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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" |
7719f3c9 | 28 | #include "block/aio-wait.h" |
61007b31 | 29 | #include "block/blockjob.h" |
f321dcb5 | 30 | #include "block/blockjob_int.h" |
61007b31 | 31 | #include "block/block_int.h" |
f348b6d1 | 32 | #include "qemu/cutils.h" |
da34e65c | 33 | #include "qapi/error.h" |
d49b6836 | 34 | #include "qemu/error-report.h" |
61007b31 SH |
35 | |
36 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
37 | ||
cb2e2878 EB |
38 | /* Maximum bounce buffer for copy-on-read and write zeroes, in bytes */ |
39 | #define MAX_BOUNCE_BUFFER (32768 << BDRV_SECTOR_BITS) | |
40 | ||
0f12264e KW |
41 | static AioWait drain_all_aio_wait; |
42 | ||
d05aa8bb | 43 | static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, |
f5a5ca79 | 44 | int64_t offset, int bytes, BdrvRequestFlags flags); |
61007b31 | 45 | |
6cd5c9d7 KW |
46 | void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore, |
47 | bool ignore_bds_parents) | |
61007b31 | 48 | { |
02d21300 | 49 | BdrvChild *c, *next; |
27ccdd52 | 50 | |
02d21300 | 51 | QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) { |
6cd5c9d7 | 52 | if (c == ignore || (ignore_bds_parents && c->role->parent_is_bds)) { |
0152bf40 KW |
53 | continue; |
54 | } | |
c2066af0 KW |
55 | if (c->role->drained_begin) { |
56 | c->role->drained_begin(c); | |
57 | } | |
ce0f1412 PB |
58 | } |
59 | } | |
61007b31 | 60 | |
6cd5c9d7 KW |
61 | void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore, |
62 | bool ignore_bds_parents) | |
ce0f1412 | 63 | { |
02d21300 | 64 | BdrvChild *c, *next; |
27ccdd52 | 65 | |
02d21300 | 66 | QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) { |
6cd5c9d7 | 67 | if (c == ignore || (ignore_bds_parents && c->role->parent_is_bds)) { |
0152bf40 KW |
68 | continue; |
69 | } | |
c2066af0 KW |
70 | if (c->role->drained_end) { |
71 | c->role->drained_end(c); | |
72 | } | |
27ccdd52 | 73 | } |
61007b31 SH |
74 | } |
75 | ||
6cd5c9d7 KW |
76 | static bool bdrv_parent_drained_poll(BlockDriverState *bs, BdrvChild *ignore, |
77 | bool ignore_bds_parents) | |
89bd0305 KW |
78 | { |
79 | BdrvChild *c, *next; | |
80 | bool busy = false; | |
81 | ||
82 | QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) { | |
6cd5c9d7 | 83 | if (c == ignore || (ignore_bds_parents && c->role->parent_is_bds)) { |
89bd0305 KW |
84 | continue; |
85 | } | |
86 | if (c->role->drained_poll) { | |
87 | busy |= c->role->drained_poll(c); | |
88 | } | |
89 | } | |
90 | ||
91 | return busy; | |
92 | } | |
93 | ||
d9e0dfa2 EB |
94 | static void bdrv_merge_limits(BlockLimits *dst, const BlockLimits *src) |
95 | { | |
96 | dst->opt_transfer = MAX(dst->opt_transfer, src->opt_transfer); | |
97 | dst->max_transfer = MIN_NON_ZERO(dst->max_transfer, src->max_transfer); | |
98 | dst->opt_mem_alignment = MAX(dst->opt_mem_alignment, | |
99 | src->opt_mem_alignment); | |
100 | dst->min_mem_alignment = MAX(dst->min_mem_alignment, | |
101 | src->min_mem_alignment); | |
102 | dst->max_iov = MIN_NON_ZERO(dst->max_iov, src->max_iov); | |
103 | } | |
104 | ||
61007b31 SH |
105 | void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) |
106 | { | |
107 | BlockDriver *drv = bs->drv; | |
108 | Error *local_err = NULL; | |
109 | ||
110 | memset(&bs->bl, 0, sizeof(bs->bl)); | |
111 | ||
112 | if (!drv) { | |
113 | return; | |
114 | } | |
115 | ||
79ba8c98 | 116 | /* Default alignment based on whether driver has byte interface */ |
e31f6864 EB |
117 | bs->bl.request_alignment = (drv->bdrv_co_preadv || |
118 | drv->bdrv_aio_preadv) ? 1 : 512; | |
79ba8c98 | 119 | |
61007b31 SH |
120 | /* Take some limits from the children as a default */ |
121 | if (bs->file) { | |
9a4f4c31 | 122 | bdrv_refresh_limits(bs->file->bs, &local_err); |
61007b31 SH |
123 | if (local_err) { |
124 | error_propagate(errp, local_err); | |
125 | return; | |
126 | } | |
d9e0dfa2 | 127 | bdrv_merge_limits(&bs->bl, &bs->file->bs->bl); |
61007b31 | 128 | } else { |
4196d2f0 | 129 | bs->bl.min_mem_alignment = 512; |
459b4e66 | 130 | bs->bl.opt_mem_alignment = getpagesize(); |
bd44feb7 SH |
131 | |
132 | /* Safe default since most protocols use readv()/writev()/etc */ | |
133 | bs->bl.max_iov = IOV_MAX; | |
61007b31 SH |
134 | } |
135 | ||
760e0063 KW |
136 | if (bs->backing) { |
137 | bdrv_refresh_limits(bs->backing->bs, &local_err); | |
61007b31 SH |
138 | if (local_err) { |
139 | error_propagate(errp, local_err); | |
140 | return; | |
141 | } | |
d9e0dfa2 | 142 | bdrv_merge_limits(&bs->bl, &bs->backing->bs->bl); |
61007b31 SH |
143 | } |
144 | ||
145 | /* Then let the driver override it */ | |
146 | if (drv->bdrv_refresh_limits) { | |
147 | drv->bdrv_refresh_limits(bs, errp); | |
148 | } | |
149 | } | |
150 | ||
151 | /** | |
152 | * The copy-on-read flag is actually a reference count so multiple users may | |
153 | * use the feature without worrying about clobbering its previous state. | |
154 | * Copy-on-read stays enabled until all users have called to disable it. | |
155 | */ | |
156 | void bdrv_enable_copy_on_read(BlockDriverState *bs) | |
157 | { | |
d3faa13e | 158 | atomic_inc(&bs->copy_on_read); |
61007b31 SH |
159 | } |
160 | ||
161 | void bdrv_disable_copy_on_read(BlockDriverState *bs) | |
162 | { | |
d3faa13e PB |
163 | int old = atomic_fetch_dec(&bs->copy_on_read); |
164 | assert(old >= 1); | |
61007b31 SH |
165 | } |
166 | ||
61124f03 PB |
167 | typedef struct { |
168 | Coroutine *co; | |
169 | BlockDriverState *bs; | |
170 | bool done; | |
481cad48 | 171 | bool begin; |
b0165585 | 172 | bool recursive; |
fe4f0614 | 173 | bool poll; |
0152bf40 | 174 | BdrvChild *parent; |
6cd5c9d7 | 175 | bool ignore_bds_parents; |
61124f03 PB |
176 | } BdrvCoDrainData; |
177 | ||
178 | static void coroutine_fn bdrv_drain_invoke_entry(void *opaque) | |
179 | { | |
180 | BdrvCoDrainData *data = opaque; | |
181 | BlockDriverState *bs = data->bs; | |
182 | ||
481cad48 | 183 | if (data->begin) { |
f8ea8dac | 184 | bs->drv->bdrv_co_drain_begin(bs); |
481cad48 MP |
185 | } else { |
186 | bs->drv->bdrv_co_drain_end(bs); | |
187 | } | |
61124f03 PB |
188 | |
189 | /* Set data->done before reading bs->wakeup. */ | |
190 | atomic_mb_set(&data->done, true); | |
0109e7e6 KW |
191 | bdrv_dec_in_flight(bs); |
192 | ||
193 | if (data->begin) { | |
194 | g_free(data); | |
195 | } | |
61124f03 PB |
196 | } |
197 | ||
db0289b9 | 198 | /* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */ |
7d40d9ef | 199 | static void bdrv_drain_invoke(BlockDriverState *bs, bool begin) |
61124f03 | 200 | { |
0109e7e6 | 201 | BdrvCoDrainData *data; |
61124f03 | 202 | |
f8ea8dac | 203 | if (!bs->drv || (begin && !bs->drv->bdrv_co_drain_begin) || |
481cad48 | 204 | (!begin && !bs->drv->bdrv_co_drain_end)) { |
61124f03 PB |
205 | return; |
206 | } | |
207 | ||
0109e7e6 KW |
208 | data = g_new(BdrvCoDrainData, 1); |
209 | *data = (BdrvCoDrainData) { | |
210 | .bs = bs, | |
211 | .done = false, | |
212 | .begin = begin | |
213 | }; | |
214 | ||
215 | /* Make sure the driver callback completes during the polling phase for | |
216 | * drain_begin. */ | |
217 | bdrv_inc_in_flight(bs); | |
218 | data->co = qemu_coroutine_create(bdrv_drain_invoke_entry, data); | |
219 | aio_co_schedule(bdrv_get_aio_context(bs), data->co); | |
220 | ||
221 | if (!begin) { | |
222 | BDRV_POLL_WHILE(bs, !data->done); | |
223 | g_free(data); | |
224 | } | |
61124f03 PB |
225 | } |
226 | ||
1cc8e54a | 227 | /* Returns true if BDRV_POLL_WHILE() should go into a blocking aio_poll() */ |
fe4f0614 | 228 | bool bdrv_drain_poll(BlockDriverState *bs, bool recursive, |
6cd5c9d7 | 229 | BdrvChild *ignore_parent, bool ignore_bds_parents) |
89bd0305 | 230 | { |
fe4f0614 KW |
231 | BdrvChild *child, *next; |
232 | ||
6cd5c9d7 | 233 | if (bdrv_parent_drained_poll(bs, ignore_parent, ignore_bds_parents)) { |
89bd0305 KW |
234 | return true; |
235 | } | |
236 | ||
fe4f0614 KW |
237 | if (atomic_read(&bs->in_flight)) { |
238 | return true; | |
239 | } | |
240 | ||
241 | if (recursive) { | |
6cd5c9d7 | 242 | assert(!ignore_bds_parents); |
fe4f0614 | 243 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
6cd5c9d7 | 244 | if (bdrv_drain_poll(child->bs, recursive, child, false)) { |
fe4f0614 KW |
245 | return true; |
246 | } | |
247 | } | |
248 | } | |
249 | ||
250 | return false; | |
89bd0305 KW |
251 | } |
252 | ||
fe4f0614 | 253 | static bool bdrv_drain_poll_top_level(BlockDriverState *bs, bool recursive, |
89bd0305 | 254 | BdrvChild *ignore_parent) |
1cc8e54a KW |
255 | { |
256 | /* Execute pending BHs first and check everything else only after the BHs | |
257 | * have executed. */ | |
258 | while (aio_poll(bs->aio_context, false)); | |
89bd0305 | 259 | |
6cd5c9d7 | 260 | return bdrv_drain_poll(bs, recursive, ignore_parent, false); |
1cc8e54a KW |
261 | } |
262 | ||
b0165585 | 263 | static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, |
6cd5c9d7 KW |
264 | BdrvChild *parent, bool ignore_bds_parents, |
265 | bool poll); | |
b0165585 | 266 | static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, |
6cd5c9d7 | 267 | BdrvChild *parent, bool ignore_bds_parents); |
0152bf40 | 268 | |
a77fd4bb FZ |
269 | static void bdrv_co_drain_bh_cb(void *opaque) |
270 | { | |
271 | BdrvCoDrainData *data = opaque; | |
272 | Coroutine *co = data->co; | |
99723548 | 273 | BlockDriverState *bs = data->bs; |
a77fd4bb | 274 | |
c8ca33d0 KW |
275 | if (bs) { |
276 | bdrv_dec_in_flight(bs); | |
277 | if (data->begin) { | |
6cd5c9d7 KW |
278 | bdrv_do_drained_begin(bs, data->recursive, data->parent, |
279 | data->ignore_bds_parents, data->poll); | |
c8ca33d0 | 280 | } else { |
6cd5c9d7 KW |
281 | bdrv_do_drained_end(bs, data->recursive, data->parent, |
282 | data->ignore_bds_parents); | |
c8ca33d0 | 283 | } |
481cad48 | 284 | } else { |
c8ca33d0 KW |
285 | assert(data->begin); |
286 | bdrv_drain_all_begin(); | |
481cad48 MP |
287 | } |
288 | ||
a77fd4bb | 289 | data->done = true; |
1919631e | 290 | aio_co_wake(co); |
a77fd4bb FZ |
291 | } |
292 | ||
481cad48 | 293 | static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, |
b0165585 | 294 | bool begin, bool recursive, |
6cd5c9d7 KW |
295 | BdrvChild *parent, |
296 | bool ignore_bds_parents, | |
297 | bool poll) | |
a77fd4bb FZ |
298 | { |
299 | BdrvCoDrainData data; | |
300 | ||
301 | /* Calling bdrv_drain() from a BH ensures the current coroutine yields and | |
c40a2545 | 302 | * other coroutines run if they were queued by aio_co_enter(). */ |
a77fd4bb FZ |
303 | |
304 | assert(qemu_in_coroutine()); | |
305 | data = (BdrvCoDrainData) { | |
306 | .co = qemu_coroutine_self(), | |
307 | .bs = bs, | |
308 | .done = false, | |
481cad48 | 309 | .begin = begin, |
b0165585 | 310 | .recursive = recursive, |
0152bf40 | 311 | .parent = parent, |
6cd5c9d7 | 312 | .ignore_bds_parents = ignore_bds_parents, |
fe4f0614 | 313 | .poll = poll, |
a77fd4bb | 314 | }; |
c8ca33d0 KW |
315 | if (bs) { |
316 | bdrv_inc_in_flight(bs); | |
317 | } | |
fffb6e12 PB |
318 | aio_bh_schedule_oneshot(bdrv_get_aio_context(bs), |
319 | bdrv_co_drain_bh_cb, &data); | |
a77fd4bb FZ |
320 | |
321 | qemu_coroutine_yield(); | |
322 | /* If we are resumed from some other event (such as an aio completion or a | |
323 | * timer callback), it is a bug in the caller that should be fixed. */ | |
324 | assert(data.done); | |
325 | } | |
326 | ||
dcf94a23 | 327 | void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, |
6cd5c9d7 | 328 | BdrvChild *parent, bool ignore_bds_parents) |
6820643f | 329 | { |
dcf94a23 | 330 | assert(!qemu_in_coroutine()); |
d42cf288 | 331 | |
60369b86 | 332 | /* Stop things in parent-to-child order */ |
414c2ec3 | 333 | if (atomic_fetch_inc(&bs->quiesce_counter) == 0) { |
6820643f | 334 | aio_disable_external(bdrv_get_aio_context(bs)); |
6820643f KW |
335 | } |
336 | ||
6cd5c9d7 | 337 | bdrv_parent_drained_begin(bs, parent, ignore_bds_parents); |
7d40d9ef | 338 | bdrv_drain_invoke(bs, true); |
dcf94a23 KW |
339 | } |
340 | ||
341 | static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, | |
6cd5c9d7 KW |
342 | BdrvChild *parent, bool ignore_bds_parents, |
343 | bool poll) | |
dcf94a23 KW |
344 | { |
345 | BdrvChild *child, *next; | |
346 | ||
347 | if (qemu_in_coroutine()) { | |
6cd5c9d7 KW |
348 | bdrv_co_yield_to_drain(bs, true, recursive, parent, ignore_bds_parents, |
349 | poll); | |
dcf94a23 KW |
350 | return; |
351 | } | |
352 | ||
6cd5c9d7 | 353 | bdrv_do_drained_begin_quiesce(bs, parent, ignore_bds_parents); |
d30b8e64 | 354 | |
b0165585 | 355 | if (recursive) { |
6cd5c9d7 | 356 | assert(!ignore_bds_parents); |
d736f119 | 357 | bs->recursive_quiesce_counter++; |
b0165585 | 358 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
6cd5c9d7 KW |
359 | bdrv_do_drained_begin(child->bs, true, child, ignore_bds_parents, |
360 | false); | |
b0165585 KW |
361 | } |
362 | } | |
fe4f0614 KW |
363 | |
364 | /* | |
365 | * Wait for drained requests to finish. | |
366 | * | |
367 | * Calling BDRV_POLL_WHILE() only once for the top-level node is okay: The | |
368 | * call is needed so things in this AioContext can make progress even | |
369 | * though we don't return to the main AioContext loop - this automatically | |
370 | * includes other nodes in the same AioContext and therefore all child | |
371 | * nodes. | |
372 | */ | |
373 | if (poll) { | |
6cd5c9d7 | 374 | assert(!ignore_bds_parents); |
fe4f0614 KW |
375 | BDRV_POLL_WHILE(bs, bdrv_drain_poll_top_level(bs, recursive, parent)); |
376 | } | |
6820643f KW |
377 | } |
378 | ||
0152bf40 KW |
379 | void bdrv_drained_begin(BlockDriverState *bs) |
380 | { | |
6cd5c9d7 | 381 | bdrv_do_drained_begin(bs, false, NULL, false, true); |
b0165585 KW |
382 | } |
383 | ||
384 | void bdrv_subtree_drained_begin(BlockDriverState *bs) | |
385 | { | |
6cd5c9d7 | 386 | bdrv_do_drained_begin(bs, true, NULL, false, true); |
0152bf40 KW |
387 | } |
388 | ||
6cd5c9d7 KW |
389 | static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, |
390 | BdrvChild *parent, bool ignore_bds_parents) | |
6820643f | 391 | { |
b0165585 | 392 | BdrvChild *child, *next; |
0f115168 KW |
393 | int old_quiesce_counter; |
394 | ||
481cad48 | 395 | if (qemu_in_coroutine()) { |
6cd5c9d7 KW |
396 | bdrv_co_yield_to_drain(bs, false, recursive, parent, ignore_bds_parents, |
397 | false); | |
481cad48 MP |
398 | return; |
399 | } | |
6820643f | 400 | assert(bs->quiesce_counter > 0); |
0f115168 | 401 | old_quiesce_counter = atomic_fetch_dec(&bs->quiesce_counter); |
6820643f | 402 | |
60369b86 | 403 | /* Re-enable things in child-to-parent order */ |
7d40d9ef | 404 | bdrv_drain_invoke(bs, false); |
6cd5c9d7 | 405 | bdrv_parent_drained_end(bs, parent, ignore_bds_parents); |
0f115168 | 406 | if (old_quiesce_counter == 1) { |
0f115168 KW |
407 | aio_enable_external(bdrv_get_aio_context(bs)); |
408 | } | |
b0165585 KW |
409 | |
410 | if (recursive) { | |
6cd5c9d7 | 411 | assert(!ignore_bds_parents); |
d736f119 | 412 | bs->recursive_quiesce_counter--; |
b0165585 | 413 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
6cd5c9d7 | 414 | bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents); |
b0165585 KW |
415 | } |
416 | } | |
6820643f KW |
417 | } |
418 | ||
0152bf40 KW |
419 | void bdrv_drained_end(BlockDriverState *bs) |
420 | { | |
6cd5c9d7 | 421 | bdrv_do_drained_end(bs, false, NULL, false); |
b0165585 KW |
422 | } |
423 | ||
424 | void bdrv_subtree_drained_end(BlockDriverState *bs) | |
425 | { | |
6cd5c9d7 | 426 | bdrv_do_drained_end(bs, true, NULL, false); |
0152bf40 KW |
427 | } |
428 | ||
d736f119 KW |
429 | void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent) |
430 | { | |
431 | int i; | |
432 | ||
433 | for (i = 0; i < new_parent->recursive_quiesce_counter; i++) { | |
6cd5c9d7 | 434 | bdrv_do_drained_begin(child->bs, true, child, false, true); |
d736f119 KW |
435 | } |
436 | } | |
437 | ||
438 | void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent) | |
439 | { | |
440 | int i; | |
441 | ||
442 | for (i = 0; i < old_parent->recursive_quiesce_counter; i++) { | |
6cd5c9d7 | 443 | bdrv_do_drained_end(child->bs, true, child, false); |
d736f119 KW |
444 | } |
445 | } | |
446 | ||
61007b31 | 447 | /* |
67da1dc5 FZ |
448 | * Wait for pending requests to complete on a single BlockDriverState subtree, |
449 | * and suspend block driver's internal I/O until next request arrives. | |
61007b31 | 450 | * |
61007b31 SH |
451 | * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState |
452 | * AioContext. | |
453 | */ | |
b6e84c97 | 454 | void coroutine_fn bdrv_co_drain(BlockDriverState *bs) |
61007b31 | 455 | { |
6820643f KW |
456 | assert(qemu_in_coroutine()); |
457 | bdrv_drained_begin(bs); | |
458 | bdrv_drained_end(bs); | |
b6e84c97 | 459 | } |
f406c03c | 460 | |
b6e84c97 PB |
461 | void bdrv_drain(BlockDriverState *bs) |
462 | { | |
6820643f KW |
463 | bdrv_drained_begin(bs); |
464 | bdrv_drained_end(bs); | |
61007b31 SH |
465 | } |
466 | ||
c13ad59f KW |
467 | static void bdrv_drain_assert_idle(BlockDriverState *bs) |
468 | { | |
469 | BdrvChild *child, *next; | |
470 | ||
471 | assert(atomic_read(&bs->in_flight) == 0); | |
472 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { | |
473 | bdrv_drain_assert_idle(child->bs); | |
474 | } | |
475 | } | |
476 | ||
0f12264e KW |
477 | unsigned int bdrv_drain_all_count = 0; |
478 | ||
479 | static bool bdrv_drain_all_poll(void) | |
480 | { | |
481 | BlockDriverState *bs = NULL; | |
482 | bool result = false; | |
483 | ||
484 | /* Execute pending BHs first (may modify the graph) and check everything | |
485 | * else only after the BHs have executed. */ | |
486 | while (aio_poll(qemu_get_aio_context(), false)); | |
487 | ||
488 | /* bdrv_drain_poll() can't make changes to the graph and we are holding the | |
489 | * main AioContext lock, so iterating bdrv_next_all_states() is safe. */ | |
490 | while ((bs = bdrv_next_all_states(bs))) { | |
491 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
492 | aio_context_acquire(aio_context); | |
493 | result |= bdrv_drain_poll(bs, false, NULL, true); | |
494 | aio_context_release(aio_context); | |
495 | } | |
496 | ||
497 | return result; | |
498 | } | |
499 | ||
61007b31 SH |
500 | /* |
501 | * Wait for pending requests to complete across all BlockDriverStates | |
502 | * | |
503 | * This function does not flush data to disk, use bdrv_flush_all() for that | |
504 | * after calling this function. | |
c0778f66 AG |
505 | * |
506 | * This pauses all block jobs and disables external clients. It must | |
507 | * be paired with bdrv_drain_all_end(). | |
508 | * | |
509 | * NOTE: no new block jobs or BlockDriverStates can be created between | |
510 | * the bdrv_drain_all_begin() and bdrv_drain_all_end() calls. | |
61007b31 | 511 | */ |
c0778f66 | 512 | void bdrv_drain_all_begin(void) |
61007b31 | 513 | { |
0f12264e | 514 | BlockDriverState *bs = NULL; |
61007b31 | 515 | |
c8ca33d0 | 516 | if (qemu_in_coroutine()) { |
0f12264e | 517 | bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true); |
c8ca33d0 KW |
518 | return; |
519 | } | |
520 | ||
0f12264e KW |
521 | /* AIO_WAIT_WHILE() with a NULL context can only be called from the main |
522 | * loop AioContext, so make sure we're in the main context. */ | |
9a7e86c8 | 523 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
0f12264e KW |
524 | assert(bdrv_drain_all_count < INT_MAX); |
525 | bdrv_drain_all_count++; | |
9a7e86c8 | 526 | |
0f12264e KW |
527 | /* Quiesce all nodes, without polling in-flight requests yet. The graph |
528 | * cannot change during this loop. */ | |
529 | while ((bs = bdrv_next_all_states(bs))) { | |
61007b31 SH |
530 | AioContext *aio_context = bdrv_get_aio_context(bs); |
531 | ||
532 | aio_context_acquire(aio_context); | |
0f12264e | 533 | bdrv_do_drained_begin(bs, false, NULL, true, false); |
61007b31 SH |
534 | aio_context_release(aio_context); |
535 | } | |
536 | ||
0f12264e KW |
537 | /* Now poll the in-flight requests */ |
538 | AIO_WAIT_WHILE(&drain_all_aio_wait, NULL, bdrv_drain_all_poll()); | |
539 | ||
540 | while ((bs = bdrv_next_all_states(bs))) { | |
c13ad59f | 541 | bdrv_drain_assert_idle(bs); |
61007b31 | 542 | } |
c0778f66 AG |
543 | } |
544 | ||
545 | void bdrv_drain_all_end(void) | |
546 | { | |
0f12264e | 547 | BlockDriverState *bs = NULL; |
c0778f66 | 548 | |
0f12264e | 549 | while ((bs = bdrv_next_all_states(bs))) { |
61007b31 SH |
550 | AioContext *aio_context = bdrv_get_aio_context(bs); |
551 | ||
552 | aio_context_acquire(aio_context); | |
0f12264e | 553 | bdrv_do_drained_end(bs, false, NULL, true); |
61007b31 SH |
554 | aio_context_release(aio_context); |
555 | } | |
0f12264e KW |
556 | |
557 | assert(bdrv_drain_all_count > 0); | |
558 | bdrv_drain_all_count--; | |
61007b31 SH |
559 | } |
560 | ||
c0778f66 AG |
561 | void bdrv_drain_all(void) |
562 | { | |
563 | bdrv_drain_all_begin(); | |
564 | bdrv_drain_all_end(); | |
565 | } | |
566 | ||
61007b31 SH |
567 | /** |
568 | * Remove an active request from the tracked requests list | |
569 | * | |
570 | * This function should be called when a tracked request is completing. | |
571 | */ | |
572 | static void tracked_request_end(BdrvTrackedRequest *req) | |
573 | { | |
574 | if (req->serialising) { | |
20fc71b2 | 575 | atomic_dec(&req->bs->serialising_in_flight); |
61007b31 SH |
576 | } |
577 | ||
3783fa3d | 578 | qemu_co_mutex_lock(&req->bs->reqs_lock); |
61007b31 SH |
579 | QLIST_REMOVE(req, list); |
580 | qemu_co_queue_restart_all(&req->wait_queue); | |
3783fa3d | 581 | qemu_co_mutex_unlock(&req->bs->reqs_lock); |
61007b31 SH |
582 | } |
583 | ||
584 | /** | |
585 | * Add an active request to the tracked requests list | |
586 | */ | |
587 | static void tracked_request_begin(BdrvTrackedRequest *req, | |
588 | BlockDriverState *bs, | |
589 | int64_t offset, | |
ebde595c FZ |
590 | unsigned int bytes, |
591 | enum BdrvTrackedRequestType type) | |
61007b31 SH |
592 | { |
593 | *req = (BdrvTrackedRequest){ | |
594 | .bs = bs, | |
595 | .offset = offset, | |
596 | .bytes = bytes, | |
ebde595c | 597 | .type = type, |
61007b31 SH |
598 | .co = qemu_coroutine_self(), |
599 | .serialising = false, | |
600 | .overlap_offset = offset, | |
601 | .overlap_bytes = bytes, | |
602 | }; | |
603 | ||
604 | qemu_co_queue_init(&req->wait_queue); | |
605 | ||
3783fa3d | 606 | qemu_co_mutex_lock(&bs->reqs_lock); |
61007b31 | 607 | QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); |
3783fa3d | 608 | qemu_co_mutex_unlock(&bs->reqs_lock); |
61007b31 SH |
609 | } |
610 | ||
611 | static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) | |
612 | { | |
613 | int64_t overlap_offset = req->offset & ~(align - 1); | |
614 | unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align) | |
615 | - overlap_offset; | |
616 | ||
617 | if (!req->serialising) { | |
20fc71b2 | 618 | atomic_inc(&req->bs->serialising_in_flight); |
61007b31 SH |
619 | req->serialising = true; |
620 | } | |
621 | ||
622 | req->overlap_offset = MIN(req->overlap_offset, overlap_offset); | |
623 | req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); | |
624 | } | |
625 | ||
244483e6 KW |
626 | /** |
627 | * Round a region to cluster boundaries | |
628 | */ | |
629 | void bdrv_round_to_clusters(BlockDriverState *bs, | |
7cfd5275 | 630 | int64_t offset, int64_t bytes, |
244483e6 | 631 | int64_t *cluster_offset, |
7cfd5275 | 632 | int64_t *cluster_bytes) |
244483e6 KW |
633 | { |
634 | BlockDriverInfo bdi; | |
635 | ||
636 | if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { | |
637 | *cluster_offset = offset; | |
638 | *cluster_bytes = bytes; | |
639 | } else { | |
640 | int64_t c = bdi.cluster_size; | |
641 | *cluster_offset = QEMU_ALIGN_DOWN(offset, c); | |
642 | *cluster_bytes = QEMU_ALIGN_UP(offset - *cluster_offset + bytes, c); | |
643 | } | |
644 | } | |
645 | ||
61007b31 SH |
646 | static int bdrv_get_cluster_size(BlockDriverState *bs) |
647 | { | |
648 | BlockDriverInfo bdi; | |
649 | int ret; | |
650 | ||
651 | ret = bdrv_get_info(bs, &bdi); | |
652 | if (ret < 0 || bdi.cluster_size == 0) { | |
a5b8dd2c | 653 | return bs->bl.request_alignment; |
61007b31 SH |
654 | } else { |
655 | return bdi.cluster_size; | |
656 | } | |
657 | } | |
658 | ||
659 | static bool tracked_request_overlaps(BdrvTrackedRequest *req, | |
660 | int64_t offset, unsigned int bytes) | |
661 | { | |
662 | /* aaaa bbbb */ | |
663 | if (offset >= req->overlap_offset + req->overlap_bytes) { | |
664 | return false; | |
665 | } | |
666 | /* bbbb aaaa */ | |
667 | if (req->overlap_offset >= offset + bytes) { | |
668 | return false; | |
669 | } | |
670 | return true; | |
671 | } | |
672 | ||
99723548 PB |
673 | void bdrv_inc_in_flight(BlockDriverState *bs) |
674 | { | |
675 | atomic_inc(&bs->in_flight); | |
676 | } | |
677 | ||
c9d1a561 PB |
678 | void bdrv_wakeup(BlockDriverState *bs) |
679 | { | |
7719f3c9 | 680 | aio_wait_kick(bdrv_get_aio_wait(bs)); |
0f12264e | 681 | aio_wait_kick(&drain_all_aio_wait); |
c9d1a561 PB |
682 | } |
683 | ||
99723548 PB |
684 | void bdrv_dec_in_flight(BlockDriverState *bs) |
685 | { | |
686 | atomic_dec(&bs->in_flight); | |
c9d1a561 | 687 | bdrv_wakeup(bs); |
99723548 PB |
688 | } |
689 | ||
61007b31 SH |
690 | static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) |
691 | { | |
692 | BlockDriverState *bs = self->bs; | |
693 | BdrvTrackedRequest *req; | |
694 | bool retry; | |
695 | bool waited = false; | |
696 | ||
20fc71b2 | 697 | if (!atomic_read(&bs->serialising_in_flight)) { |
61007b31 SH |
698 | return false; |
699 | } | |
700 | ||
701 | do { | |
702 | retry = false; | |
3783fa3d | 703 | qemu_co_mutex_lock(&bs->reqs_lock); |
61007b31 SH |
704 | QLIST_FOREACH(req, &bs->tracked_requests, list) { |
705 | if (req == self || (!req->serialising && !self->serialising)) { | |
706 | continue; | |
707 | } | |
708 | if (tracked_request_overlaps(req, self->overlap_offset, | |
709 | self->overlap_bytes)) | |
710 | { | |
711 | /* Hitting this means there was a reentrant request, for | |
712 | * example, a block driver issuing nested requests. This must | |
713 | * never happen since it means deadlock. | |
714 | */ | |
715 | assert(qemu_coroutine_self() != req->co); | |
716 | ||
717 | /* If the request is already (indirectly) waiting for us, or | |
718 | * will wait for us as soon as it wakes up, then just go on | |
719 | * (instead of producing a deadlock in the former case). */ | |
720 | if (!req->waiting_for) { | |
721 | self->waiting_for = req; | |
3783fa3d | 722 | qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock); |
61007b31 SH |
723 | self->waiting_for = NULL; |
724 | retry = true; | |
725 | waited = true; | |
726 | break; | |
727 | } | |
728 | } | |
729 | } | |
3783fa3d | 730 | qemu_co_mutex_unlock(&bs->reqs_lock); |
61007b31 SH |
731 | } while (retry); |
732 | ||
733 | return waited; | |
734 | } | |
735 | ||
736 | static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, | |
737 | size_t size) | |
738 | { | |
739 | if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) { | |
740 | return -EIO; | |
741 | } | |
742 | ||
743 | if (!bdrv_is_inserted(bs)) { | |
744 | return -ENOMEDIUM; | |
745 | } | |
746 | ||
747 | if (offset < 0) { | |
748 | return -EIO; | |
749 | } | |
750 | ||
751 | return 0; | |
752 | } | |
753 | ||
61007b31 | 754 | typedef struct RwCo { |
e293b7a3 | 755 | BdrvChild *child; |
61007b31 SH |
756 | int64_t offset; |
757 | QEMUIOVector *qiov; | |
758 | bool is_write; | |
759 | int ret; | |
760 | BdrvRequestFlags flags; | |
761 | } RwCo; | |
762 | ||
763 | static void coroutine_fn bdrv_rw_co_entry(void *opaque) | |
764 | { | |
765 | RwCo *rwco = opaque; | |
766 | ||
767 | if (!rwco->is_write) { | |
a03ef88f | 768 | rwco->ret = bdrv_co_preadv(rwco->child, rwco->offset, |
cab3a356 KW |
769 | rwco->qiov->size, rwco->qiov, |
770 | rwco->flags); | |
61007b31 | 771 | } else { |
a03ef88f | 772 | rwco->ret = bdrv_co_pwritev(rwco->child, rwco->offset, |
cab3a356 KW |
773 | rwco->qiov->size, rwco->qiov, |
774 | rwco->flags); | |
61007b31 SH |
775 | } |
776 | } | |
777 | ||
778 | /* | |
779 | * Process a vectored synchronous request using coroutines | |
780 | */ | |
e293b7a3 | 781 | static int bdrv_prwv_co(BdrvChild *child, int64_t offset, |
61007b31 SH |
782 | QEMUIOVector *qiov, bool is_write, |
783 | BdrvRequestFlags flags) | |
784 | { | |
785 | Coroutine *co; | |
786 | RwCo rwco = { | |
e293b7a3 | 787 | .child = child, |
61007b31 SH |
788 | .offset = offset, |
789 | .qiov = qiov, | |
790 | .is_write = is_write, | |
791 | .ret = NOT_DONE, | |
792 | .flags = flags, | |
793 | }; | |
794 | ||
61007b31 SH |
795 | if (qemu_in_coroutine()) { |
796 | /* Fast-path if already in coroutine context */ | |
797 | bdrv_rw_co_entry(&rwco); | |
798 | } else { | |
0b8b8753 | 799 | co = qemu_coroutine_create(bdrv_rw_co_entry, &rwco); |
e92f0e19 | 800 | bdrv_coroutine_enter(child->bs, co); |
88b062c2 | 801 | BDRV_POLL_WHILE(child->bs, rwco.ret == NOT_DONE); |
61007b31 SH |
802 | } |
803 | return rwco.ret; | |
804 | } | |
805 | ||
806 | /* | |
807 | * Process a synchronous request using coroutines | |
808 | */ | |
e293b7a3 | 809 | static int bdrv_rw_co(BdrvChild *child, int64_t sector_num, uint8_t *buf, |
61007b31 SH |
810 | int nb_sectors, bool is_write, BdrvRequestFlags flags) |
811 | { | |
812 | QEMUIOVector qiov; | |
813 | struct iovec iov = { | |
814 | .iov_base = (void *)buf, | |
815 | .iov_len = nb_sectors * BDRV_SECTOR_SIZE, | |
816 | }; | |
817 | ||
818 | if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { | |
819 | return -EINVAL; | |
820 | } | |
821 | ||
822 | qemu_iovec_init_external(&qiov, &iov, 1); | |
e293b7a3 | 823 | return bdrv_prwv_co(child, sector_num << BDRV_SECTOR_BITS, |
61007b31 SH |
824 | &qiov, is_write, flags); |
825 | } | |
826 | ||
827 | /* return < 0 if error. See bdrv_write() for the return codes */ | |
fbcbbf4e | 828 | int bdrv_read(BdrvChild *child, int64_t sector_num, |
61007b31 SH |
829 | uint8_t *buf, int nb_sectors) |
830 | { | |
e293b7a3 | 831 | return bdrv_rw_co(child, sector_num, buf, nb_sectors, false, 0); |
61007b31 SH |
832 | } |
833 | ||
61007b31 SH |
834 | /* Return < 0 if error. Important errors are: |
835 | -EIO generic I/O error (may happen for all errors) | |
836 | -ENOMEDIUM No media inserted. | |
837 | -EINVAL Invalid sector number or nb_sectors | |
838 | -EACCES Trying to write a read-only device | |
839 | */ | |
18d51c4b | 840 | int bdrv_write(BdrvChild *child, int64_t sector_num, |
61007b31 SH |
841 | const uint8_t *buf, int nb_sectors) |
842 | { | |
e293b7a3 | 843 | return bdrv_rw_co(child, sector_num, (uint8_t *)buf, nb_sectors, true, 0); |
61007b31 SH |
844 | } |
845 | ||
720ff280 | 846 | int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, |
f5a5ca79 | 847 | int bytes, BdrvRequestFlags flags) |
61007b31 | 848 | { |
74021bc4 EB |
849 | QEMUIOVector qiov; |
850 | struct iovec iov = { | |
851 | .iov_base = NULL, | |
f5a5ca79 | 852 | .iov_len = bytes, |
74021bc4 EB |
853 | }; |
854 | ||
855 | qemu_iovec_init_external(&qiov, &iov, 1); | |
e293b7a3 | 856 | return bdrv_prwv_co(child, offset, &qiov, true, |
74021bc4 | 857 | BDRV_REQ_ZERO_WRITE | flags); |
61007b31 SH |
858 | } |
859 | ||
860 | /* | |
74021bc4 | 861 | * Completely zero out a block device with the help of bdrv_pwrite_zeroes. |
61007b31 SH |
862 | * The operation is sped up by checking the block status and only writing |
863 | * zeroes to the device if they currently do not return zeroes. Optional | |
74021bc4 | 864 | * flags are passed through to bdrv_pwrite_zeroes (e.g. BDRV_REQ_MAY_UNMAP, |
465fe887 | 865 | * BDRV_REQ_FUA). |
61007b31 SH |
866 | * |
867 | * Returns < 0 on error, 0 on success. For error codes see bdrv_write(). | |
868 | */ | |
720ff280 | 869 | int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags) |
61007b31 | 870 | { |
237d78f8 EB |
871 | int ret; |
872 | int64_t target_size, bytes, offset = 0; | |
720ff280 | 873 | BlockDriverState *bs = child->bs; |
61007b31 | 874 | |
7286d610 EB |
875 | target_size = bdrv_getlength(bs); |
876 | if (target_size < 0) { | |
877 | return target_size; | |
61007b31 SH |
878 | } |
879 | ||
880 | for (;;) { | |
7286d610 EB |
881 | bytes = MIN(target_size - offset, BDRV_REQUEST_MAX_BYTES); |
882 | if (bytes <= 0) { | |
61007b31 SH |
883 | return 0; |
884 | } | |
237d78f8 | 885 | ret = bdrv_block_status(bs, offset, bytes, &bytes, NULL, NULL); |
61007b31 | 886 | if (ret < 0) { |
7286d610 EB |
887 | error_report("error getting block status at offset %" PRId64 ": %s", |
888 | offset, strerror(-ret)); | |
61007b31 SH |
889 | return ret; |
890 | } | |
891 | if (ret & BDRV_BLOCK_ZERO) { | |
237d78f8 | 892 | offset += bytes; |
61007b31 SH |
893 | continue; |
894 | } | |
237d78f8 | 895 | ret = bdrv_pwrite_zeroes(child, offset, bytes, flags); |
61007b31 | 896 | if (ret < 0) { |
7286d610 EB |
897 | error_report("error writing zeroes at offset %" PRId64 ": %s", |
898 | offset, strerror(-ret)); | |
61007b31 SH |
899 | return ret; |
900 | } | |
237d78f8 | 901 | offset += bytes; |
61007b31 SH |
902 | } |
903 | } | |
904 | ||
cf2ab8fc | 905 | int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov) |
f1e84741 KW |
906 | { |
907 | int ret; | |
908 | ||
e293b7a3 | 909 | ret = bdrv_prwv_co(child, offset, qiov, false, 0); |
f1e84741 KW |
910 | if (ret < 0) { |
911 | return ret; | |
912 | } | |
913 | ||
914 | return qiov->size; | |
915 | } | |
916 | ||
cf2ab8fc | 917 | int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes) |
61007b31 SH |
918 | { |
919 | QEMUIOVector qiov; | |
920 | struct iovec iov = { | |
921 | .iov_base = (void *)buf, | |
922 | .iov_len = bytes, | |
923 | }; | |
61007b31 SH |
924 | |
925 | if (bytes < 0) { | |
926 | return -EINVAL; | |
927 | } | |
928 | ||
929 | qemu_iovec_init_external(&qiov, &iov, 1); | |
cf2ab8fc | 930 | return bdrv_preadv(child, offset, &qiov); |
61007b31 SH |
931 | } |
932 | ||
d9ca2ea2 | 933 | int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov) |
61007b31 SH |
934 | { |
935 | int ret; | |
936 | ||
e293b7a3 | 937 | ret = bdrv_prwv_co(child, offset, qiov, true, 0); |
61007b31 SH |
938 | if (ret < 0) { |
939 | return ret; | |
940 | } | |
941 | ||
942 | return qiov->size; | |
943 | } | |
944 | ||
d9ca2ea2 | 945 | int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes) |
61007b31 SH |
946 | { |
947 | QEMUIOVector qiov; | |
948 | struct iovec iov = { | |
949 | .iov_base = (void *) buf, | |
950 | .iov_len = bytes, | |
951 | }; | |
952 | ||
953 | if (bytes < 0) { | |
954 | return -EINVAL; | |
955 | } | |
956 | ||
957 | qemu_iovec_init_external(&qiov, &iov, 1); | |
d9ca2ea2 | 958 | return bdrv_pwritev(child, offset, &qiov); |
61007b31 SH |
959 | } |
960 | ||
961 | /* | |
962 | * Writes to the file and ensures that no writes are reordered across this | |
963 | * request (acts as a barrier) | |
964 | * | |
965 | * Returns 0 on success, -errno in error cases. | |
966 | */ | |
d9ca2ea2 KW |
967 | int bdrv_pwrite_sync(BdrvChild *child, int64_t offset, |
968 | const void *buf, int count) | |
61007b31 SH |
969 | { |
970 | int ret; | |
971 | ||
d9ca2ea2 | 972 | ret = bdrv_pwrite(child, offset, buf, count); |
61007b31 SH |
973 | if (ret < 0) { |
974 | return ret; | |
975 | } | |
976 | ||
d9ca2ea2 | 977 | ret = bdrv_flush(child->bs); |
855a6a93 KW |
978 | if (ret < 0) { |
979 | return ret; | |
61007b31 SH |
980 | } |
981 | ||
982 | return 0; | |
983 | } | |
984 | ||
08844473 KW |
985 | typedef struct CoroutineIOCompletion { |
986 | Coroutine *coroutine; | |
987 | int ret; | |
988 | } CoroutineIOCompletion; | |
989 | ||
990 | static void bdrv_co_io_em_complete(void *opaque, int ret) | |
991 | { | |
992 | CoroutineIOCompletion *co = opaque; | |
993 | ||
994 | co->ret = ret; | |
b9e413dd | 995 | aio_co_wake(co->coroutine); |
08844473 KW |
996 | } |
997 | ||
166fe960 KW |
998 | static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs, |
999 | uint64_t offset, uint64_t bytes, | |
1000 | QEMUIOVector *qiov, int flags) | |
1001 | { | |
1002 | BlockDriver *drv = bs->drv; | |
3fb06697 KW |
1003 | int64_t sector_num; |
1004 | unsigned int nb_sectors; | |
1005 | ||
fa166538 EB |
1006 | assert(!(flags & ~BDRV_REQ_MASK)); |
1007 | ||
d470ad42 HR |
1008 | if (!drv) { |
1009 | return -ENOMEDIUM; | |
1010 | } | |
1011 | ||
3fb06697 KW |
1012 | if (drv->bdrv_co_preadv) { |
1013 | return drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags); | |
1014 | } | |
1015 | ||
edfab6a0 | 1016 | if (drv->bdrv_aio_preadv) { |
08844473 KW |
1017 | BlockAIOCB *acb; |
1018 | CoroutineIOCompletion co = { | |
1019 | .coroutine = qemu_coroutine_self(), | |
1020 | }; | |
1021 | ||
edfab6a0 EB |
1022 | acb = drv->bdrv_aio_preadv(bs, offset, bytes, qiov, flags, |
1023 | bdrv_co_io_em_complete, &co); | |
08844473 KW |
1024 | if (acb == NULL) { |
1025 | return -EIO; | |
1026 | } else { | |
1027 | qemu_coroutine_yield(); | |
1028 | return co.ret; | |
1029 | } | |
1030 | } | |
edfab6a0 EB |
1031 | |
1032 | sector_num = offset >> BDRV_SECTOR_BITS; | |
1033 | nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
1034 | ||
1035 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1036 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1037 | assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS); | |
1038 | assert(drv->bdrv_co_readv); | |
1039 | ||
1040 | return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); | |
166fe960 KW |
1041 | } |
1042 | ||
78a07294 KW |
1043 | static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs, |
1044 | uint64_t offset, uint64_t bytes, | |
1045 | QEMUIOVector *qiov, int flags) | |
1046 | { | |
1047 | BlockDriver *drv = bs->drv; | |
3fb06697 KW |
1048 | int64_t sector_num; |
1049 | unsigned int nb_sectors; | |
78a07294 KW |
1050 | int ret; |
1051 | ||
fa166538 EB |
1052 | assert(!(flags & ~BDRV_REQ_MASK)); |
1053 | ||
d470ad42 HR |
1054 | if (!drv) { |
1055 | return -ENOMEDIUM; | |
1056 | } | |
1057 | ||
3fb06697 | 1058 | if (drv->bdrv_co_pwritev) { |
515c2f43 KW |
1059 | ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov, |
1060 | flags & bs->supported_write_flags); | |
1061 | flags &= ~bs->supported_write_flags; | |
3fb06697 KW |
1062 | goto emulate_flags; |
1063 | } | |
1064 | ||
edfab6a0 | 1065 | if (drv->bdrv_aio_pwritev) { |
08844473 KW |
1066 | BlockAIOCB *acb; |
1067 | CoroutineIOCompletion co = { | |
1068 | .coroutine = qemu_coroutine_self(), | |
1069 | }; | |
1070 | ||
edfab6a0 EB |
1071 | acb = drv->bdrv_aio_pwritev(bs, offset, bytes, qiov, |
1072 | flags & bs->supported_write_flags, | |
1073 | bdrv_co_io_em_complete, &co); | |
1074 | flags &= ~bs->supported_write_flags; | |
08844473 | 1075 | if (acb == NULL) { |
3fb06697 | 1076 | ret = -EIO; |
08844473 KW |
1077 | } else { |
1078 | qemu_coroutine_yield(); | |
3fb06697 | 1079 | ret = co.ret; |
08844473 | 1080 | } |
edfab6a0 EB |
1081 | goto emulate_flags; |
1082 | } | |
1083 | ||
1084 | sector_num = offset >> BDRV_SECTOR_BITS; | |
1085 | nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
1086 | ||
1087 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1088 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
1089 | assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS); | |
1090 | ||
e18a58b4 EB |
1091 | assert(drv->bdrv_co_writev); |
1092 | ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov, | |
1093 | flags & bs->supported_write_flags); | |
1094 | flags &= ~bs->supported_write_flags; | |
78a07294 | 1095 | |
3fb06697 | 1096 | emulate_flags: |
4df863f3 | 1097 | if (ret == 0 && (flags & BDRV_REQ_FUA)) { |
78a07294 KW |
1098 | ret = bdrv_co_flush(bs); |
1099 | } | |
1100 | ||
1101 | return ret; | |
1102 | } | |
1103 | ||
29a298af PB |
1104 | static int coroutine_fn |
1105 | bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset, | |
1106 | uint64_t bytes, QEMUIOVector *qiov) | |
1107 | { | |
1108 | BlockDriver *drv = bs->drv; | |
1109 | ||
d470ad42 HR |
1110 | if (!drv) { |
1111 | return -ENOMEDIUM; | |
1112 | } | |
1113 | ||
29a298af PB |
1114 | if (!drv->bdrv_co_pwritev_compressed) { |
1115 | return -ENOTSUP; | |
1116 | } | |
1117 | ||
29a298af PB |
1118 | return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov); |
1119 | } | |
1120 | ||
85c97ca7 | 1121 | static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, |
244483e6 | 1122 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov) |
61007b31 | 1123 | { |
85c97ca7 KW |
1124 | BlockDriverState *bs = child->bs; |
1125 | ||
61007b31 SH |
1126 | /* Perform I/O through a temporary buffer so that users who scribble over |
1127 | * their read buffer while the operation is in progress do not end up | |
1128 | * modifying the image file. This is critical for zero-copy guest I/O | |
1129 | * where anything might happen inside guest memory. | |
1130 | */ | |
1131 | void *bounce_buffer; | |
1132 | ||
1133 | BlockDriver *drv = bs->drv; | |
1134 | struct iovec iov; | |
cb2e2878 | 1135 | QEMUIOVector local_qiov; |
244483e6 | 1136 | int64_t cluster_offset; |
7cfd5275 | 1137 | int64_t cluster_bytes; |
61007b31 SH |
1138 | size_t skip_bytes; |
1139 | int ret; | |
cb2e2878 EB |
1140 | int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, |
1141 | BDRV_REQUEST_MAX_BYTES); | |
1142 | unsigned int progress = 0; | |
61007b31 | 1143 | |
d470ad42 HR |
1144 | if (!drv) { |
1145 | return -ENOMEDIUM; | |
1146 | } | |
1147 | ||
1bf03e66 KW |
1148 | /* FIXME We cannot require callers to have write permissions when all they |
1149 | * are doing is a read request. If we did things right, write permissions | |
1150 | * would be obtained anyway, but internally by the copy-on-read code. As | |
765d9df9 | 1151 | * long as it is implemented here rather than in a separate filter driver, |
1bf03e66 KW |
1152 | * the copy-on-read code doesn't have its own BdrvChild, however, for which |
1153 | * it could request permissions. Therefore we have to bypass the permission | |
1154 | * system for the moment. */ | |
1155 | // assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE)); | |
afa4b293 | 1156 | |
61007b31 | 1157 | /* Cover entire cluster so no additional backing file I/O is required when |
cb2e2878 EB |
1158 | * allocating cluster in the image file. Note that this value may exceed |
1159 | * BDRV_REQUEST_MAX_BYTES (even when the original read did not), which | |
1160 | * is one reason we loop rather than doing it all at once. | |
61007b31 | 1161 | */ |
244483e6 | 1162 | bdrv_round_to_clusters(bs, offset, bytes, &cluster_offset, &cluster_bytes); |
cb2e2878 | 1163 | skip_bytes = offset - cluster_offset; |
61007b31 | 1164 | |
244483e6 KW |
1165 | trace_bdrv_co_do_copy_on_readv(bs, offset, bytes, |
1166 | cluster_offset, cluster_bytes); | |
61007b31 | 1167 | |
cb2e2878 EB |
1168 | bounce_buffer = qemu_try_blockalign(bs, |
1169 | MIN(MIN(max_transfer, cluster_bytes), | |
1170 | MAX_BOUNCE_BUFFER)); | |
61007b31 SH |
1171 | if (bounce_buffer == NULL) { |
1172 | ret = -ENOMEM; | |
1173 | goto err; | |
1174 | } | |
1175 | ||
cb2e2878 EB |
1176 | while (cluster_bytes) { |
1177 | int64_t pnum; | |
61007b31 | 1178 | |
cb2e2878 EB |
1179 | ret = bdrv_is_allocated(bs, cluster_offset, |
1180 | MIN(cluster_bytes, max_transfer), &pnum); | |
1181 | if (ret < 0) { | |
1182 | /* Safe to treat errors in querying allocation as if | |
1183 | * unallocated; we'll probably fail again soon on the | |
1184 | * read, but at least that will set a decent errno. | |
1185 | */ | |
1186 | pnum = MIN(cluster_bytes, max_transfer); | |
1187 | } | |
61007b31 | 1188 | |
cb2e2878 | 1189 | assert(skip_bytes < pnum); |
61007b31 | 1190 | |
cb2e2878 EB |
1191 | if (ret <= 0) { |
1192 | /* Must copy-on-read; use the bounce buffer */ | |
1193 | iov.iov_base = bounce_buffer; | |
1194 | iov.iov_len = pnum = MIN(pnum, MAX_BOUNCE_BUFFER); | |
1195 | qemu_iovec_init_external(&local_qiov, &iov, 1); | |
61007b31 | 1196 | |
cb2e2878 EB |
1197 | ret = bdrv_driver_preadv(bs, cluster_offset, pnum, |
1198 | &local_qiov, 0); | |
1199 | if (ret < 0) { | |
1200 | goto err; | |
1201 | } | |
1202 | ||
1203 | bdrv_debug_event(bs, BLKDBG_COR_WRITE); | |
1204 | if (drv->bdrv_co_pwrite_zeroes && | |
1205 | buffer_is_zero(bounce_buffer, pnum)) { | |
1206 | /* FIXME: Should we (perhaps conditionally) be setting | |
1207 | * BDRV_REQ_MAY_UNMAP, if it will allow for a sparser copy | |
1208 | * that still correctly reads as zero? */ | |
7adcf59f HR |
1209 | ret = bdrv_co_do_pwrite_zeroes(bs, cluster_offset, pnum, |
1210 | BDRV_REQ_WRITE_UNCHANGED); | |
cb2e2878 EB |
1211 | } else { |
1212 | /* This does not change the data on the disk, it is not | |
1213 | * necessary to flush even in cache=writethrough mode. | |
1214 | */ | |
1215 | ret = bdrv_driver_pwritev(bs, cluster_offset, pnum, | |
7adcf59f HR |
1216 | &local_qiov, |
1217 | BDRV_REQ_WRITE_UNCHANGED); | |
cb2e2878 EB |
1218 | } |
1219 | ||
1220 | if (ret < 0) { | |
1221 | /* It might be okay to ignore write errors for guest | |
1222 | * requests. If this is a deliberate copy-on-read | |
1223 | * then we don't want to ignore the error. Simply | |
1224 | * report it in all cases. | |
1225 | */ | |
1226 | goto err; | |
1227 | } | |
1228 | ||
1229 | qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes, | |
1230 | pnum - skip_bytes); | |
1231 | } else { | |
1232 | /* Read directly into the destination */ | |
1233 | qemu_iovec_init(&local_qiov, qiov->niov); | |
1234 | qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes); | |
1235 | ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size, | |
1236 | &local_qiov, 0); | |
1237 | qemu_iovec_destroy(&local_qiov); | |
1238 | if (ret < 0) { | |
1239 | goto err; | |
1240 | } | |
1241 | } | |
1242 | ||
1243 | cluster_offset += pnum; | |
1244 | cluster_bytes -= pnum; | |
1245 | progress += pnum - skip_bytes; | |
1246 | skip_bytes = 0; | |
1247 | } | |
1248 | ret = 0; | |
61007b31 SH |
1249 | |
1250 | err: | |
1251 | qemu_vfree(bounce_buffer); | |
1252 | return ret; | |
1253 | } | |
1254 | ||
1255 | /* | |
1256 | * Forwards an already correctly aligned request to the BlockDriver. This | |
1a62d0ac EB |
1257 | * handles copy on read, zeroing after EOF, and fragmentation of large |
1258 | * reads; any other features must be implemented by the caller. | |
61007b31 | 1259 | */ |
85c97ca7 | 1260 | static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, |
61007b31 SH |
1261 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, |
1262 | int64_t align, QEMUIOVector *qiov, int flags) | |
1263 | { | |
85c97ca7 | 1264 | BlockDriverState *bs = child->bs; |
c9d20029 | 1265 | int64_t total_bytes, max_bytes; |
1a62d0ac EB |
1266 | int ret = 0; |
1267 | uint64_t bytes_remaining = bytes; | |
1268 | int max_transfer; | |
61007b31 | 1269 | |
49c07526 KW |
1270 | assert(is_power_of_2(align)); |
1271 | assert((offset & (align - 1)) == 0); | |
1272 | assert((bytes & (align - 1)) == 0); | |
61007b31 | 1273 | assert(!qiov || bytes == qiov->size); |
abb06c5a | 1274 | assert((bs->open_flags & BDRV_O_NO_IO) == 0); |
1a62d0ac EB |
1275 | max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX), |
1276 | align); | |
a604fa2b EB |
1277 | |
1278 | /* TODO: We would need a per-BDS .supported_read_flags and | |
1279 | * potential fallback support, if we ever implement any read flags | |
1280 | * to pass through to drivers. For now, there aren't any | |
1281 | * passthrough flags. */ | |
1282 | assert(!(flags & ~(BDRV_REQ_NO_SERIALISING | BDRV_REQ_COPY_ON_READ))); | |
61007b31 SH |
1283 | |
1284 | /* Handle Copy on Read and associated serialisation */ | |
1285 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
1286 | /* If we touch the same cluster it counts as an overlap. This | |
1287 | * guarantees that allocating writes will be serialized and not race | |
1288 | * with each other for the same cluster. For example, in copy-on-read | |
1289 | * it ensures that the CoR read and write operations are atomic and | |
1290 | * guest writes cannot interleave between them. */ | |
1291 | mark_request_serialising(req, bdrv_get_cluster_size(bs)); | |
1292 | } | |
1293 | ||
61408b25 FZ |
1294 | if (!(flags & BDRV_REQ_NO_SERIALISING)) { |
1295 | wait_serialising_requests(req); | |
1296 | } | |
61007b31 SH |
1297 | |
1298 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
d6a644bb | 1299 | int64_t pnum; |
61007b31 | 1300 | |
88e63df2 | 1301 | ret = bdrv_is_allocated(bs, offset, bytes, &pnum); |
61007b31 SH |
1302 | if (ret < 0) { |
1303 | goto out; | |
1304 | } | |
1305 | ||
88e63df2 | 1306 | if (!ret || pnum != bytes) { |
85c97ca7 | 1307 | ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov); |
61007b31 SH |
1308 | goto out; |
1309 | } | |
1310 | } | |
1311 | ||
1a62d0ac | 1312 | /* Forward the request to the BlockDriver, possibly fragmenting it */ |
c9d20029 KW |
1313 | total_bytes = bdrv_getlength(bs); |
1314 | if (total_bytes < 0) { | |
1315 | ret = total_bytes; | |
1316 | goto out; | |
1317 | } | |
61007b31 | 1318 | |
c9d20029 | 1319 | max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align); |
1a62d0ac | 1320 | if (bytes <= max_bytes && bytes <= max_transfer) { |
c9d20029 | 1321 | ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0); |
1a62d0ac EB |
1322 | goto out; |
1323 | } | |
61007b31 | 1324 | |
1a62d0ac EB |
1325 | while (bytes_remaining) { |
1326 | int num; | |
61007b31 | 1327 | |
1a62d0ac EB |
1328 | if (max_bytes) { |
1329 | QEMUIOVector local_qiov; | |
61007b31 | 1330 | |
1a62d0ac EB |
1331 | num = MIN(bytes_remaining, MIN(max_bytes, max_transfer)); |
1332 | assert(num); | |
1333 | qemu_iovec_init(&local_qiov, qiov->niov); | |
1334 | qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num); | |
61007b31 | 1335 | |
1a62d0ac EB |
1336 | ret = bdrv_driver_preadv(bs, offset + bytes - bytes_remaining, |
1337 | num, &local_qiov, 0); | |
1338 | max_bytes -= num; | |
1339 | qemu_iovec_destroy(&local_qiov); | |
1340 | } else { | |
1341 | num = bytes_remaining; | |
1342 | ret = qemu_iovec_memset(qiov, bytes - bytes_remaining, 0, | |
1343 | bytes_remaining); | |
1344 | } | |
1345 | if (ret < 0) { | |
1346 | goto out; | |
1347 | } | |
1348 | bytes_remaining -= num; | |
61007b31 SH |
1349 | } |
1350 | ||
1351 | out: | |
1a62d0ac | 1352 | return ret < 0 ? ret : 0; |
61007b31 SH |
1353 | } |
1354 | ||
61007b31 SH |
1355 | /* |
1356 | * Handle a read request in coroutine context | |
1357 | */ | |
a03ef88f | 1358 | int coroutine_fn bdrv_co_preadv(BdrvChild *child, |
61007b31 SH |
1359 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, |
1360 | BdrvRequestFlags flags) | |
1361 | { | |
a03ef88f | 1362 | BlockDriverState *bs = child->bs; |
61007b31 SH |
1363 | BlockDriver *drv = bs->drv; |
1364 | BdrvTrackedRequest req; | |
1365 | ||
a5b8dd2c | 1366 | uint64_t align = bs->bl.request_alignment; |
61007b31 SH |
1367 | uint8_t *head_buf = NULL; |
1368 | uint8_t *tail_buf = NULL; | |
1369 | QEMUIOVector local_qiov; | |
1370 | bool use_local_qiov = false; | |
1371 | int ret; | |
1372 | ||
f42cf447 DB |
1373 | trace_bdrv_co_preadv(child->bs, offset, bytes, flags); |
1374 | ||
61007b31 SH |
1375 | if (!drv) { |
1376 | return -ENOMEDIUM; | |
1377 | } | |
1378 | ||
1379 | ret = bdrv_check_byte_request(bs, offset, bytes); | |
1380 | if (ret < 0) { | |
1381 | return ret; | |
1382 | } | |
1383 | ||
99723548 PB |
1384 | bdrv_inc_in_flight(bs); |
1385 | ||
9568b511 | 1386 | /* Don't do copy-on-read if we read data before write operation */ |
d3faa13e | 1387 | if (atomic_read(&bs->copy_on_read) && !(flags & BDRV_REQ_NO_SERIALISING)) { |
61007b31 SH |
1388 | flags |= BDRV_REQ_COPY_ON_READ; |
1389 | } | |
1390 | ||
61007b31 SH |
1391 | /* Align read if necessary by padding qiov */ |
1392 | if (offset & (align - 1)) { | |
1393 | head_buf = qemu_blockalign(bs, align); | |
1394 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
1395 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
1396 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1397 | use_local_qiov = true; | |
1398 | ||
1399 | bytes += offset & (align - 1); | |
1400 | offset = offset & ~(align - 1); | |
1401 | } | |
1402 | ||
1403 | if ((offset + bytes) & (align - 1)) { | |
1404 | if (!use_local_qiov) { | |
1405 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
1406 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1407 | use_local_qiov = true; | |
1408 | } | |
1409 | tail_buf = qemu_blockalign(bs, align); | |
1410 | qemu_iovec_add(&local_qiov, tail_buf, | |
1411 | align - ((offset + bytes) & (align - 1))); | |
1412 | ||
1413 | bytes = ROUND_UP(bytes, align); | |
1414 | } | |
1415 | ||
ebde595c | 1416 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ); |
85c97ca7 | 1417 | ret = bdrv_aligned_preadv(child, &req, offset, bytes, align, |
61007b31 SH |
1418 | use_local_qiov ? &local_qiov : qiov, |
1419 | flags); | |
1420 | tracked_request_end(&req); | |
99723548 | 1421 | bdrv_dec_in_flight(bs); |
61007b31 SH |
1422 | |
1423 | if (use_local_qiov) { | |
1424 | qemu_iovec_destroy(&local_qiov); | |
1425 | qemu_vfree(head_buf); | |
1426 | qemu_vfree(tail_buf); | |
1427 | } | |
1428 | ||
1429 | return ret; | |
1430 | } | |
1431 | ||
d05aa8bb | 1432 | static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, |
f5a5ca79 | 1433 | int64_t offset, int bytes, BdrvRequestFlags flags) |
61007b31 SH |
1434 | { |
1435 | BlockDriver *drv = bs->drv; | |
1436 | QEMUIOVector qiov; | |
1437 | struct iovec iov = {0}; | |
1438 | int ret = 0; | |
465fe887 | 1439 | bool need_flush = false; |
443668ca DL |
1440 | int head = 0; |
1441 | int tail = 0; | |
61007b31 | 1442 | |
cf081fca | 1443 | int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX); |
a5b8dd2c EB |
1444 | int alignment = MAX(bs->bl.pwrite_zeroes_alignment, |
1445 | bs->bl.request_alignment); | |
cb2e2878 | 1446 | int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, MAX_BOUNCE_BUFFER); |
d05aa8bb | 1447 | |
d470ad42 HR |
1448 | if (!drv) { |
1449 | return -ENOMEDIUM; | |
1450 | } | |
1451 | ||
b8d0a980 EB |
1452 | assert(alignment % bs->bl.request_alignment == 0); |
1453 | head = offset % alignment; | |
f5a5ca79 | 1454 | tail = (offset + bytes) % alignment; |
b8d0a980 EB |
1455 | max_write_zeroes = QEMU_ALIGN_DOWN(max_write_zeroes, alignment); |
1456 | assert(max_write_zeroes >= bs->bl.request_alignment); | |
61007b31 | 1457 | |
f5a5ca79 MP |
1458 | while (bytes > 0 && !ret) { |
1459 | int num = bytes; | |
61007b31 SH |
1460 | |
1461 | /* Align request. Block drivers can expect the "bulk" of the request | |
443668ca DL |
1462 | * to be aligned, and that unaligned requests do not cross cluster |
1463 | * boundaries. | |
61007b31 | 1464 | */ |
443668ca | 1465 | if (head) { |
b2f95fee EB |
1466 | /* Make a small request up to the first aligned sector. For |
1467 | * convenience, limit this request to max_transfer even if | |
1468 | * we don't need to fall back to writes. */ | |
f5a5ca79 | 1469 | num = MIN(MIN(bytes, max_transfer), alignment - head); |
b2f95fee EB |
1470 | head = (head + num) % alignment; |
1471 | assert(num < max_write_zeroes); | |
d05aa8bb | 1472 | } else if (tail && num > alignment) { |
443668ca DL |
1473 | /* Shorten the request to the last aligned sector. */ |
1474 | num -= tail; | |
61007b31 SH |
1475 | } |
1476 | ||
1477 | /* limit request size */ | |
1478 | if (num > max_write_zeroes) { | |
1479 | num = max_write_zeroes; | |
1480 | } | |
1481 | ||
1482 | ret = -ENOTSUP; | |
1483 | /* First try the efficient write zeroes operation */ | |
d05aa8bb EB |
1484 | if (drv->bdrv_co_pwrite_zeroes) { |
1485 | ret = drv->bdrv_co_pwrite_zeroes(bs, offset, num, | |
1486 | flags & bs->supported_zero_flags); | |
1487 | if (ret != -ENOTSUP && (flags & BDRV_REQ_FUA) && | |
1488 | !(bs->supported_zero_flags & BDRV_REQ_FUA)) { | |
1489 | need_flush = true; | |
1490 | } | |
465fe887 EB |
1491 | } else { |
1492 | assert(!bs->supported_zero_flags); | |
61007b31 SH |
1493 | } |
1494 | ||
1495 | if (ret == -ENOTSUP) { | |
1496 | /* Fall back to bounce buffer if write zeroes is unsupported */ | |
465fe887 EB |
1497 | BdrvRequestFlags write_flags = flags & ~BDRV_REQ_ZERO_WRITE; |
1498 | ||
1499 | if ((flags & BDRV_REQ_FUA) && | |
1500 | !(bs->supported_write_flags & BDRV_REQ_FUA)) { | |
1501 | /* No need for bdrv_driver_pwrite() to do a fallback | |
1502 | * flush on each chunk; use just one at the end */ | |
1503 | write_flags &= ~BDRV_REQ_FUA; | |
1504 | need_flush = true; | |
1505 | } | |
5def6b80 | 1506 | num = MIN(num, max_transfer); |
d05aa8bb | 1507 | iov.iov_len = num; |
61007b31 | 1508 | if (iov.iov_base == NULL) { |
d05aa8bb | 1509 | iov.iov_base = qemu_try_blockalign(bs, num); |
61007b31 SH |
1510 | if (iov.iov_base == NULL) { |
1511 | ret = -ENOMEM; | |
1512 | goto fail; | |
1513 | } | |
d05aa8bb | 1514 | memset(iov.iov_base, 0, num); |
61007b31 SH |
1515 | } |
1516 | qemu_iovec_init_external(&qiov, &iov, 1); | |
1517 | ||
d05aa8bb | 1518 | ret = bdrv_driver_pwritev(bs, offset, num, &qiov, write_flags); |
61007b31 SH |
1519 | |
1520 | /* Keep bounce buffer around if it is big enough for all | |
1521 | * all future requests. | |
1522 | */ | |
5def6b80 | 1523 | if (num < max_transfer) { |
61007b31 SH |
1524 | qemu_vfree(iov.iov_base); |
1525 | iov.iov_base = NULL; | |
1526 | } | |
1527 | } | |
1528 | ||
d05aa8bb | 1529 | offset += num; |
f5a5ca79 | 1530 | bytes -= num; |
61007b31 SH |
1531 | } |
1532 | ||
1533 | fail: | |
465fe887 EB |
1534 | if (ret == 0 && need_flush) { |
1535 | ret = bdrv_co_flush(bs); | |
1536 | } | |
61007b31 SH |
1537 | qemu_vfree(iov.iov_base); |
1538 | return ret; | |
1539 | } | |
1540 | ||
1541 | /* | |
04ed95f4 EB |
1542 | * Forwards an already correctly aligned write request to the BlockDriver, |
1543 | * after possibly fragmenting it. | |
61007b31 | 1544 | */ |
85c97ca7 | 1545 | static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child, |
61007b31 | 1546 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, |
cff86b38 | 1547 | int64_t align, QEMUIOVector *qiov, int flags) |
61007b31 | 1548 | { |
85c97ca7 | 1549 | BlockDriverState *bs = child->bs; |
61007b31 SH |
1550 | BlockDriver *drv = bs->drv; |
1551 | bool waited; | |
1552 | int ret; | |
1553 | ||
9896c876 | 1554 | int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE); |
04ed95f4 EB |
1555 | uint64_t bytes_remaining = bytes; |
1556 | int max_transfer; | |
61007b31 | 1557 | |
d470ad42 HR |
1558 | if (!drv) { |
1559 | return -ENOMEDIUM; | |
1560 | } | |
1561 | ||
d6883bc9 VSO |
1562 | if (bdrv_has_readonly_bitmaps(bs)) { |
1563 | return -EPERM; | |
1564 | } | |
1565 | ||
cff86b38 EB |
1566 | assert(is_power_of_2(align)); |
1567 | assert((offset & (align - 1)) == 0); | |
1568 | assert((bytes & (align - 1)) == 0); | |
61007b31 | 1569 | assert(!qiov || bytes == qiov->size); |
abb06c5a | 1570 | assert((bs->open_flags & BDRV_O_NO_IO) == 0); |
fa166538 | 1571 | assert(!(flags & ~BDRV_REQ_MASK)); |
04ed95f4 EB |
1572 | max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX), |
1573 | align); | |
61007b31 SH |
1574 | |
1575 | waited = wait_serialising_requests(req); | |
1576 | assert(!waited || !req->serialising); | |
1577 | assert(req->overlap_offset <= offset); | |
1578 | assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); | |
c6035964 HR |
1579 | if (flags & BDRV_REQ_WRITE_UNCHANGED) { |
1580 | assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE)); | |
1581 | } else { | |
1582 | assert(child->perm & BLK_PERM_WRITE); | |
1583 | } | |
362b3786 | 1584 | assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE); |
61007b31 SH |
1585 | |
1586 | ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); | |
1587 | ||
1588 | if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF && | |
c1499a5e | 1589 | !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_pwrite_zeroes && |
61007b31 SH |
1590 | qemu_iovec_is_zero(qiov)) { |
1591 | flags |= BDRV_REQ_ZERO_WRITE; | |
1592 | if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) { | |
1593 | flags |= BDRV_REQ_MAY_UNMAP; | |
1594 | } | |
1595 | } | |
1596 | ||
1597 | if (ret < 0) { | |
1598 | /* Do nothing, write notifier decided to fail this request */ | |
1599 | } else if (flags & BDRV_REQ_ZERO_WRITE) { | |
9a4f4c31 | 1600 | bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO); |
9896c876 | 1601 | ret = bdrv_co_do_pwrite_zeroes(bs, offset, bytes, flags); |
3ea1a091 PB |
1602 | } else if (flags & BDRV_REQ_WRITE_COMPRESSED) { |
1603 | ret = bdrv_driver_pwritev_compressed(bs, offset, bytes, qiov); | |
04ed95f4 | 1604 | } else if (bytes <= max_transfer) { |
9a4f4c31 | 1605 | bdrv_debug_event(bs, BLKDBG_PWRITEV); |
78a07294 | 1606 | ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, flags); |
04ed95f4 EB |
1607 | } else { |
1608 | bdrv_debug_event(bs, BLKDBG_PWRITEV); | |
1609 | while (bytes_remaining) { | |
1610 | int num = MIN(bytes_remaining, max_transfer); | |
1611 | QEMUIOVector local_qiov; | |
1612 | int local_flags = flags; | |
1613 | ||
1614 | assert(num); | |
1615 | if (num < bytes_remaining && (flags & BDRV_REQ_FUA) && | |
1616 | !(bs->supported_write_flags & BDRV_REQ_FUA)) { | |
1617 | /* If FUA is going to be emulated by flush, we only | |
1618 | * need to flush on the last iteration */ | |
1619 | local_flags &= ~BDRV_REQ_FUA; | |
1620 | } | |
1621 | qemu_iovec_init(&local_qiov, qiov->niov); | |
1622 | qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num); | |
1623 | ||
1624 | ret = bdrv_driver_pwritev(bs, offset + bytes - bytes_remaining, | |
1625 | num, &local_qiov, local_flags); | |
1626 | qemu_iovec_destroy(&local_qiov); | |
1627 | if (ret < 0) { | |
1628 | break; | |
1629 | } | |
1630 | bytes_remaining -= num; | |
1631 | } | |
61007b31 | 1632 | } |
9a4f4c31 | 1633 | bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE); |
61007b31 | 1634 | |
47fec599 | 1635 | atomic_inc(&bs->write_gen); |
0fdf1a4f | 1636 | bdrv_set_dirty(bs, offset, bytes); |
61007b31 | 1637 | |
f7946da2 | 1638 | stat64_max(&bs->wr_highest_offset, offset + bytes); |
61007b31 SH |
1639 | |
1640 | if (ret >= 0) { | |
9896c876 | 1641 | bs->total_sectors = MAX(bs->total_sectors, end_sector); |
04ed95f4 | 1642 | ret = 0; |
61007b31 SH |
1643 | } |
1644 | ||
1645 | return ret; | |
1646 | } | |
1647 | ||
85c97ca7 | 1648 | static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child, |
9eeb6dd1 FZ |
1649 | int64_t offset, |
1650 | unsigned int bytes, | |
1651 | BdrvRequestFlags flags, | |
1652 | BdrvTrackedRequest *req) | |
1653 | { | |
85c97ca7 | 1654 | BlockDriverState *bs = child->bs; |
9eeb6dd1 FZ |
1655 | uint8_t *buf = NULL; |
1656 | QEMUIOVector local_qiov; | |
1657 | struct iovec iov; | |
a5b8dd2c | 1658 | uint64_t align = bs->bl.request_alignment; |
9eeb6dd1 FZ |
1659 | unsigned int head_padding_bytes, tail_padding_bytes; |
1660 | int ret = 0; | |
1661 | ||
1662 | head_padding_bytes = offset & (align - 1); | |
f13ce1be | 1663 | tail_padding_bytes = (align - (offset + bytes)) & (align - 1); |
9eeb6dd1 FZ |
1664 | |
1665 | ||
1666 | assert(flags & BDRV_REQ_ZERO_WRITE); | |
1667 | if (head_padding_bytes || tail_padding_bytes) { | |
1668 | buf = qemu_blockalign(bs, align); | |
1669 | iov = (struct iovec) { | |
1670 | .iov_base = buf, | |
1671 | .iov_len = align, | |
1672 | }; | |
1673 | qemu_iovec_init_external(&local_qiov, &iov, 1); | |
1674 | } | |
1675 | if (head_padding_bytes) { | |
1676 | uint64_t zero_bytes = MIN(bytes, align - head_padding_bytes); | |
1677 | ||
1678 | /* RMW the unaligned part before head. */ | |
1679 | mark_request_serialising(req, align); | |
1680 | wait_serialising_requests(req); | |
9a4f4c31 | 1681 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); |
85c97ca7 | 1682 | ret = bdrv_aligned_preadv(child, req, offset & ~(align - 1), align, |
9eeb6dd1 FZ |
1683 | align, &local_qiov, 0); |
1684 | if (ret < 0) { | |
1685 | goto fail; | |
1686 | } | |
9a4f4c31 | 1687 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); |
9eeb6dd1 FZ |
1688 | |
1689 | memset(buf + head_padding_bytes, 0, zero_bytes); | |
85c97ca7 | 1690 | ret = bdrv_aligned_pwritev(child, req, offset & ~(align - 1), align, |
cff86b38 | 1691 | align, &local_qiov, |
9eeb6dd1 FZ |
1692 | flags & ~BDRV_REQ_ZERO_WRITE); |
1693 | if (ret < 0) { | |
1694 | goto fail; | |
1695 | } | |
1696 | offset += zero_bytes; | |
1697 | bytes -= zero_bytes; | |
1698 | } | |
1699 | ||
1700 | assert(!bytes || (offset & (align - 1)) == 0); | |
1701 | if (bytes >= align) { | |
1702 | /* Write the aligned part in the middle. */ | |
1703 | uint64_t aligned_bytes = bytes & ~(align - 1); | |
85c97ca7 | 1704 | ret = bdrv_aligned_pwritev(child, req, offset, aligned_bytes, align, |
9eeb6dd1 FZ |
1705 | NULL, flags); |
1706 | if (ret < 0) { | |
1707 | goto fail; | |
1708 | } | |
1709 | bytes -= aligned_bytes; | |
1710 | offset += aligned_bytes; | |
1711 | } | |
1712 | ||
1713 | assert(!bytes || (offset & (align - 1)) == 0); | |
1714 | if (bytes) { | |
1715 | assert(align == tail_padding_bytes + bytes); | |
1716 | /* RMW the unaligned part after tail. */ | |
1717 | mark_request_serialising(req, align); | |
1718 | wait_serialising_requests(req); | |
9a4f4c31 | 1719 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); |
85c97ca7 | 1720 | ret = bdrv_aligned_preadv(child, req, offset, align, |
9eeb6dd1 FZ |
1721 | align, &local_qiov, 0); |
1722 | if (ret < 0) { | |
1723 | goto fail; | |
1724 | } | |
9a4f4c31 | 1725 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); |
9eeb6dd1 FZ |
1726 | |
1727 | memset(buf, 0, bytes); | |
85c97ca7 | 1728 | ret = bdrv_aligned_pwritev(child, req, offset, align, align, |
9eeb6dd1 FZ |
1729 | &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE); |
1730 | } | |
1731 | fail: | |
1732 | qemu_vfree(buf); | |
1733 | return ret; | |
1734 | ||
1735 | } | |
1736 | ||
61007b31 SH |
1737 | /* |
1738 | * Handle a write request in coroutine context | |
1739 | */ | |
a03ef88f | 1740 | int coroutine_fn bdrv_co_pwritev(BdrvChild *child, |
61007b31 SH |
1741 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, |
1742 | BdrvRequestFlags flags) | |
1743 | { | |
a03ef88f | 1744 | BlockDriverState *bs = child->bs; |
61007b31 | 1745 | BdrvTrackedRequest req; |
a5b8dd2c | 1746 | uint64_t align = bs->bl.request_alignment; |
61007b31 SH |
1747 | uint8_t *head_buf = NULL; |
1748 | uint8_t *tail_buf = NULL; | |
1749 | QEMUIOVector local_qiov; | |
1750 | bool use_local_qiov = false; | |
1751 | int ret; | |
1752 | ||
f42cf447 DB |
1753 | trace_bdrv_co_pwritev(child->bs, offset, bytes, flags); |
1754 | ||
61007b31 SH |
1755 | if (!bs->drv) { |
1756 | return -ENOMEDIUM; | |
1757 | } | |
1758 | if (bs->read_only) { | |
eaf5fe2d | 1759 | return -EPERM; |
61007b31 | 1760 | } |
04c01a5c | 1761 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); |
61007b31 SH |
1762 | |
1763 | ret = bdrv_check_byte_request(bs, offset, bytes); | |
1764 | if (ret < 0) { | |
1765 | return ret; | |
1766 | } | |
1767 | ||
99723548 | 1768 | bdrv_inc_in_flight(bs); |
61007b31 SH |
1769 | /* |
1770 | * Align write if necessary by performing a read-modify-write cycle. | |
1771 | * Pad qiov with the read parts and be sure to have a tracked request not | |
1772 | * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle. | |
1773 | */ | |
ebde595c | 1774 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE); |
61007b31 | 1775 | |
18a59f03 | 1776 | if (flags & BDRV_REQ_ZERO_WRITE) { |
85c97ca7 | 1777 | ret = bdrv_co_do_zero_pwritev(child, offset, bytes, flags, &req); |
9eeb6dd1 FZ |
1778 | goto out; |
1779 | } | |
1780 | ||
61007b31 SH |
1781 | if (offset & (align - 1)) { |
1782 | QEMUIOVector head_qiov; | |
1783 | struct iovec head_iov; | |
1784 | ||
1785 | mark_request_serialising(&req, align); | |
1786 | wait_serialising_requests(&req); | |
1787 | ||
1788 | head_buf = qemu_blockalign(bs, align); | |
1789 | head_iov = (struct iovec) { | |
1790 | .iov_base = head_buf, | |
1791 | .iov_len = align, | |
1792 | }; | |
1793 | qemu_iovec_init_external(&head_qiov, &head_iov, 1); | |
1794 | ||
9a4f4c31 | 1795 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); |
85c97ca7 | 1796 | ret = bdrv_aligned_preadv(child, &req, offset & ~(align - 1), align, |
61007b31 SH |
1797 | align, &head_qiov, 0); |
1798 | if (ret < 0) { | |
1799 | goto fail; | |
1800 | } | |
9a4f4c31 | 1801 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); |
61007b31 SH |
1802 | |
1803 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
1804 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
1805 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1806 | use_local_qiov = true; | |
1807 | ||
1808 | bytes += offset & (align - 1); | |
1809 | offset = offset & ~(align - 1); | |
117bc3fa PL |
1810 | |
1811 | /* We have read the tail already if the request is smaller | |
1812 | * than one aligned block. | |
1813 | */ | |
1814 | if (bytes < align) { | |
1815 | qemu_iovec_add(&local_qiov, head_buf + bytes, align - bytes); | |
1816 | bytes = align; | |
1817 | } | |
61007b31 SH |
1818 | } |
1819 | ||
1820 | if ((offset + bytes) & (align - 1)) { | |
1821 | QEMUIOVector tail_qiov; | |
1822 | struct iovec tail_iov; | |
1823 | size_t tail_bytes; | |
1824 | bool waited; | |
1825 | ||
1826 | mark_request_serialising(&req, align); | |
1827 | waited = wait_serialising_requests(&req); | |
1828 | assert(!waited || !use_local_qiov); | |
1829 | ||
1830 | tail_buf = qemu_blockalign(bs, align); | |
1831 | tail_iov = (struct iovec) { | |
1832 | .iov_base = tail_buf, | |
1833 | .iov_len = align, | |
1834 | }; | |
1835 | qemu_iovec_init_external(&tail_qiov, &tail_iov, 1); | |
1836 | ||
9a4f4c31 | 1837 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); |
85c97ca7 KW |
1838 | ret = bdrv_aligned_preadv(child, &req, (offset + bytes) & ~(align - 1), |
1839 | align, align, &tail_qiov, 0); | |
61007b31 SH |
1840 | if (ret < 0) { |
1841 | goto fail; | |
1842 | } | |
9a4f4c31 | 1843 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); |
61007b31 SH |
1844 | |
1845 | if (!use_local_qiov) { | |
1846 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
1847 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
1848 | use_local_qiov = true; | |
1849 | } | |
1850 | ||
1851 | tail_bytes = (offset + bytes) & (align - 1); | |
1852 | qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes); | |
1853 | ||
1854 | bytes = ROUND_UP(bytes, align); | |
1855 | } | |
1856 | ||
85c97ca7 | 1857 | ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align, |
3ea1a091 PB |
1858 | use_local_qiov ? &local_qiov : qiov, |
1859 | flags); | |
61007b31 SH |
1860 | |
1861 | fail: | |
61007b31 SH |
1862 | |
1863 | if (use_local_qiov) { | |
1864 | qemu_iovec_destroy(&local_qiov); | |
1865 | } | |
1866 | qemu_vfree(head_buf); | |
1867 | qemu_vfree(tail_buf); | |
9eeb6dd1 FZ |
1868 | out: |
1869 | tracked_request_end(&req); | |
99723548 | 1870 | bdrv_dec_in_flight(bs); |
61007b31 SH |
1871 | return ret; |
1872 | } | |
1873 | ||
a03ef88f | 1874 | int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, |
f5a5ca79 | 1875 | int bytes, BdrvRequestFlags flags) |
61007b31 | 1876 | { |
f5a5ca79 | 1877 | trace_bdrv_co_pwrite_zeroes(child->bs, offset, bytes, flags); |
61007b31 | 1878 | |
a03ef88f | 1879 | if (!(child->bs->open_flags & BDRV_O_UNMAP)) { |
61007b31 SH |
1880 | flags &= ~BDRV_REQ_MAY_UNMAP; |
1881 | } | |
61007b31 | 1882 | |
f5a5ca79 | 1883 | return bdrv_co_pwritev(child, offset, bytes, NULL, |
74021bc4 | 1884 | BDRV_REQ_ZERO_WRITE | flags); |
61007b31 SH |
1885 | } |
1886 | ||
4085f5c7 JS |
1887 | /* |
1888 | * Flush ALL BDSes regardless of if they are reachable via a BlkBackend or not. | |
1889 | */ | |
1890 | int bdrv_flush_all(void) | |
1891 | { | |
1892 | BdrvNextIterator it; | |
1893 | BlockDriverState *bs = NULL; | |
1894 | int result = 0; | |
1895 | ||
1896 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
1897 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1898 | int ret; | |
1899 | ||
1900 | aio_context_acquire(aio_context); | |
1901 | ret = bdrv_flush(bs); | |
1902 | if (ret < 0 && !result) { | |
1903 | result = ret; | |
1904 | } | |
1905 | aio_context_release(aio_context); | |
1906 | } | |
1907 | ||
1908 | return result; | |
1909 | } | |
1910 | ||
1911 | ||
4bcd936e | 1912 | typedef struct BdrvCoBlockStatusData { |
61007b31 SH |
1913 | BlockDriverState *bs; |
1914 | BlockDriverState *base; | |
c9ce8c4d | 1915 | bool want_zero; |
4bcd936e EB |
1916 | int64_t offset; |
1917 | int64_t bytes; | |
1918 | int64_t *pnum; | |
1919 | int64_t *map; | |
c9ce8c4d | 1920 | BlockDriverState **file; |
4bcd936e | 1921 | int ret; |
61007b31 | 1922 | bool done; |
4bcd936e | 1923 | } BdrvCoBlockStatusData; |
61007b31 | 1924 | |
3e4d0e72 EB |
1925 | int coroutine_fn bdrv_co_block_status_from_file(BlockDriverState *bs, |
1926 | bool want_zero, | |
1927 | int64_t offset, | |
1928 | int64_t bytes, | |
1929 | int64_t *pnum, | |
1930 | int64_t *map, | |
1931 | BlockDriverState **file) | |
f7cc69b3 MP |
1932 | { |
1933 | assert(bs->file && bs->file->bs); | |
3e4d0e72 EB |
1934 | *pnum = bytes; |
1935 | *map = offset; | |
f7cc69b3 | 1936 | *file = bs->file->bs; |
3e4d0e72 | 1937 | return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID; |
f7cc69b3 MP |
1938 | } |
1939 | ||
3e4d0e72 EB |
1940 | int coroutine_fn bdrv_co_block_status_from_backing(BlockDriverState *bs, |
1941 | bool want_zero, | |
1942 | int64_t offset, | |
1943 | int64_t bytes, | |
1944 | int64_t *pnum, | |
1945 | int64_t *map, | |
1946 | BlockDriverState **file) | |
f7cc69b3 MP |
1947 | { |
1948 | assert(bs->backing && bs->backing->bs); | |
3e4d0e72 EB |
1949 | *pnum = bytes; |
1950 | *map = offset; | |
f7cc69b3 | 1951 | *file = bs->backing->bs; |
3e4d0e72 | 1952 | return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID; |
f7cc69b3 MP |
1953 | } |
1954 | ||
61007b31 SH |
1955 | /* |
1956 | * Returns the allocation status of the specified sectors. | |
1957 | * Drivers not implementing the functionality are assumed to not support | |
1958 | * backing files, hence all their sectors are reported as allocated. | |
1959 | * | |
86a3d5c6 EB |
1960 | * If 'want_zero' is true, the caller is querying for mapping |
1961 | * purposes, with a focus on valid BDRV_BLOCK_OFFSET_VALID, _DATA, and | |
1962 | * _ZERO where possible; otherwise, the result favors larger 'pnum', | |
1963 | * with a focus on accurate BDRV_BLOCK_ALLOCATED. | |
c9ce8c4d | 1964 | * |
2e8bc787 | 1965 | * If 'offset' is beyond the end of the disk image the return value is |
fb0d8654 | 1966 | * BDRV_BLOCK_EOF and 'pnum' is set to 0. |
61007b31 | 1967 | * |
2e8bc787 | 1968 | * 'bytes' is the max value 'pnum' should be set to. If bytes goes |
fb0d8654 EB |
1969 | * beyond the end of the disk image it will be clamped; if 'pnum' is set to |
1970 | * the end of the image, then the returned value will include BDRV_BLOCK_EOF. | |
67a0fd2a | 1971 | * |
2e8bc787 EB |
1972 | * 'pnum' is set to the number of bytes (including and immediately |
1973 | * following the specified offset) that are easily known to be in the | |
1974 | * same allocated/unallocated state. Note that a second call starting | |
1975 | * at the original offset plus returned pnum may have the same status. | |
1976 | * The returned value is non-zero on success except at end-of-file. | |
1977 | * | |
1978 | * Returns negative errno on failure. Otherwise, if the | |
1979 | * BDRV_BLOCK_OFFSET_VALID bit is set, 'map' and 'file' (if non-NULL) are | |
1980 | * set to the host mapping and BDS corresponding to the guest offset. | |
61007b31 | 1981 | */ |
2e8bc787 EB |
1982 | static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs, |
1983 | bool want_zero, | |
1984 | int64_t offset, int64_t bytes, | |
1985 | int64_t *pnum, int64_t *map, | |
1986 | BlockDriverState **file) | |
1987 | { | |
1988 | int64_t total_size; | |
1989 | int64_t n; /* bytes */ | |
efa6e2ed | 1990 | int ret; |
2e8bc787 | 1991 | int64_t local_map = 0; |
298a1665 | 1992 | BlockDriverState *local_file = NULL; |
efa6e2ed EB |
1993 | int64_t aligned_offset, aligned_bytes; |
1994 | uint32_t align; | |
61007b31 | 1995 | |
298a1665 EB |
1996 | assert(pnum); |
1997 | *pnum = 0; | |
2e8bc787 EB |
1998 | total_size = bdrv_getlength(bs); |
1999 | if (total_size < 0) { | |
2000 | ret = total_size; | |
298a1665 | 2001 | goto early_out; |
61007b31 SH |
2002 | } |
2003 | ||
2e8bc787 | 2004 | if (offset >= total_size) { |
298a1665 EB |
2005 | ret = BDRV_BLOCK_EOF; |
2006 | goto early_out; | |
61007b31 | 2007 | } |
2e8bc787 | 2008 | if (!bytes) { |
298a1665 EB |
2009 | ret = 0; |
2010 | goto early_out; | |
9cdcfd9f | 2011 | } |
61007b31 | 2012 | |
2e8bc787 EB |
2013 | n = total_size - offset; |
2014 | if (n < bytes) { | |
2015 | bytes = n; | |
61007b31 SH |
2016 | } |
2017 | ||
d470ad42 HR |
2018 | /* Must be non-NULL or bdrv_getlength() would have failed */ |
2019 | assert(bs->drv); | |
636cb512 | 2020 | if (!bs->drv->bdrv_co_block_status) { |
2e8bc787 | 2021 | *pnum = bytes; |
61007b31 | 2022 | ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED; |
2e8bc787 | 2023 | if (offset + bytes == total_size) { |
fb0d8654 EB |
2024 | ret |= BDRV_BLOCK_EOF; |
2025 | } | |
61007b31 | 2026 | if (bs->drv->protocol_name) { |
2e8bc787 EB |
2027 | ret |= BDRV_BLOCK_OFFSET_VALID; |
2028 | local_map = offset; | |
298a1665 | 2029 | local_file = bs; |
61007b31 | 2030 | } |
298a1665 | 2031 | goto early_out; |
61007b31 SH |
2032 | } |
2033 | ||
99723548 | 2034 | bdrv_inc_in_flight(bs); |
efa6e2ed EB |
2035 | |
2036 | /* Round out to request_alignment boundaries */ | |
86a3d5c6 | 2037 | align = bs->bl.request_alignment; |
efa6e2ed EB |
2038 | aligned_offset = QEMU_ALIGN_DOWN(offset, align); |
2039 | aligned_bytes = ROUND_UP(offset + bytes, align) - aligned_offset; | |
2040 | ||
636cb512 EB |
2041 | ret = bs->drv->bdrv_co_block_status(bs, want_zero, aligned_offset, |
2042 | aligned_bytes, pnum, &local_map, | |
2043 | &local_file); | |
2044 | if (ret < 0) { | |
2045 | *pnum = 0; | |
2046 | goto out; | |
efa6e2ed EB |
2047 | } |
2048 | ||
2e8bc787 | 2049 | /* |
636cb512 | 2050 | * The driver's result must be a non-zero multiple of request_alignment. |
efa6e2ed | 2051 | * Clamp pnum and adjust map to original request. |
2e8bc787 | 2052 | */ |
636cb512 EB |
2053 | assert(*pnum && QEMU_IS_ALIGNED(*pnum, align) && |
2054 | align > offset - aligned_offset); | |
efa6e2ed EB |
2055 | *pnum -= offset - aligned_offset; |
2056 | if (*pnum > bytes) { | |
2057 | *pnum = bytes; | |
61007b31 | 2058 | } |
2e8bc787 | 2059 | if (ret & BDRV_BLOCK_OFFSET_VALID) { |
efa6e2ed | 2060 | local_map += offset - aligned_offset; |
2e8bc787 | 2061 | } |
61007b31 SH |
2062 | |
2063 | if (ret & BDRV_BLOCK_RAW) { | |
298a1665 | 2064 | assert(ret & BDRV_BLOCK_OFFSET_VALID && local_file); |
2e8bc787 EB |
2065 | ret = bdrv_co_block_status(local_file, want_zero, local_map, |
2066 | *pnum, pnum, &local_map, &local_file); | |
99723548 | 2067 | goto out; |
61007b31 SH |
2068 | } |
2069 | ||
2070 | if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { | |
2071 | ret |= BDRV_BLOCK_ALLOCATED; | |
c9ce8c4d | 2072 | } else if (want_zero) { |
61007b31 SH |
2073 | if (bdrv_unallocated_blocks_are_zero(bs)) { |
2074 | ret |= BDRV_BLOCK_ZERO; | |
760e0063 KW |
2075 | } else if (bs->backing) { |
2076 | BlockDriverState *bs2 = bs->backing->bs; | |
2e8bc787 | 2077 | int64_t size2 = bdrv_getlength(bs2); |
c9ce8c4d | 2078 | |
2e8bc787 | 2079 | if (size2 >= 0 && offset >= size2) { |
61007b31 SH |
2080 | ret |= BDRV_BLOCK_ZERO; |
2081 | } | |
2082 | } | |
2083 | } | |
2084 | ||
c9ce8c4d | 2085 | if (want_zero && local_file && local_file != bs && |
61007b31 SH |
2086 | (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && |
2087 | (ret & BDRV_BLOCK_OFFSET_VALID)) { | |
2e8bc787 EB |
2088 | int64_t file_pnum; |
2089 | int ret2; | |
61007b31 | 2090 | |
2e8bc787 EB |
2091 | ret2 = bdrv_co_block_status(local_file, want_zero, local_map, |
2092 | *pnum, &file_pnum, NULL, NULL); | |
61007b31 SH |
2093 | if (ret2 >= 0) { |
2094 | /* Ignore errors. This is just providing extra information, it | |
2095 | * is useful but not necessary. | |
2096 | */ | |
c61e684e EB |
2097 | if (ret2 & BDRV_BLOCK_EOF && |
2098 | (!file_pnum || ret2 & BDRV_BLOCK_ZERO)) { | |
2099 | /* | |
2100 | * It is valid for the format block driver to read | |
2101 | * beyond the end of the underlying file's current | |
2102 | * size; such areas read as zero. | |
2103 | */ | |
61007b31 SH |
2104 | ret |= BDRV_BLOCK_ZERO; |
2105 | } else { | |
2106 | /* Limit request to the range reported by the protocol driver */ | |
2107 | *pnum = file_pnum; | |
2108 | ret |= (ret2 & BDRV_BLOCK_ZERO); | |
2109 | } | |
2110 | } | |
2111 | } | |
2112 | ||
99723548 PB |
2113 | out: |
2114 | bdrv_dec_in_flight(bs); | |
2e8bc787 | 2115 | if (ret >= 0 && offset + *pnum == total_size) { |
fb0d8654 EB |
2116 | ret |= BDRV_BLOCK_EOF; |
2117 | } | |
298a1665 EB |
2118 | early_out: |
2119 | if (file) { | |
2120 | *file = local_file; | |
2121 | } | |
2e8bc787 EB |
2122 | if (map) { |
2123 | *map = local_map; | |
2124 | } | |
61007b31 SH |
2125 | return ret; |
2126 | } | |
2127 | ||
5b648c67 EB |
2128 | static int coroutine_fn bdrv_co_block_status_above(BlockDriverState *bs, |
2129 | BlockDriverState *base, | |
2130 | bool want_zero, | |
2131 | int64_t offset, | |
2132 | int64_t bytes, | |
2133 | int64_t *pnum, | |
2134 | int64_t *map, | |
2135 | BlockDriverState **file) | |
ba3f0e25 FZ |
2136 | { |
2137 | BlockDriverState *p; | |
5b648c67 | 2138 | int ret = 0; |
c61e684e | 2139 | bool first = true; |
ba3f0e25 FZ |
2140 | |
2141 | assert(bs != base); | |
760e0063 | 2142 | for (p = bs; p != base; p = backing_bs(p)) { |
5b648c67 EB |
2143 | ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map, |
2144 | file); | |
c61e684e EB |
2145 | if (ret < 0) { |
2146 | break; | |
2147 | } | |
2148 | if (ret & BDRV_BLOCK_ZERO && ret & BDRV_BLOCK_EOF && !first) { | |
2149 | /* | |
2150 | * Reading beyond the end of the file continues to read | |
2151 | * zeroes, but we can only widen the result to the | |
2152 | * unallocated length we learned from an earlier | |
2153 | * iteration. | |
2154 | */ | |
5b648c67 | 2155 | *pnum = bytes; |
c61e684e EB |
2156 | } |
2157 | if (ret & (BDRV_BLOCK_ZERO | BDRV_BLOCK_DATA)) { | |
ba3f0e25 FZ |
2158 | break; |
2159 | } | |
5b648c67 EB |
2160 | /* [offset, pnum] unallocated on this layer, which could be only |
2161 | * the first part of [offset, bytes]. */ | |
2162 | bytes = MIN(bytes, *pnum); | |
c61e684e | 2163 | first = false; |
ba3f0e25 FZ |
2164 | } |
2165 | return ret; | |
2166 | } | |
2167 | ||
31826642 | 2168 | /* Coroutine wrapper for bdrv_block_status_above() */ |
5b648c67 | 2169 | static void coroutine_fn bdrv_block_status_above_co_entry(void *opaque) |
61007b31 | 2170 | { |
4bcd936e | 2171 | BdrvCoBlockStatusData *data = opaque; |
61007b31 | 2172 | |
5b648c67 EB |
2173 | data->ret = bdrv_co_block_status_above(data->bs, data->base, |
2174 | data->want_zero, | |
2175 | data->offset, data->bytes, | |
2176 | data->pnum, data->map, data->file); | |
61007b31 SH |
2177 | data->done = true; |
2178 | } | |
2179 | ||
2180 | /* | |
5b648c67 | 2181 | * Synchronous wrapper around bdrv_co_block_status_above(). |
61007b31 | 2182 | * |
5b648c67 | 2183 | * See bdrv_co_block_status_above() for details. |
61007b31 | 2184 | */ |
7ddb99b9 EB |
2185 | static int bdrv_common_block_status_above(BlockDriverState *bs, |
2186 | BlockDriverState *base, | |
2187 | bool want_zero, int64_t offset, | |
2188 | int64_t bytes, int64_t *pnum, | |
2189 | int64_t *map, | |
2190 | BlockDriverState **file) | |
61007b31 SH |
2191 | { |
2192 | Coroutine *co; | |
4bcd936e | 2193 | BdrvCoBlockStatusData data = { |
61007b31 | 2194 | .bs = bs, |
ba3f0e25 | 2195 | .base = base, |
c9ce8c4d | 2196 | .want_zero = want_zero, |
7ddb99b9 EB |
2197 | .offset = offset, |
2198 | .bytes = bytes, | |
2199 | .pnum = pnum, | |
2200 | .map = map, | |
c9ce8c4d | 2201 | .file = file, |
61007b31 SH |
2202 | .done = false, |
2203 | }; | |
2204 | ||
2205 | if (qemu_in_coroutine()) { | |
2206 | /* Fast-path if already in coroutine context */ | |
5b648c67 | 2207 | bdrv_block_status_above_co_entry(&data); |
61007b31 | 2208 | } else { |
5b648c67 | 2209 | co = qemu_coroutine_create(bdrv_block_status_above_co_entry, &data); |
e92f0e19 | 2210 | bdrv_coroutine_enter(bs, co); |
88b062c2 | 2211 | BDRV_POLL_WHILE(bs, !data.done); |
61007b31 | 2212 | } |
7ddb99b9 | 2213 | return data.ret; |
61007b31 SH |
2214 | } |
2215 | ||
31826642 EB |
2216 | int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, |
2217 | int64_t offset, int64_t bytes, int64_t *pnum, | |
2218 | int64_t *map, BlockDriverState **file) | |
c9ce8c4d | 2219 | { |
31826642 EB |
2220 | return bdrv_common_block_status_above(bs, base, true, offset, bytes, |
2221 | pnum, map, file); | |
c9ce8c4d EB |
2222 | } |
2223 | ||
237d78f8 EB |
2224 | int bdrv_block_status(BlockDriverState *bs, int64_t offset, int64_t bytes, |
2225 | int64_t *pnum, int64_t *map, BlockDriverState **file) | |
ba3f0e25 | 2226 | { |
31826642 EB |
2227 | return bdrv_block_status_above(bs, backing_bs(bs), |
2228 | offset, bytes, pnum, map, file); | |
ba3f0e25 FZ |
2229 | } |
2230 | ||
d6a644bb EB |
2231 | int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset, |
2232 | int64_t bytes, int64_t *pnum) | |
61007b31 | 2233 | { |
7ddb99b9 EB |
2234 | int ret; |
2235 | int64_t dummy; | |
d6a644bb | 2236 | |
7ddb99b9 EB |
2237 | ret = bdrv_common_block_status_above(bs, backing_bs(bs), false, offset, |
2238 | bytes, pnum ? pnum : &dummy, NULL, | |
c9ce8c4d | 2239 | NULL); |
61007b31 SH |
2240 | if (ret < 0) { |
2241 | return ret; | |
2242 | } | |
2243 | return !!(ret & BDRV_BLOCK_ALLOCATED); | |
2244 | } | |
2245 | ||
2246 | /* | |
2247 | * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] | |
2248 | * | |
51b0a488 EB |
2249 | * Return true if (a prefix of) the given range is allocated in any image |
2250 | * between BASE and TOP (inclusive). BASE can be NULL to check if the given | |
2251 | * offset is allocated in any image of the chain. Return false otherwise, | |
d6a644bb | 2252 | * or negative errno on failure. |
61007b31 | 2253 | * |
51b0a488 EB |
2254 | * 'pnum' is set to the number of bytes (including and immediately |
2255 | * following the specified offset) that are known to be in the same | |
2256 | * allocated/unallocated state. Note that a subsequent call starting | |
2257 | * at 'offset + *pnum' may return the same allocation status (in other | |
2258 | * words, the result is not necessarily the maximum possible range); | |
2259 | * but 'pnum' will only be 0 when end of file is reached. | |
61007b31 SH |
2260 | * |
2261 | */ | |
2262 | int bdrv_is_allocated_above(BlockDriverState *top, | |
2263 | BlockDriverState *base, | |
51b0a488 | 2264 | int64_t offset, int64_t bytes, int64_t *pnum) |
61007b31 SH |
2265 | { |
2266 | BlockDriverState *intermediate; | |
51b0a488 EB |
2267 | int ret; |
2268 | int64_t n = bytes; | |
61007b31 SH |
2269 | |
2270 | intermediate = top; | |
2271 | while (intermediate && intermediate != base) { | |
d6a644bb | 2272 | int64_t pnum_inter; |
c00716be | 2273 | int64_t size_inter; |
d6a644bb | 2274 | |
51b0a488 | 2275 | ret = bdrv_is_allocated(intermediate, offset, bytes, &pnum_inter); |
61007b31 SH |
2276 | if (ret < 0) { |
2277 | return ret; | |
d6a644bb | 2278 | } |
d6a644bb | 2279 | if (ret) { |
51b0a488 | 2280 | *pnum = pnum_inter; |
61007b31 SH |
2281 | return 1; |
2282 | } | |
2283 | ||
51b0a488 | 2284 | size_inter = bdrv_getlength(intermediate); |
c00716be EB |
2285 | if (size_inter < 0) { |
2286 | return size_inter; | |
2287 | } | |
51b0a488 EB |
2288 | if (n > pnum_inter && |
2289 | (intermediate == top || offset + pnum_inter < size_inter)) { | |
2290 | n = pnum_inter; | |
61007b31 SH |
2291 | } |
2292 | ||
760e0063 | 2293 | intermediate = backing_bs(intermediate); |
61007b31 SH |
2294 | } |
2295 | ||
2296 | *pnum = n; | |
2297 | return 0; | |
2298 | } | |
2299 | ||
1a8ae822 KW |
2300 | typedef struct BdrvVmstateCo { |
2301 | BlockDriverState *bs; | |
2302 | QEMUIOVector *qiov; | |
2303 | int64_t pos; | |
2304 | bool is_read; | |
2305 | int ret; | |
2306 | } BdrvVmstateCo; | |
2307 | ||
2308 | static int coroutine_fn | |
2309 | bdrv_co_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos, | |
2310 | bool is_read) | |
2311 | { | |
2312 | BlockDriver *drv = bs->drv; | |
dc88a467 SH |
2313 | int ret = -ENOTSUP; |
2314 | ||
2315 | bdrv_inc_in_flight(bs); | |
1a8ae822 KW |
2316 | |
2317 | if (!drv) { | |
dc88a467 | 2318 | ret = -ENOMEDIUM; |
1a8ae822 | 2319 | } else if (drv->bdrv_load_vmstate) { |
dc88a467 SH |
2320 | if (is_read) { |
2321 | ret = drv->bdrv_load_vmstate(bs, qiov, pos); | |
2322 | } else { | |
2323 | ret = drv->bdrv_save_vmstate(bs, qiov, pos); | |
2324 | } | |
1a8ae822 | 2325 | } else if (bs->file) { |
dc88a467 | 2326 | ret = bdrv_co_rw_vmstate(bs->file->bs, qiov, pos, is_read); |
1a8ae822 KW |
2327 | } |
2328 | ||
dc88a467 SH |
2329 | bdrv_dec_in_flight(bs); |
2330 | return ret; | |
1a8ae822 KW |
2331 | } |
2332 | ||
2333 | static void coroutine_fn bdrv_co_rw_vmstate_entry(void *opaque) | |
2334 | { | |
2335 | BdrvVmstateCo *co = opaque; | |
2336 | co->ret = bdrv_co_rw_vmstate(co->bs, co->qiov, co->pos, co->is_read); | |
2337 | } | |
2338 | ||
2339 | static inline int | |
2340 | bdrv_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos, | |
2341 | bool is_read) | |
2342 | { | |
2343 | if (qemu_in_coroutine()) { | |
2344 | return bdrv_co_rw_vmstate(bs, qiov, pos, is_read); | |
2345 | } else { | |
2346 | BdrvVmstateCo data = { | |
2347 | .bs = bs, | |
2348 | .qiov = qiov, | |
2349 | .pos = pos, | |
2350 | .is_read = is_read, | |
2351 | .ret = -EINPROGRESS, | |
2352 | }; | |
0b8b8753 | 2353 | Coroutine *co = qemu_coroutine_create(bdrv_co_rw_vmstate_entry, &data); |
1a8ae822 | 2354 | |
e92f0e19 | 2355 | bdrv_coroutine_enter(bs, co); |
ea17c9d2 | 2356 | BDRV_POLL_WHILE(bs, data.ret == -EINPROGRESS); |
1a8ae822 KW |
2357 | return data.ret; |
2358 | } | |
2359 | } | |
2360 | ||
61007b31 SH |
2361 | int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
2362 | int64_t pos, int size) | |
2363 | { | |
2364 | QEMUIOVector qiov; | |
2365 | struct iovec iov = { | |
2366 | .iov_base = (void *) buf, | |
2367 | .iov_len = size, | |
2368 | }; | |
b433d942 | 2369 | int ret; |
61007b31 SH |
2370 | |
2371 | qemu_iovec_init_external(&qiov, &iov, 1); | |
b433d942 KW |
2372 | |
2373 | ret = bdrv_writev_vmstate(bs, &qiov, pos); | |
2374 | if (ret < 0) { | |
2375 | return ret; | |
2376 | } | |
2377 | ||
2378 | return size; | |
61007b31 SH |
2379 | } |
2380 | ||
2381 | int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) | |
2382 | { | |
1a8ae822 | 2383 | return bdrv_rw_vmstate(bs, qiov, pos, false); |
61007b31 SH |
2384 | } |
2385 | ||
2386 | int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, | |
2387 | int64_t pos, int size) | |
5ddda0b8 KW |
2388 | { |
2389 | QEMUIOVector qiov; | |
2390 | struct iovec iov = { | |
2391 | .iov_base = buf, | |
2392 | .iov_len = size, | |
2393 | }; | |
b433d942 | 2394 | int ret; |
5ddda0b8 KW |
2395 | |
2396 | qemu_iovec_init_external(&qiov, &iov, 1); | |
b433d942 KW |
2397 | ret = bdrv_readv_vmstate(bs, &qiov, pos); |
2398 | if (ret < 0) { | |
2399 | return ret; | |
2400 | } | |
2401 | ||
2402 | return size; | |
5ddda0b8 KW |
2403 | } |
2404 | ||
2405 | int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) | |
61007b31 | 2406 | { |
1a8ae822 | 2407 | return bdrv_rw_vmstate(bs, qiov, pos, true); |
61007b31 SH |
2408 | } |
2409 | ||
2410 | /**************************************************************/ | |
2411 | /* async I/Os */ | |
2412 | ||
61007b31 SH |
2413 | void bdrv_aio_cancel(BlockAIOCB *acb) |
2414 | { | |
2415 | qemu_aio_ref(acb); | |
2416 | bdrv_aio_cancel_async(acb); | |
2417 | while (acb->refcnt > 1) { | |
2418 | if (acb->aiocb_info->get_aio_context) { | |
2419 | aio_poll(acb->aiocb_info->get_aio_context(acb), true); | |
2420 | } else if (acb->bs) { | |
2f47da5f PB |
2421 | /* qemu_aio_ref and qemu_aio_unref are not thread-safe, so |
2422 | * assert that we're not using an I/O thread. Thread-safe | |
2423 | * code should use bdrv_aio_cancel_async exclusively. | |
2424 | */ | |
2425 | assert(bdrv_get_aio_context(acb->bs) == qemu_get_aio_context()); | |
61007b31 SH |
2426 | aio_poll(bdrv_get_aio_context(acb->bs), true); |
2427 | } else { | |
2428 | abort(); | |
2429 | } | |
2430 | } | |
2431 | qemu_aio_unref(acb); | |
2432 | } | |
2433 | ||
2434 | /* Async version of aio cancel. The caller is not blocked if the acb implements | |
2435 | * cancel_async, otherwise we do nothing and let the request normally complete. | |
2436 | * In either case the completion callback must be called. */ | |
2437 | void bdrv_aio_cancel_async(BlockAIOCB *acb) | |
2438 | { | |
2439 | if (acb->aiocb_info->cancel_async) { | |
2440 | acb->aiocb_info->cancel_async(acb); | |
2441 | } | |
2442 | } | |
2443 | ||
61007b31 SH |
2444 | /**************************************************************/ |
2445 | /* Coroutine block device emulation */ | |
2446 | ||
e293b7a3 KW |
2447 | typedef struct FlushCo { |
2448 | BlockDriverState *bs; | |
2449 | int ret; | |
2450 | } FlushCo; | |
2451 | ||
2452 | ||
61007b31 SH |
2453 | static void coroutine_fn bdrv_flush_co_entry(void *opaque) |
2454 | { | |
e293b7a3 | 2455 | FlushCo *rwco = opaque; |
61007b31 SH |
2456 | |
2457 | rwco->ret = bdrv_co_flush(rwco->bs); | |
2458 | } | |
2459 | ||
2460 | int coroutine_fn bdrv_co_flush(BlockDriverState *bs) | |
2461 | { | |
49ca6259 FZ |
2462 | int current_gen; |
2463 | int ret = 0; | |
2464 | ||
2465 | bdrv_inc_in_flight(bs); | |
61007b31 | 2466 | |
e914404e | 2467 | if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || |
1b6bc94d | 2468 | bdrv_is_sg(bs)) { |
49ca6259 | 2469 | goto early_exit; |
61007b31 SH |
2470 | } |
2471 | ||
3783fa3d | 2472 | qemu_co_mutex_lock(&bs->reqs_lock); |
47fec599 | 2473 | current_gen = atomic_read(&bs->write_gen); |
3ff2f67a EY |
2474 | |
2475 | /* Wait until any previous flushes are completed */ | |
99723548 | 2476 | while (bs->active_flush_req) { |
3783fa3d | 2477 | qemu_co_queue_wait(&bs->flush_queue, &bs->reqs_lock); |
3ff2f67a EY |
2478 | } |
2479 | ||
3783fa3d | 2480 | /* Flushes reach this point in nondecreasing current_gen order. */ |
99723548 | 2481 | bs->active_flush_req = true; |
3783fa3d | 2482 | qemu_co_mutex_unlock(&bs->reqs_lock); |
3ff2f67a | 2483 | |
c32b82af PD |
2484 | /* Write back all layers by calling one driver function */ |
2485 | if (bs->drv->bdrv_co_flush) { | |
2486 | ret = bs->drv->bdrv_co_flush(bs); | |
2487 | goto out; | |
2488 | } | |
2489 | ||
61007b31 SH |
2490 | /* Write back cached data to the OS even with cache=unsafe */ |
2491 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); | |
2492 | if (bs->drv->bdrv_co_flush_to_os) { | |
2493 | ret = bs->drv->bdrv_co_flush_to_os(bs); | |
2494 | if (ret < 0) { | |
cdb5e315 | 2495 | goto out; |
61007b31 SH |
2496 | } |
2497 | } | |
2498 | ||
2499 | /* But don't actually force it to the disk with cache=unsafe */ | |
2500 | if (bs->open_flags & BDRV_O_NO_FLUSH) { | |
2501 | goto flush_parent; | |
2502 | } | |
2503 | ||
3ff2f67a EY |
2504 | /* Check if we really need to flush anything */ |
2505 | if (bs->flushed_gen == current_gen) { | |
2506 | goto flush_parent; | |
2507 | } | |
2508 | ||
61007b31 | 2509 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); |
d470ad42 HR |
2510 | if (!bs->drv) { |
2511 | /* bs->drv->bdrv_co_flush() might have ejected the BDS | |
2512 | * (even in case of apparent success) */ | |
2513 | ret = -ENOMEDIUM; | |
2514 | goto out; | |
2515 | } | |
61007b31 SH |
2516 | if (bs->drv->bdrv_co_flush_to_disk) { |
2517 | ret = bs->drv->bdrv_co_flush_to_disk(bs); | |
2518 | } else if (bs->drv->bdrv_aio_flush) { | |
2519 | BlockAIOCB *acb; | |
2520 | CoroutineIOCompletion co = { | |
2521 | .coroutine = qemu_coroutine_self(), | |
2522 | }; | |
2523 | ||
2524 | acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); | |
2525 | if (acb == NULL) { | |
2526 | ret = -EIO; | |
2527 | } else { | |
2528 | qemu_coroutine_yield(); | |
2529 | ret = co.ret; | |
2530 | } | |
2531 | } else { | |
2532 | /* | |
2533 | * Some block drivers always operate in either writethrough or unsafe | |
2534 | * mode and don't support bdrv_flush therefore. Usually qemu doesn't | |
2535 | * know how the server works (because the behaviour is hardcoded or | |
2536 | * depends on server-side configuration), so we can't ensure that | |
2537 | * everything is safe on disk. Returning an error doesn't work because | |
2538 | * that would break guests even if the server operates in writethrough | |
2539 | * mode. | |
2540 | * | |
2541 | * Let's hope the user knows what he's doing. | |
2542 | */ | |
2543 | ret = 0; | |
2544 | } | |
3ff2f67a | 2545 | |
61007b31 | 2546 | if (ret < 0) { |
cdb5e315 | 2547 | goto out; |
61007b31 SH |
2548 | } |
2549 | ||
2550 | /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH | |
2551 | * in the case of cache=unsafe, so there are no useless flushes. | |
2552 | */ | |
2553 | flush_parent: | |
cdb5e315 FZ |
2554 | ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0; |
2555 | out: | |
3ff2f67a | 2556 | /* Notify any pending flushes that we have completed */ |
e6af1e08 KW |
2557 | if (ret == 0) { |
2558 | bs->flushed_gen = current_gen; | |
2559 | } | |
3783fa3d PB |
2560 | |
2561 | qemu_co_mutex_lock(&bs->reqs_lock); | |
99723548 | 2562 | bs->active_flush_req = false; |
156af3ac DL |
2563 | /* Return value is ignored - it's ok if wait queue is empty */ |
2564 | qemu_co_queue_next(&bs->flush_queue); | |
3783fa3d | 2565 | qemu_co_mutex_unlock(&bs->reqs_lock); |
3ff2f67a | 2566 | |
49ca6259 | 2567 | early_exit: |
99723548 | 2568 | bdrv_dec_in_flight(bs); |
cdb5e315 | 2569 | return ret; |
61007b31 SH |
2570 | } |
2571 | ||
2572 | int bdrv_flush(BlockDriverState *bs) | |
2573 | { | |
2574 | Coroutine *co; | |
e293b7a3 | 2575 | FlushCo flush_co = { |
61007b31 SH |
2576 | .bs = bs, |
2577 | .ret = NOT_DONE, | |
2578 | }; | |
2579 | ||
2580 | if (qemu_in_coroutine()) { | |
2581 | /* Fast-path if already in coroutine context */ | |
e293b7a3 | 2582 | bdrv_flush_co_entry(&flush_co); |
61007b31 | 2583 | } else { |
0b8b8753 | 2584 | co = qemu_coroutine_create(bdrv_flush_co_entry, &flush_co); |
e92f0e19 | 2585 | bdrv_coroutine_enter(bs, co); |
88b062c2 | 2586 | BDRV_POLL_WHILE(bs, flush_co.ret == NOT_DONE); |
61007b31 SH |
2587 | } |
2588 | ||
e293b7a3 | 2589 | return flush_co.ret; |
61007b31 SH |
2590 | } |
2591 | ||
2592 | typedef struct DiscardCo { | |
2593 | BlockDriverState *bs; | |
0c51a893 | 2594 | int64_t offset; |
f5a5ca79 | 2595 | int bytes; |
61007b31 SH |
2596 | int ret; |
2597 | } DiscardCo; | |
0c51a893 | 2598 | static void coroutine_fn bdrv_pdiscard_co_entry(void *opaque) |
61007b31 SH |
2599 | { |
2600 | DiscardCo *rwco = opaque; | |
2601 | ||
f5a5ca79 | 2602 | rwco->ret = bdrv_co_pdiscard(rwco->bs, rwco->offset, rwco->bytes); |
61007b31 SH |
2603 | } |
2604 | ||
9f1963b3 | 2605 | int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, |
f5a5ca79 | 2606 | int bytes) |
61007b31 | 2607 | { |
b1066c87 | 2608 | BdrvTrackedRequest req; |
9f1963b3 | 2609 | int max_pdiscard, ret; |
3482b9bc | 2610 | int head, tail, align; |
61007b31 SH |
2611 | |
2612 | if (!bs->drv) { | |
2613 | return -ENOMEDIUM; | |
2614 | } | |
2615 | ||
d6883bc9 VSO |
2616 | if (bdrv_has_readonly_bitmaps(bs)) { |
2617 | return -EPERM; | |
2618 | } | |
2619 | ||
f5a5ca79 | 2620 | ret = bdrv_check_byte_request(bs, offset, bytes); |
61007b31 SH |
2621 | if (ret < 0) { |
2622 | return ret; | |
2623 | } else if (bs->read_only) { | |
eaf5fe2d | 2624 | return -EPERM; |
61007b31 | 2625 | } |
04c01a5c | 2626 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); |
61007b31 | 2627 | |
61007b31 SH |
2628 | /* Do nothing if disabled. */ |
2629 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
2630 | return 0; | |
2631 | } | |
2632 | ||
02aefe43 | 2633 | if (!bs->drv->bdrv_co_pdiscard && !bs->drv->bdrv_aio_pdiscard) { |
61007b31 SH |
2634 | return 0; |
2635 | } | |
2636 | ||
3482b9bc EB |
2637 | /* Discard is advisory, but some devices track and coalesce |
2638 | * unaligned requests, so we must pass everything down rather than | |
2639 | * round here. Still, most devices will just silently ignore | |
2640 | * unaligned requests (by returning -ENOTSUP), so we must fragment | |
2641 | * the request accordingly. */ | |
02aefe43 | 2642 | align = MAX(bs->bl.pdiscard_alignment, bs->bl.request_alignment); |
b8d0a980 EB |
2643 | assert(align % bs->bl.request_alignment == 0); |
2644 | head = offset % align; | |
f5a5ca79 | 2645 | tail = (offset + bytes) % align; |
9f1963b3 | 2646 | |
99723548 | 2647 | bdrv_inc_in_flight(bs); |
f5a5ca79 | 2648 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_DISCARD); |
50824995 | 2649 | |
ec050f77 DL |
2650 | ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); |
2651 | if (ret < 0) { | |
2652 | goto out; | |
2653 | } | |
2654 | ||
9f1963b3 EB |
2655 | max_pdiscard = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_pdiscard, INT_MAX), |
2656 | align); | |
3482b9bc | 2657 | assert(max_pdiscard >= bs->bl.request_alignment); |
61007b31 | 2658 | |
f5a5ca79 | 2659 | while (bytes > 0) { |
f5a5ca79 | 2660 | int num = bytes; |
3482b9bc EB |
2661 | |
2662 | if (head) { | |
2663 | /* Make small requests to get to alignment boundaries. */ | |
f5a5ca79 | 2664 | num = MIN(bytes, align - head); |
3482b9bc EB |
2665 | if (!QEMU_IS_ALIGNED(num, bs->bl.request_alignment)) { |
2666 | num %= bs->bl.request_alignment; | |
2667 | } | |
2668 | head = (head + num) % align; | |
2669 | assert(num < max_pdiscard); | |
2670 | } else if (tail) { | |
2671 | if (num > align) { | |
2672 | /* Shorten the request to the last aligned cluster. */ | |
2673 | num -= tail; | |
2674 | } else if (!QEMU_IS_ALIGNED(tail, bs->bl.request_alignment) && | |
2675 | tail > bs->bl.request_alignment) { | |
2676 | tail %= bs->bl.request_alignment; | |
2677 | num -= tail; | |
2678 | } | |
2679 | } | |
2680 | /* limit request size */ | |
2681 | if (num > max_pdiscard) { | |
2682 | num = max_pdiscard; | |
2683 | } | |
61007b31 | 2684 | |
d470ad42 HR |
2685 | if (!bs->drv) { |
2686 | ret = -ENOMEDIUM; | |
2687 | goto out; | |
2688 | } | |
47a5486d EB |
2689 | if (bs->drv->bdrv_co_pdiscard) { |
2690 | ret = bs->drv->bdrv_co_pdiscard(bs, offset, num); | |
61007b31 SH |
2691 | } else { |
2692 | BlockAIOCB *acb; | |
2693 | CoroutineIOCompletion co = { | |
2694 | .coroutine = qemu_coroutine_self(), | |
2695 | }; | |
2696 | ||
4da444a0 EB |
2697 | acb = bs->drv->bdrv_aio_pdiscard(bs, offset, num, |
2698 | bdrv_co_io_em_complete, &co); | |
61007b31 | 2699 | if (acb == NULL) { |
b1066c87 FZ |
2700 | ret = -EIO; |
2701 | goto out; | |
61007b31 SH |
2702 | } else { |
2703 | qemu_coroutine_yield(); | |
2704 | ret = co.ret; | |
2705 | } | |
2706 | } | |
2707 | if (ret && ret != -ENOTSUP) { | |
b1066c87 | 2708 | goto out; |
61007b31 SH |
2709 | } |
2710 | ||
9f1963b3 | 2711 | offset += num; |
f5a5ca79 | 2712 | bytes -= num; |
61007b31 | 2713 | } |
b1066c87 FZ |
2714 | ret = 0; |
2715 | out: | |
47fec599 | 2716 | atomic_inc(&bs->write_gen); |
0fdf1a4f | 2717 | bdrv_set_dirty(bs, req.offset, req.bytes); |
b1066c87 | 2718 | tracked_request_end(&req); |
99723548 | 2719 | bdrv_dec_in_flight(bs); |
b1066c87 | 2720 | return ret; |
61007b31 SH |
2721 | } |
2722 | ||
f5a5ca79 | 2723 | int bdrv_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) |
61007b31 SH |
2724 | { |
2725 | Coroutine *co; | |
2726 | DiscardCo rwco = { | |
2727 | .bs = bs, | |
0c51a893 | 2728 | .offset = offset, |
f5a5ca79 | 2729 | .bytes = bytes, |
61007b31 SH |
2730 | .ret = NOT_DONE, |
2731 | }; | |
2732 | ||
2733 | if (qemu_in_coroutine()) { | |
2734 | /* Fast-path if already in coroutine context */ | |
0c51a893 | 2735 | bdrv_pdiscard_co_entry(&rwco); |
61007b31 | 2736 | } else { |
0c51a893 | 2737 | co = qemu_coroutine_create(bdrv_pdiscard_co_entry, &rwco); |
e92f0e19 | 2738 | bdrv_coroutine_enter(bs, co); |
88b062c2 | 2739 | BDRV_POLL_WHILE(bs, rwco.ret == NOT_DONE); |
61007b31 SH |
2740 | } |
2741 | ||
2742 | return rwco.ret; | |
2743 | } | |
2744 | ||
48af776a | 2745 | int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf) |
61007b31 SH |
2746 | { |
2747 | BlockDriver *drv = bs->drv; | |
5c5ae76a FZ |
2748 | CoroutineIOCompletion co = { |
2749 | .coroutine = qemu_coroutine_self(), | |
2750 | }; | |
2751 | BlockAIOCB *acb; | |
61007b31 | 2752 | |
99723548 | 2753 | bdrv_inc_in_flight(bs); |
16a389dc | 2754 | if (!drv || (!drv->bdrv_aio_ioctl && !drv->bdrv_co_ioctl)) { |
5c5ae76a FZ |
2755 | co.ret = -ENOTSUP; |
2756 | goto out; | |
2757 | } | |
2758 | ||
16a389dc KW |
2759 | if (drv->bdrv_co_ioctl) { |
2760 | co.ret = drv->bdrv_co_ioctl(bs, req, buf); | |
2761 | } else { | |
2762 | acb = drv->bdrv_aio_ioctl(bs, req, buf, bdrv_co_io_em_complete, &co); | |
2763 | if (!acb) { | |
2764 | co.ret = -ENOTSUP; | |
2765 | goto out; | |
2766 | } | |
2767 | qemu_coroutine_yield(); | |
5c5ae76a | 2768 | } |
5c5ae76a | 2769 | out: |
99723548 | 2770 | bdrv_dec_in_flight(bs); |
5c5ae76a FZ |
2771 | return co.ret; |
2772 | } | |
2773 | ||
61007b31 SH |
2774 | void *qemu_blockalign(BlockDriverState *bs, size_t size) |
2775 | { | |
2776 | return qemu_memalign(bdrv_opt_mem_align(bs), size); | |
2777 | } | |
2778 | ||
2779 | void *qemu_blockalign0(BlockDriverState *bs, size_t size) | |
2780 | { | |
2781 | return memset(qemu_blockalign(bs, size), 0, size); | |
2782 | } | |
2783 | ||
2784 | void *qemu_try_blockalign(BlockDriverState *bs, size_t size) | |
2785 | { | |
2786 | size_t align = bdrv_opt_mem_align(bs); | |
2787 | ||
2788 | /* Ensure that NULL is never returned on success */ | |
2789 | assert(align > 0); | |
2790 | if (size == 0) { | |
2791 | size = align; | |
2792 | } | |
2793 | ||
2794 | return qemu_try_memalign(align, size); | |
2795 | } | |
2796 | ||
2797 | void *qemu_try_blockalign0(BlockDriverState *bs, size_t size) | |
2798 | { | |
2799 | void *mem = qemu_try_blockalign(bs, size); | |
2800 | ||
2801 | if (mem) { | |
2802 | memset(mem, 0, size); | |
2803 | } | |
2804 | ||
2805 | return mem; | |
2806 | } | |
2807 | ||
2808 | /* | |
2809 | * Check if all memory in this vector is sector aligned. | |
2810 | */ | |
2811 | bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) | |
2812 | { | |
2813 | int i; | |
4196d2f0 | 2814 | size_t alignment = bdrv_min_mem_align(bs); |
61007b31 SH |
2815 | |
2816 | for (i = 0; i < qiov->niov; i++) { | |
2817 | if ((uintptr_t) qiov->iov[i].iov_base % alignment) { | |
2818 | return false; | |
2819 | } | |
2820 | if (qiov->iov[i].iov_len % alignment) { | |
2821 | return false; | |
2822 | } | |
2823 | } | |
2824 | ||
2825 | return true; | |
2826 | } | |
2827 | ||
2828 | void bdrv_add_before_write_notifier(BlockDriverState *bs, | |
2829 | NotifierWithReturn *notifier) | |
2830 | { | |
2831 | notifier_with_return_list_add(&bs->before_write_notifiers, notifier); | |
2832 | } | |
2833 | ||
2834 | void bdrv_io_plug(BlockDriverState *bs) | |
2835 | { | |
6b98bd64 PB |
2836 | BdrvChild *child; |
2837 | ||
2838 | QLIST_FOREACH(child, &bs->children, next) { | |
2839 | bdrv_io_plug(child->bs); | |
2840 | } | |
2841 | ||
850d54a2 | 2842 | if (atomic_fetch_inc(&bs->io_plugged) == 0) { |
6b98bd64 PB |
2843 | BlockDriver *drv = bs->drv; |
2844 | if (drv && drv->bdrv_io_plug) { | |
2845 | drv->bdrv_io_plug(bs); | |
2846 | } | |
61007b31 SH |
2847 | } |
2848 | } | |
2849 | ||
2850 | void bdrv_io_unplug(BlockDriverState *bs) | |
2851 | { | |
6b98bd64 PB |
2852 | BdrvChild *child; |
2853 | ||
2854 | assert(bs->io_plugged); | |
850d54a2 | 2855 | if (atomic_fetch_dec(&bs->io_plugged) == 1) { |
6b98bd64 PB |
2856 | BlockDriver *drv = bs->drv; |
2857 | if (drv && drv->bdrv_io_unplug) { | |
2858 | drv->bdrv_io_unplug(bs); | |
2859 | } | |
2860 | } | |
2861 | ||
2862 | QLIST_FOREACH(child, &bs->children, next) { | |
2863 | bdrv_io_unplug(child->bs); | |
61007b31 SH |
2864 | } |
2865 | } | |
23d0ba93 FZ |
2866 | |
2867 | void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size) | |
2868 | { | |
2869 | BdrvChild *child; | |
2870 | ||
2871 | if (bs->drv && bs->drv->bdrv_register_buf) { | |
2872 | bs->drv->bdrv_register_buf(bs, host, size); | |
2873 | } | |
2874 | QLIST_FOREACH(child, &bs->children, next) { | |
2875 | bdrv_register_buf(child->bs, host, size); | |
2876 | } | |
2877 | } | |
2878 | ||
2879 | void bdrv_unregister_buf(BlockDriverState *bs, void *host) | |
2880 | { | |
2881 | BdrvChild *child; | |
2882 | ||
2883 | if (bs->drv && bs->drv->bdrv_unregister_buf) { | |
2884 | bs->drv->bdrv_unregister_buf(bs, host); | |
2885 | } | |
2886 | QLIST_FOREACH(child, &bs->children, next) { | |
2887 | bdrv_unregister_buf(child->bs, host); | |
2888 | } | |
2889 | } | |
fcc67678 FZ |
2890 | |
2891 | static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src, | |
2892 | uint64_t src_offset, | |
2893 | BdrvChild *dst, | |
2894 | uint64_t dst_offset, | |
2895 | uint64_t bytes, | |
2896 | BdrvRequestFlags flags, | |
2897 | bool recurse_src) | |
2898 | { | |
37aec7d7 | 2899 | BdrvTrackedRequest src_req, dst_req; |
fcc67678 FZ |
2900 | int ret; |
2901 | ||
d4d3e5a0 | 2902 | if (!dst || !dst->bs) { |
fcc67678 FZ |
2903 | return -ENOMEDIUM; |
2904 | } | |
fcc67678 FZ |
2905 | ret = bdrv_check_byte_request(dst->bs, dst_offset, bytes); |
2906 | if (ret) { | |
2907 | return ret; | |
2908 | } | |
2909 | if (flags & BDRV_REQ_ZERO_WRITE) { | |
2910 | return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, flags); | |
2911 | } | |
2912 | ||
d4d3e5a0 FZ |
2913 | if (!src || !src->bs) { |
2914 | return -ENOMEDIUM; | |
2915 | } | |
2916 | ret = bdrv_check_byte_request(src->bs, src_offset, bytes); | |
2917 | if (ret) { | |
2918 | return ret; | |
2919 | } | |
2920 | ||
fcc67678 FZ |
2921 | if (!src->bs->drv->bdrv_co_copy_range_from |
2922 | || !dst->bs->drv->bdrv_co_copy_range_to | |
2923 | || src->bs->encrypted || dst->bs->encrypted) { | |
2924 | return -ENOTSUP; | |
2925 | } | |
d4d3e5a0 FZ |
2926 | bdrv_inc_in_flight(src->bs); |
2927 | bdrv_inc_in_flight(dst->bs); | |
2928 | tracked_request_begin(&src_req, src->bs, src_offset, | |
37aec7d7 | 2929 | bytes, BDRV_TRACKED_READ); |
d4d3e5a0 | 2930 | tracked_request_begin(&dst_req, dst->bs, dst_offset, |
37aec7d7 FZ |
2931 | bytes, BDRV_TRACKED_WRITE); |
2932 | ||
dee12de8 FZ |
2933 | if (!(flags & BDRV_REQ_NO_SERIALISING)) { |
2934 | wait_serialising_requests(&src_req); | |
2935 | wait_serialising_requests(&dst_req); | |
2936 | } | |
fcc67678 | 2937 | if (recurse_src) { |
37aec7d7 FZ |
2938 | ret = src->bs->drv->bdrv_co_copy_range_from(src->bs, |
2939 | src, src_offset, | |
2940 | dst, dst_offset, | |
2941 | bytes, flags); | |
fcc67678 | 2942 | } else { |
37aec7d7 FZ |
2943 | ret = dst->bs->drv->bdrv_co_copy_range_to(dst->bs, |
2944 | src, src_offset, | |
2945 | dst, dst_offset, | |
2946 | bytes, flags); | |
fcc67678 | 2947 | } |
37aec7d7 FZ |
2948 | tracked_request_end(&src_req); |
2949 | tracked_request_end(&dst_req); | |
d4d3e5a0 FZ |
2950 | bdrv_dec_in_flight(src->bs); |
2951 | bdrv_dec_in_flight(dst->bs); | |
37aec7d7 | 2952 | return ret; |
fcc67678 FZ |
2953 | } |
2954 | ||
2955 | /* Copy range from @src to @dst. | |
2956 | * | |
2957 | * See the comment of bdrv_co_copy_range for the parameter and return value | |
2958 | * semantics. */ | |
2959 | int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset, | |
2960 | BdrvChild *dst, uint64_t dst_offset, | |
2961 | uint64_t bytes, BdrvRequestFlags flags) | |
2962 | { | |
2963 | return bdrv_co_copy_range_internal(src, src_offset, dst, dst_offset, | |
2964 | bytes, flags, true); | |
2965 | } | |
2966 | ||
2967 | /* Copy range from @src to @dst. | |
2968 | * | |
2969 | * See the comment of bdrv_co_copy_range for the parameter and return value | |
2970 | * semantics. */ | |
2971 | int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset, | |
2972 | BdrvChild *dst, uint64_t dst_offset, | |
2973 | uint64_t bytes, BdrvRequestFlags flags) | |
2974 | { | |
2975 | return bdrv_co_copy_range_internal(src, src_offset, dst, dst_offset, | |
2976 | bytes, flags, false); | |
2977 | } | |
2978 | ||
2979 | int coroutine_fn bdrv_co_copy_range(BdrvChild *src, uint64_t src_offset, | |
2980 | BdrvChild *dst, uint64_t dst_offset, | |
2981 | uint64_t bytes, BdrvRequestFlags flags) | |
2982 | { | |
37aec7d7 FZ |
2983 | return bdrv_co_copy_range_from(src, src_offset, |
2984 | dst, dst_offset, | |
2985 | bytes, flags); | |
fcc67678 | 2986 | } |
3d9f2d2a KW |
2987 | |
2988 | static void bdrv_parent_cb_resize(BlockDriverState *bs) | |
2989 | { | |
2990 | BdrvChild *c; | |
2991 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
2992 | if (c->role->resize) { | |
2993 | c->role->resize(c); | |
2994 | } | |
2995 | } | |
2996 | } | |
2997 | ||
2998 | /** | |
2999 | * Truncate file to 'offset' bytes (needed only for file protocols) | |
3000 | */ | |
3001 | int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, | |
3002 | PreallocMode prealloc, Error **errp) | |
3003 | { | |
3004 | BlockDriverState *bs = child->bs; | |
3005 | BlockDriver *drv = bs->drv; | |
1bc5f09f KW |
3006 | BdrvTrackedRequest req; |
3007 | int64_t old_size, new_bytes; | |
3d9f2d2a KW |
3008 | int ret; |
3009 | ||
3010 | assert(child->perm & BLK_PERM_RESIZE); | |
3011 | ||
3012 | /* if bs->drv == NULL, bs is closed, so there's nothing to do here */ | |
3013 | if (!drv) { | |
3014 | error_setg(errp, "No medium inserted"); | |
3015 | return -ENOMEDIUM; | |
3016 | } | |
3017 | if (offset < 0) { | |
3018 | error_setg(errp, "Image size cannot be negative"); | |
3019 | return -EINVAL; | |
3020 | } | |
3021 | ||
1bc5f09f KW |
3022 | old_size = bdrv_getlength(bs); |
3023 | if (old_size < 0) { | |
3024 | error_setg_errno(errp, -old_size, "Failed to get old image size"); | |
3025 | return old_size; | |
3026 | } | |
3027 | ||
3028 | if (offset > old_size) { | |
3029 | new_bytes = offset - old_size; | |
3030 | } else { | |
3031 | new_bytes = 0; | |
3032 | } | |
3033 | ||
3d9f2d2a | 3034 | bdrv_inc_in_flight(bs); |
1bc5f09f KW |
3035 | tracked_request_begin(&req, bs, offset, new_bytes, BDRV_TRACKED_TRUNCATE); |
3036 | ||
3037 | /* If we are growing the image and potentially using preallocation for the | |
3038 | * new area, we need to make sure that no write requests are made to it | |
3039 | * concurrently or they might be overwritten by preallocation. */ | |
3040 | if (new_bytes) { | |
3041 | mark_request_serialising(&req, 1); | |
3042 | wait_serialising_requests(&req); | |
3043 | } | |
3d9f2d2a KW |
3044 | |
3045 | if (!drv->bdrv_co_truncate) { | |
3046 | if (bs->file && drv->is_filter) { | |
3047 | ret = bdrv_co_truncate(bs->file, offset, prealloc, errp); | |
3048 | goto out; | |
3049 | } | |
3050 | error_setg(errp, "Image format driver does not support resize"); | |
3051 | ret = -ENOTSUP; | |
3052 | goto out; | |
3053 | } | |
3054 | if (bs->read_only) { | |
3055 | error_setg(errp, "Image is read-only"); | |
3056 | ret = -EACCES; | |
3057 | goto out; | |
3058 | } | |
3059 | ||
3060 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); | |
3061 | ||
3062 | ret = drv->bdrv_co_truncate(bs, offset, prealloc, errp); | |
3063 | if (ret < 0) { | |
3064 | goto out; | |
3065 | } | |
3066 | ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); | |
3067 | if (ret < 0) { | |
3068 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
3069 | } else { | |
3070 | offset = bs->total_sectors * BDRV_SECTOR_SIZE; | |
3071 | } | |
3072 | bdrv_dirty_bitmap_truncate(bs, offset); | |
3073 | bdrv_parent_cb_resize(bs); | |
3074 | atomic_inc(&bs->write_gen); | |
3075 | ||
3076 | out: | |
1bc5f09f | 3077 | tracked_request_end(&req); |
3d9f2d2a | 3078 | bdrv_dec_in_flight(bs); |
1bc5f09f | 3079 | |
3d9f2d2a KW |
3080 | return ret; |
3081 | } | |
3082 | ||
3083 | typedef struct TruncateCo { | |
3084 | BdrvChild *child; | |
3085 | int64_t offset; | |
3086 | PreallocMode prealloc; | |
3087 | Error **errp; | |
3088 | int ret; | |
3089 | } TruncateCo; | |
3090 | ||
3091 | static void coroutine_fn bdrv_truncate_co_entry(void *opaque) | |
3092 | { | |
3093 | TruncateCo *tco = opaque; | |
3094 | tco->ret = bdrv_co_truncate(tco->child, tco->offset, tco->prealloc, | |
3095 | tco->errp); | |
3096 | } | |
3097 | ||
3098 | int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc, | |
3099 | Error **errp) | |
3100 | { | |
3101 | Coroutine *co; | |
3102 | TruncateCo tco = { | |
3103 | .child = child, | |
3104 | .offset = offset, | |
3105 | .prealloc = prealloc, | |
3106 | .errp = errp, | |
3107 | .ret = NOT_DONE, | |
3108 | }; | |
3109 | ||
3110 | if (qemu_in_coroutine()) { | |
3111 | /* Fast-path if already in coroutine context */ | |
3112 | bdrv_truncate_co_entry(&tco); | |
3113 | } else { | |
3114 | co = qemu_coroutine_create(bdrv_truncate_co_entry, &tco); | |
3115 | qemu_coroutine_enter(co); | |
3116 | BDRV_POLL_WHILE(child->bs, tco.ret == NOT_DONE); | |
3117 | } | |
3118 | ||
3119 | return tco.ret; | |
3120 | } |