } | |
2078 | ||
2079 | static BlockAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, | |
2080 | int64_t sector_num, | |
2081 | QEMUIOVector *qiov, | |
2082 | int nb_sectors, | |
2083 | BlockCompletionFunc *cb, | |
2084 | void *opaque, | |
2085 | int is_write) | |
2086 | ||
2087 | { | |
2088 | BlockAIOCBSync *acb; | |
2089 | ||
2090 | acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque); | |
2091 | acb->is_write = is_write; | |
2092 | acb->qiov = qiov; | |
2093 | acb->bounce = qemu_try_blockalign(bs, qiov->size); | |
2094 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb); | |
2095 | ||
2096 | if (acb->bounce == NULL) { | |
2097 | acb->ret = -ENOMEM; | |
2098 | } else if (is_write) { | |
2099 | qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); | |
2100 | acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); | |
2101 | } else { | |
2102 | acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); | |
2103 | } | |
2104 | ||
2105 | qemu_bh_schedule(acb->bh); | |
2106 | ||
2107 | return &acb->common; | |
2108 | } | |
2109 | ||
2110 | static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, | |
2111 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
2112 | BlockCompletionFunc *cb, void *opaque) | |
2113 | { | |
2114 | return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); | |
2115 | } | |
2116 | ||
2117 | static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, | |
2118 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
2119 | BlockCompletionFunc *cb, void *opaque) | |
2120 | { | |
2121 | return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); | |
2122 | } | |
2123 | ||
2124 | ||
2125 | typedef struct BlockAIOCBCoroutine { | |
2126 | BlockAIOCB common; | |
2127 | BlockRequest req; | |
2128 | bool is_write; | |
2129 | bool need_bh; | |
2130 | bool *done; | |
2131 | QEMUBH* bh; | |
2132 | } BlockAIOCBCoroutine; | |
2133 | ||
2134 | static const AIOCBInfo bdrv_em_co_aiocb_info = { | |
2135 | .aiocb_size = sizeof(BlockAIOCBCoroutine), | |
2136 | }; | |
2137 | ||
2138 | static void bdrv_co_complete(BlockAIOCBCoroutine *acb) | |
2139 | { | |
2140 | if (!acb->need_bh) { | |
2141 | acb->common.cb(acb->common.opaque, acb->req.error); | |
2142 | qemu_aio_unref(acb); | |
2143 | } | |
2144 | } | |
2145 | ||
2146 | static void bdrv_co_em_bh(void *opaque) | |
2147 | { | |
2148 | BlockAIOCBCoroutine *acb = opaque; | |
2149 | ||
2150 | assert(!acb->need_bh); | |
2151 | qemu_bh_delete(acb->bh); | |
2152 | bdrv_co_complete(acb); | |
2153 | } | |
2154 | ||
2155 | static void bdrv_co_maybe_schedule_bh(BlockAIOCBCoroutine *acb) | |
2156 | { | |
2157 | acb->need_bh = false; | |
2158 | if (acb->req.error != -EINPROGRESS) { | |
2159 | BlockDriverState *bs = acb->common.bs; | |
2160 | ||
2161 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); | |
2162 | qemu_bh_schedule(acb->bh); | |
2163 | } | |
2164 | } | |
2165 | ||
2166 | /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */ | |
2167 | static void coroutine_fn bdrv_co_do_rw(void *opaque) | |
2168 | { | |
2169 | BlockAIOCBCoroutine *acb = opaque; | |
2170 | BlockDriverState *bs = acb->common.bs; | |
2171 | ||
2172 | if (!acb->is_write) { | |
2173 | acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, | |
2174 | acb->req.nb_sectors, acb->req.qiov, acb->req.flags); | |
2175 | } else { | |
2176 | acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, | |
2177 | acb->req.nb_sectors, acb->req.qiov, acb->req.flags); | |
2178 | } | |
2179 | ||
2180 | bdrv_co_complete(acb); | |
2181 | } | |
2182 | ||
2183 | static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, | |
2184 | int64_t sector_num, | |
2185 | QEMUIOVector *qiov, | |
2186 | int nb_sectors, | |
2187 | BdrvRequestFlags flags, | |
2188 | BlockCompletionFunc *cb, | |
2189 | void *opaque, | |
2190 | bool is_write) | |
2191 | { | |
2192 | Coroutine *co; | |
2193 | BlockAIOCBCoroutine *acb; | |
2194 | ||
2195 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
2196 | acb->need_bh = true; | |
2197 | acb->req.error = -EINPROGRESS; | |
2198 | acb->req.sector = sector_num; | |
2199 | acb->req.nb_sectors = nb_sectors; | |
2200 | acb->req.qiov = qiov; | |
2201 | acb->req.flags = flags; | |
2202 | acb->is_write = is_write; | |
2203 | ||
2204 | co = qemu_coroutine_create(bdrv_co_do_rw); | |
2205 | qemu_coroutine_enter(co, acb); | |
2206 | ||
2207 | bdrv_co_maybe_schedule_bh(acb); | |
2208 | return &acb->common; | |
2209 | } | |
2210 | ||
2211 | static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) | |
2212 | { | |
2213 | BlockAIOCBCoroutine *acb = opaque; | |
2214 | BlockDriverState *bs = acb->common.bs; | |
2215 | ||
2216 | acb->req.error = bdrv_co_flush(bs); | |
2217 | bdrv_co_complete(acb); | |
2218 | } | |
2219 | ||
2220 | BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs, | |
2221 | BlockCompletionFunc *cb, void *opaque) | |
2222 | { | |
2223 | trace_bdrv_aio_flush(bs, opaque); | |
2224 | ||
2225 | Coroutine *co; | |
2226 | BlockAIOCBCoroutine *acb; | |
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 | ||
2232 | co = qemu_coroutine_create(bdrv_aio_flush_co_entry); | |
2233 | qemu_coroutine_enter(co, acb); | |
2234 | ||
2235 | bdrv_co_maybe_schedule_bh(acb); | |
2236 | return &acb->common; | |
2237 | } | |
2238 | ||
2239 | static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) | |
2240 | { | |
2241 | BlockAIOCBCoroutine *acb = opaque; | |
2242 | BlockDriverState *bs = acb->common.bs; | |
2243 | ||
2244 | acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); | |
2245 | bdrv_co_complete(acb); | |
2246 | } | |
2247 | ||
2248 | BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs, | |
2249 | int64_t sector_num, int nb_sectors, | |
2250 | BlockCompletionFunc *cb, void *opaque) | |
2251 | { | |
2252 | Coroutine *co; | |
2253 | BlockAIOCBCoroutine *acb; | |
2254 | ||
2255 | trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); | |
2256 | ||
2257 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
2258 | acb->need_bh = true; | |
2259 | acb->req.error = -EINPROGRESS; | |
2260 | acb->req.sector = sector_num; | |
2261 | acb->req.nb_sectors = nb_sectors; | |
2262 | co = qemu_coroutine_create(bdrv_aio_discard_co_entry); | |
2263 | qemu_coroutine_enter(co, acb); | |
2264 | ||
2265 | bdrv_co_maybe_schedule_bh(acb); | |
2266 | return &acb->common; | |
2267 | } | |
2268 | ||
2269 | void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs, | |
2270 | BlockCompletionFunc *cb, void *opaque) | |
2271 | { | |
2272 | BlockAIOCB *acb; | |
2273 | ||
c84b3192 | 2274 | acb = g_malloc(aiocb_info->aiocb_size); |
61007b31 SH |
2275 | acb->aiocb_info = aiocb_info; |
2276 | acb->bs = bs; | |
2277 | acb->cb = cb; | |
2278 | acb->opaque = opaque; | |
2279 | acb->refcnt = 1; | |
2280 | return acb; | |
2281 | } | |
2282 | ||
2283 | void qemu_aio_ref(void *p) | |
2284 | { | |
2285 | BlockAIOCB *acb = p; | |
2286 | acb->refcnt++; | |
2287 | } | |
2288 | ||
2289 | void qemu_aio_unref(void *p) | |
2290 | { | |
2291 | BlockAIOCB *acb = p; | |
2292 | assert(acb->refcnt > 0); | |
2293 | if (--acb->refcnt == 0) { | |
c84b3192 | 2294 | g_free(acb); |
61007b31 SH |
2295 | } |
2296 | } | |
2297 | ||
2298 | /**************************************************************/ | |
2299 | /* Coroutine block device emulation */ | |
2300 | ||
2301 | typedef struct CoroutineIOCompletion { | |
2302 | Coroutine *coroutine; | |
2303 | int ret; | |
2304 | } CoroutineIOCompletion; | |
2305 | ||
2306 | static void bdrv_co_io_em_complete(void *opaque, int ret) | |
2307 | { | |
2308 | CoroutineIOCompletion *co = opaque; | |
2309 | ||
2310 | co->ret = ret; | |
2311 | qemu_coroutine_enter(co->coroutine, NULL); | |
2312 | } | |
2313 | ||
2314 | static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, | |
2315 | int nb_sectors, QEMUIOVector *iov, | |
2316 | bool is_write) | |
2317 | { | |
2318 | CoroutineIOCompletion co = { | |
2319 | .coroutine = qemu_coroutine_self(), | |
2320 | }; | |
2321 | BlockAIOCB *acb; | |
2322 | ||
2323 | if (is_write) { | |
2324 | acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, | |
2325 | bdrv_co_io_em_complete, &co); | |
2326 | } else { | |
2327 | acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, | |
2328 | bdrv_co_io_em_complete, &co); | |
2329 | } | |
2330 | ||
2331 | trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); | |
2332 | if (!acb) { | |
2333 | return -EIO; | |
2334 | } | |
2335 | qemu_coroutine_yield(); | |
2336 | ||
2337 | return co.ret; | |
2338 | } | |
2339 | ||
2340 | static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, | |
2341 | int64_t sector_num, int nb_sectors, | |
2342 | QEMUIOVector *iov) | |
2343 | { | |
2344 | return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); | |
2345 | } | |
2346 | ||
2347 | static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, | |
2348 | int64_t sector_num, int nb_sectors, | |
2349 | QEMUIOVector *iov) | |
2350 | { | |
2351 | return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); | |
2352 | } | |
2353 | ||
2354 | static void coroutine_fn bdrv_flush_co_entry(void *opaque) | |
2355 | { | |
2356 | RwCo *rwco = opaque; | |
2357 | ||
2358 | rwco->ret = bdrv_co_flush(rwco->bs); | |
2359 | } | |
2360 | ||
2361 | int coroutine_fn bdrv_co_flush(BlockDriverState *bs) | |
2362 | { | |
2363 | int ret; | |
cdb5e315 | 2364 | BdrvTrackedRequest req; |
61007b31 | 2365 | |
1b6bc94d DA |
2366 | if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || |
2367 | bdrv_is_sg(bs)) { | |
61007b31 SH |
2368 | return 0; |
2369 | } | |
2370 | ||
cdb5e315 | 2371 | tracked_request_begin(&req, bs, 0, 0, BDRV_TRACKED_FLUSH); |
61007b31 SH |
2372 | /* Write back cached data to the OS even with cache=unsafe */ |
2373 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); | |
2374 | if (bs->drv->bdrv_co_flush_to_os) { | |
2375 | ret = bs->drv->bdrv_co_flush_to_os(bs); | |
2376 | if (ret < 0) { | |
cdb5e315 | 2377 | goto out; |
61007b31 SH |
2378 | } |
2379 | } | |
2380 | ||
2381 | /* But don't actually force it to the disk with cache=unsafe */ | |
2382 | if (bs->open_flags & BDRV_O_NO_FLUSH) { | |
2383 | goto flush_parent; | |
2384 | } | |
2385 | ||
2386 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); | |
2387 | if (bs->drv->bdrv_co_flush_to_disk) { | |
2388 | ret = bs->drv->bdrv_co_flush_to_disk(bs); | |
2389 | } else if (bs->drv->bdrv_aio_flush) { | |
2390 | BlockAIOCB *acb; | |
2391 | CoroutineIOCompletion co = { | |
2392 | .coroutine = qemu_coroutine_self(), | |
2393 | }; | |
2394 | ||
2395 | acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); | |
2396 | if (acb == NULL) { | |
2397 | ret = -EIO; | |
2398 | } else { | |
2399 | qemu_coroutine_yield(); | |
2400 | ret = co.ret; | |
2401 | } | |
2402 | } else { | |
2403 | /* | |
2404 | * Some block drivers always operate in either writethrough or unsafe | |
2405 | * mode and don't support bdrv_flush therefore. Usually qemu doesn't | |
2406 | * know how the server works (because the behaviour is hardcoded or | |
2407 | * depends on server-side configuration), so we can't ensure that | |
2408 | * everything is safe on disk. Returning an error doesn't work because | |
2409 | * that would break guests even if the server operates in writethrough | |
2410 | * mode. | |
2411 | * | |
2412 | * Let's hope the user knows what he's doing. | |
2413 | */ | |
2414 | ret = 0; | |
2415 | } | |
2416 | if (ret < 0) { | |
cdb5e315 | 2417 | goto out; |
61007b31 SH |
2418 | } |
2419 | ||
2420 | /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH | |
2421 | * in the case of cache=unsafe, so there are no useless flushes. | |
2422 | */ | |
2423 | flush_parent: | |
cdb5e315 FZ |
2424 | ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0; |
2425 | out: | |
2426 | tracked_request_end(&req); | |
2427 | return ret; | |
61007b31 SH |
2428 | } |
2429 | ||
2430 | int bdrv_flush(BlockDriverState *bs) | |
2431 | { | |
2432 | Coroutine *co; | |
2433 | RwCo rwco = { | |
2434 | .bs = bs, | |
2435 | .ret = NOT_DONE, | |
2436 | }; | |
2437 | ||
2438 | if (qemu_in_coroutine()) { | |
2439 | /* Fast-path if already in coroutine context */ | |
2440 | bdrv_flush_co_entry(&rwco); | |
2441 | } else { | |
2442 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2443 | ||
2444 | co = qemu_coroutine_create(bdrv_flush_co_entry); | |
2445 | qemu_coroutine_enter(co, &rwco); | |
2446 | while (rwco.ret == NOT_DONE) { | |
2447 | aio_poll(aio_context, true); | |
2448 | } | |
2449 | } | |
2450 | ||
2451 | return rwco.ret; | |
2452 | } | |
2453 | ||
2454 | typedef struct DiscardCo { | |
2455 | BlockDriverState *bs; | |
2456 | int64_t sector_num; | |
2457 | int nb_sectors; | |
2458 | int ret; | |
2459 | } DiscardCo; | |
2460 | static void coroutine_fn bdrv_discard_co_entry(void *opaque) | |
2461 | { | |
2462 | DiscardCo *rwco = opaque; | |
2463 | ||
2464 | rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); | |
2465 | } | |
2466 | ||
2467 | int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, | |
2468 | int nb_sectors) | |
2469 | { | |
b1066c87 | 2470 | BdrvTrackedRequest req; |
61007b31 SH |
2471 | int max_discard, ret; |
2472 | ||
2473 | if (!bs->drv) { | |
2474 | return -ENOMEDIUM; | |
2475 | } | |
2476 | ||
2477 | ret = bdrv_check_request(bs, sector_num, nb_sectors); | |
2478 | if (ret < 0) { | |
2479 | return ret; | |
2480 | } else if (bs->read_only) { | |
eaf5fe2d | 2481 | return -EPERM; |
61007b31 | 2482 | } |
04c01a5c | 2483 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); |
61007b31 | 2484 | |
61007b31 SH |
2485 | /* Do nothing if disabled. */ |
2486 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
2487 | return 0; | |
2488 | } | |
2489 | ||
2490 | if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) { | |
2491 | return 0; | |
2492 | } | |
2493 | ||
b1066c87 FZ |
2494 | tracked_request_begin(&req, bs, sector_num, nb_sectors, |
2495 | BDRV_TRACKED_DISCARD); | |
50824995 FZ |
2496 | bdrv_set_dirty(bs, sector_num, nb_sectors); |
2497 | ||
61007b31 SH |
2498 | max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS); |
2499 | while (nb_sectors > 0) { | |
2500 | int ret; | |
2501 | int num = nb_sectors; | |
2502 | ||
2503 | /* align request */ | |
2504 | if (bs->bl.discard_alignment && | |
2505 | num >= bs->bl.discard_alignment && | |
2506 | sector_num % bs->bl.discard_alignment) { | |
2507 | if (num > bs->bl.discard_alignment) { | |
2508 | num = bs->bl.discard_alignment; | |
2509 | } | |
2510 | num -= sector_num % bs->bl.discard_alignment; | |
2511 | } | |
2512 | ||
2513 | /* limit request size */ | |
2514 | if (num > max_discard) { | |
2515 | num = max_discard; | |
2516 | } | |
2517 | ||
2518 | if (bs->drv->bdrv_co_discard) { | |
2519 | ret = bs->drv->bdrv_co_discard(bs, sector_num, num); | |
2520 | } else { | |
2521 | BlockAIOCB *acb; | |
2522 | CoroutineIOCompletion co = { | |
2523 | .coroutine = qemu_coroutine_self(), | |
2524 | }; | |
2525 | ||
2526 | acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, | |
2527 | bdrv_co_io_em_complete, &co); | |
2528 | if (acb == NULL) { | |
b1066c87 FZ |
2529 | ret = -EIO; |
2530 | goto out; | |
61007b31 SH |
2531 | } else { |
2532 | qemu_coroutine_yield(); | |
2533 | ret = co.ret; | |
2534 | } | |
2535 | } | |
2536 | if (ret && ret != -ENOTSUP) { | |
b1066c87 | 2537 | goto out; |
61007b31 SH |
2538 | } |
2539 | ||
2540 | sector_num += num; | |
2541 | nb_sectors -= num; | |
2542 | } | |
b1066c87 FZ |
2543 | ret = 0; |
2544 | out: | |
2545 | tracked_request_end(&req); | |
2546 | return ret; | |
61007b31 SH |
2547 | } |
2548 | ||
2549 | int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) | |
2550 | { | |
2551 | Coroutine *co; | |
2552 | DiscardCo rwco = { | |
2553 | .bs = bs, | |
2554 | .sector_num = sector_num, | |
2555 | .nb_sectors = nb_sectors, | |
2556 | .ret = NOT_DONE, | |
2557 | }; | |
2558 | ||
2559 | if (qemu_in_coroutine()) { | |
2560 | /* Fast-path if already in coroutine context */ | |
2561 | bdrv_discard_co_entry(&rwco); | |
2562 | } else { | |
2563 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2564 | ||
2565 | co = qemu_coroutine_create(bdrv_discard_co_entry); | |
2566 | qemu_coroutine_enter(co, &rwco); | |
2567 | while (rwco.ret == NOT_DONE) { | |
2568 | aio_poll(aio_context, true); | |
2569 | } | |
2570 | } | |
2571 | ||
2572 | return rwco.ret; | |
2573 | } | |
2574 | ||
5c5ae76a FZ |
2575 | typedef struct { |
2576 | CoroutineIOCompletion *co; | |
2577 | QEMUBH *bh; | |
2578 | } BdrvIoctlCompletionData; | |
61007b31 | 2579 | |
5c5ae76a FZ |
2580 | static void bdrv_ioctl_bh_cb(void *opaque) |
2581 | { | |
2582 | BdrvIoctlCompletionData *data = opaque; | |
2583 | ||
2584 | bdrv_co_io_em_complete(data->co, -ENOTSUP); | |
2585 | qemu_bh_delete(data->bh); | |
2586 | } | |
2587 | ||
2588 | static int bdrv_co_do_ioctl(BlockDriverState *bs, int req, void *buf) | |
61007b31 SH |
2589 | { |
2590 | BlockDriver *drv = bs->drv; | |
5c5ae76a FZ |
2591 | BdrvTrackedRequest tracked_req; |
2592 | CoroutineIOCompletion co = { | |
2593 | .coroutine = qemu_coroutine_self(), | |
2594 | }; | |
2595 | BlockAIOCB *acb; | |
61007b31 | 2596 | |
5c5ae76a FZ |
2597 | tracked_request_begin(&tracked_req, bs, 0, 0, BDRV_TRACKED_IOCTL); |
2598 | if (!drv || !drv->bdrv_aio_ioctl) { | |
2599 | co.ret = -ENOTSUP; | |
2600 | goto out; | |
2601 | } | |
2602 | ||
2603 | acb = drv->bdrv_aio_ioctl(bs, req, buf, bdrv_co_io_em_complete, &co); | |
2604 | if (!acb) { | |
2605 | BdrvIoctlCompletionData *data = g_new(BdrvIoctlCompletionData, 1); | |
2606 | data->bh = aio_bh_new(bdrv_get_aio_context(bs), | |
2607 | bdrv_ioctl_bh_cb, data); | |
2608 | data->co = &co; | |
2609 | qemu_bh_schedule(data->bh); | |
2610 | } | |
2611 | qemu_coroutine_yield(); | |
2612 | out: | |
2613 | tracked_request_end(&tracked_req); | |
2614 | return co.ret; | |
2615 | } | |
2616 | ||
2617 | typedef struct { | |
2618 | BlockDriverState *bs; | |
2619 | int req; | |
2620 | void *buf; | |
2621 | int ret; | |
2622 | } BdrvIoctlCoData; | |
2623 | ||
2624 | static void coroutine_fn bdrv_co_ioctl_entry(void *opaque) | |
2625 | { | |
2626 | BdrvIoctlCoData *data = opaque; | |
2627 | data->ret = bdrv_co_do_ioctl(data->bs, data->req, data->buf); | |
2628 | } | |
2629 | ||
2630 | /* needed for generic scsi interface */ | |
2631 | int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) | |
2632 | { | |
2633 | BdrvIoctlCoData data = { | |
2634 | .bs = bs, | |
2635 | .req = req, | |
2636 | .buf = buf, | |
2637 | .ret = -EINPROGRESS, | |
2638 | }; | |
2639 | ||
2640 | if (qemu_in_coroutine()) { | |
2641 | /* Fast-path if already in coroutine context */ | |
2642 | bdrv_co_ioctl_entry(&data); | |
2643 | } else { | |
2644 | Coroutine *co = qemu_coroutine_create(bdrv_co_ioctl_entry); | |
ba889444 | 2645 | |
5c5ae76a | 2646 | qemu_coroutine_enter(co, &data); |
ba889444 PB |
2647 | while (data.ret == -EINPROGRESS) { |
2648 | aio_poll(bdrv_get_aio_context(bs), true); | |
2649 | } | |
5c5ae76a FZ |
2650 | } |
2651 | return data.ret; | |
2652 | } | |
2653 | ||
2654 | static void coroutine_fn bdrv_co_aio_ioctl_entry(void *opaque) | |
2655 | { | |
2656 | BlockAIOCBCoroutine *acb = opaque; | |
2657 | acb->req.error = bdrv_co_do_ioctl(acb->common.bs, | |
2658 | acb->req.req, acb->req.buf); | |
2659 | bdrv_co_complete(acb); | |
61007b31 SH |
2660 | } |
2661 | ||
2662 | BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, | |
2663 | unsigned long int req, void *buf, | |
2664 | BlockCompletionFunc *cb, void *opaque) | |
2665 | { | |
5c5ae76a FZ |
2666 | BlockAIOCBCoroutine *acb = qemu_aio_get(&bdrv_em_co_aiocb_info, |
2667 | bs, cb, opaque); | |
2668 | Coroutine *co; | |
61007b31 | 2669 | |
5c5ae76a FZ |
2670 | acb->need_bh = true; |
2671 | acb->req.error = -EINPROGRESS; | |
2672 | acb->req.req = req; | |
2673 | acb->req.buf = buf; | |
2674 | co = qemu_coroutine_create(bdrv_co_aio_ioctl_entry); | |
2675 | qemu_coroutine_enter(co, acb); | |
2676 | ||
2677 | bdrv_co_maybe_schedule_bh(acb); | |
2678 | return &acb->common; | |
61007b31 SH |
2679 | } |
2680 | ||
2681 | void *qemu_blockalign(BlockDriverState *bs, size_t size) | |
2682 | { | |
2683 | return qemu_memalign(bdrv_opt_mem_align(bs), size); | |
2684 | } | |
2685 | ||
2686 | void *qemu_blockalign0(BlockDriverState *bs, size_t size) | |
2687 | { | |
2688 | return memset(qemu_blockalign(bs, size), 0, size); | |
2689 | } | |
2690 | ||
2691 | void *qemu_try_blockalign(BlockDriverState *bs, size_t size) | |
2692 | { | |
2693 | size_t align = bdrv_opt_mem_align(bs); | |
2694 | ||
2695 | /* Ensure that NULL is never returned on success */ | |
2696 | assert(align > 0); | |
2697 | if (size == 0) { | |
2698 | size = align; | |
2699 | } | |
2700 | ||
2701 | return qemu_try_memalign(align, size); | |
2702 | } | |
2703 | ||
2704 | void *qemu_try_blockalign0(BlockDriverState *bs, size_t size) | |
2705 | { | |
2706 | void *mem = qemu_try_blockalign(bs, size); | |
2707 | ||
2708 | if (mem) { | |
2709 | memset(mem, 0, size); | |
2710 | } | |
2711 | ||
2712 | return mem; | |
2713 | } | |
2714 | ||
2715 | /* | |
2716 | * Check if all memory in this vector is sector aligned. | |
2717 | */ | |
2718 | bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) | |
2719 | { | |
2720 | int i; | |
4196d2f0 | 2721 | size_t alignment = bdrv_min_mem_align(bs); |
61007b31 SH |
2722 | |
2723 | for (i = 0; i < qiov->niov; i++) { | |
2724 | if ((uintptr_t) qiov->iov[i].iov_base % alignment) { | |
2725 | return false; | |
2726 | } | |
2727 | if (qiov->iov[i].iov_len % alignment) { | |
2728 | return false; | |
2729 | } | |
2730 | } | |
2731 | ||
2732 | return true; | |
2733 | } | |
2734 | ||
2735 | void bdrv_add_before_write_notifier(BlockDriverState *bs, | |
2736 | NotifierWithReturn *notifier) | |
2737 | { | |
2738 | notifier_with_return_list_add(&bs->before_write_notifiers, notifier); | |
2739 | } | |
2740 | ||
2741 | void bdrv_io_plug(BlockDriverState *bs) | |
2742 | { | |
2743 | BlockDriver *drv = bs->drv; | |
2744 | if (drv && drv->bdrv_io_plug) { | |
2745 | drv->bdrv_io_plug(bs); | |
2746 | } else if (bs->file) { | |
9a4f4c31 | 2747 | bdrv_io_plug(bs->file->bs); |
61007b31 SH |
2748 | } |
2749 | } | |
2750 | ||
2751 | void bdrv_io_unplug(BlockDriverState *bs) | |
2752 | { | |
2753 | BlockDriver *drv = bs->drv; | |
2754 | if (drv && drv->bdrv_io_unplug) { | |
2755 | drv->bdrv_io_unplug(bs); | |
2756 | } else if (bs->file) { | |
9a4f4c31 | 2757 | bdrv_io_unplug(bs->file->bs); |
61007b31 SH |
2758 | } |
2759 | } | |
2760 | ||
2761 | void bdrv_flush_io_queue(BlockDriverState *bs) | |
2762 | { | |
2763 | BlockDriver *drv = bs->drv; | |
2764 | if (drv && drv->bdrv_flush_io_queue) { | |
2765 | drv->bdrv_flush_io_queue(bs); | |
2766 | } else if (bs->file) { | |
9a4f4c31 | 2767 | bdrv_flush_io_queue(bs->file->bs); |
61007b31 | 2768 | } |
f406c03c | 2769 | bdrv_start_throttled_reqs(bs); |
61007b31 | 2770 | } |
51288d79 FZ |
2771 | |
2772 | void bdrv_drained_begin(BlockDriverState *bs) | |
2773 | { | |
2774 | if (!bs->quiesce_counter++) { | |
2775 | aio_disable_external(bdrv_get_aio_context(bs)); | |
2776 | } | |
2777 | bdrv_drain(bs); | |
2778 | } | |
2779 | ||
2780 | void bdrv_drained_end(BlockDriverState *bs) | |
2781 | { | |
2782 | assert(bs->quiesce_counter > 0); | |
2783 | if (--bs->quiesce_counter > 0) { | |
2784 | return; | |
2785 | } | |
2786 | aio_enable_external(bdrv_get_aio_context(bs)); | |
2787 | } |