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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" |
21c2283e | 32 | #include "block/coroutines.h" |
94783301 | 33 | #include "block/write-threshold.h" |
f348b6d1 | 34 | #include "qemu/cutils.h" |
da34e65c | 35 | #include "qapi/error.h" |
d49b6836 | 36 | #include "qemu/error-report.h" |
db725815 | 37 | #include "qemu/main-loop.h" |
c8aa7895 | 38 | #include "sysemu/replay.h" |
61007b31 | 39 | |
cb2e2878 EB |
40 | /* Maximum bounce buffer for copy-on-read and write zeroes, in bytes */ |
41 | #define MAX_BOUNCE_BUFFER (32768 << BDRV_SECTOR_BITS) | |
42 | ||
7f8f03ef | 43 | static void bdrv_parent_cb_resize(BlockDriverState *bs); |
d05aa8bb | 44 | static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, |
5ae07b14 | 45 | int64_t offset, int64_t bytes, BdrvRequestFlags flags); |
61007b31 | 46 | |
f4c8a43b HR |
47 | static void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore, |
48 | bool ignore_bds_parents) | |
61007b31 | 49 | { |
02d21300 | 50 | BdrvChild *c, *next; |
27ccdd52 | 51 | |
02d21300 | 52 | QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) { |
bd86fb99 | 53 | if (c == ignore || (ignore_bds_parents && c->klass->parent_is_bds)) { |
0152bf40 KW |
54 | continue; |
55 | } | |
4be6a6d1 | 56 | bdrv_parent_drained_begin_single(c, false); |
ce0f1412 PB |
57 | } |
58 | } | |
61007b31 | 59 | |
e037c09c HR |
60 | static void bdrv_parent_drained_end_single_no_poll(BdrvChild *c, |
61 | int *drained_end_counter) | |
804db8ea HR |
62 | { |
63 | assert(c->parent_quiesce_counter > 0); | |
64 | c->parent_quiesce_counter--; | |
bd86fb99 HR |
65 | if (c->klass->drained_end) { |
66 | c->klass->drained_end(c, drained_end_counter); | |
804db8ea HR |
67 | } |
68 | } | |
69 | ||
e037c09c HR |
70 | void bdrv_parent_drained_end_single(BdrvChild *c) |
71 | { | |
72 | int drained_end_counter = 0; | |
73 | bdrv_parent_drained_end_single_no_poll(c, &drained_end_counter); | |
d73415a3 | 74 | BDRV_POLL_WHILE(c->bs, qatomic_read(&drained_end_counter) > 0); |
e037c09c HR |
75 | } |
76 | ||
f4c8a43b | 77 | static void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore, |
e037c09c HR |
78 | bool ignore_bds_parents, |
79 | int *drained_end_counter) | |
ce0f1412 | 80 | { |
61ad631c | 81 | BdrvChild *c; |
27ccdd52 | 82 | |
61ad631c | 83 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
bd86fb99 | 84 | if (c == ignore || (ignore_bds_parents && c->klass->parent_is_bds)) { |
0152bf40 KW |
85 | continue; |
86 | } | |
e037c09c | 87 | bdrv_parent_drained_end_single_no_poll(c, drained_end_counter); |
27ccdd52 | 88 | } |
61007b31 SH |
89 | } |
90 | ||
4be6a6d1 KW |
91 | static bool bdrv_parent_drained_poll_single(BdrvChild *c) |
92 | { | |
bd86fb99 HR |
93 | if (c->klass->drained_poll) { |
94 | return c->klass->drained_poll(c); | |
4be6a6d1 KW |
95 | } |
96 | return false; | |
97 | } | |
98 | ||
6cd5c9d7 KW |
99 | static bool bdrv_parent_drained_poll(BlockDriverState *bs, BdrvChild *ignore, |
100 | bool ignore_bds_parents) | |
89bd0305 KW |
101 | { |
102 | BdrvChild *c, *next; | |
103 | bool busy = false; | |
104 | ||
105 | QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) { | |
bd86fb99 | 106 | if (c == ignore || (ignore_bds_parents && c->klass->parent_is_bds)) { |
89bd0305 KW |
107 | continue; |
108 | } | |
4be6a6d1 | 109 | busy |= bdrv_parent_drained_poll_single(c); |
89bd0305 KW |
110 | } |
111 | ||
112 | return busy; | |
113 | } | |
114 | ||
4be6a6d1 KW |
115 | void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll) |
116 | { | |
804db8ea | 117 | c->parent_quiesce_counter++; |
bd86fb99 HR |
118 | if (c->klass->drained_begin) { |
119 | c->klass->drained_begin(c); | |
4be6a6d1 KW |
120 | } |
121 | if (poll) { | |
122 | BDRV_POLL_WHILE(c->bs, bdrv_parent_drained_poll_single(c)); | |
123 | } | |
124 | } | |
125 | ||
d9e0dfa2 EB |
126 | static void bdrv_merge_limits(BlockLimits *dst, const BlockLimits *src) |
127 | { | |
9f460c64 AO |
128 | dst->pdiscard_alignment = MAX(dst->pdiscard_alignment, |
129 | src->pdiscard_alignment); | |
d9e0dfa2 EB |
130 | dst->opt_transfer = MAX(dst->opt_transfer, src->opt_transfer); |
131 | dst->max_transfer = MIN_NON_ZERO(dst->max_transfer, src->max_transfer); | |
24b36e98 PB |
132 | dst->max_hw_transfer = MIN_NON_ZERO(dst->max_hw_transfer, |
133 | src->max_hw_transfer); | |
d9e0dfa2 EB |
134 | dst->opt_mem_alignment = MAX(dst->opt_mem_alignment, |
135 | src->opt_mem_alignment); | |
136 | dst->min_mem_alignment = MAX(dst->min_mem_alignment, | |
137 | src->min_mem_alignment); | |
138 | dst->max_iov = MIN_NON_ZERO(dst->max_iov, src->max_iov); | |
cc071629 | 139 | dst->max_hw_iov = MIN_NON_ZERO(dst->max_hw_iov, src->max_hw_iov); |
d9e0dfa2 EB |
140 | } |
141 | ||
1e4c797c VSO |
142 | typedef struct BdrvRefreshLimitsState { |
143 | BlockDriverState *bs; | |
144 | BlockLimits old_bl; | |
145 | } BdrvRefreshLimitsState; | |
146 | ||
147 | static void bdrv_refresh_limits_abort(void *opaque) | |
148 | { | |
149 | BdrvRefreshLimitsState *s = opaque; | |
150 | ||
151 | s->bs->bl = s->old_bl; | |
152 | } | |
153 | ||
154 | static TransactionActionDrv bdrv_refresh_limits_drv = { | |
155 | .abort = bdrv_refresh_limits_abort, | |
156 | .clean = g_free, | |
157 | }; | |
158 | ||
159 | /* @tran is allowed to be NULL, in this case no rollback is possible. */ | |
160 | void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp) | |
61007b31 | 161 | { |
33985614 | 162 | ERRP_GUARD(); |
61007b31 | 163 | BlockDriver *drv = bs->drv; |
66b129ac HR |
164 | BdrvChild *c; |
165 | bool have_limits; | |
61007b31 | 166 | |
1e4c797c VSO |
167 | if (tran) { |
168 | BdrvRefreshLimitsState *s = g_new(BdrvRefreshLimitsState, 1); | |
169 | *s = (BdrvRefreshLimitsState) { | |
170 | .bs = bs, | |
171 | .old_bl = bs->bl, | |
172 | }; | |
173 | tran_add(tran, &bdrv_refresh_limits_drv, s); | |
174 | } | |
175 | ||
61007b31 SH |
176 | memset(&bs->bl, 0, sizeof(bs->bl)); |
177 | ||
178 | if (!drv) { | |
179 | return; | |
180 | } | |
181 | ||
79ba8c98 | 182 | /* Default alignment based on whether driver has byte interface */ |
e31f6864 | 183 | bs->bl.request_alignment = (drv->bdrv_co_preadv || |
ac850bf0 VSO |
184 | drv->bdrv_aio_preadv || |
185 | drv->bdrv_co_preadv_part) ? 1 : 512; | |
79ba8c98 | 186 | |
61007b31 | 187 | /* Take some limits from the children as a default */ |
66b129ac HR |
188 | have_limits = false; |
189 | QLIST_FOREACH(c, &bs->children, next) { | |
190 | if (c->role & (BDRV_CHILD_DATA | BDRV_CHILD_FILTERED | BDRV_CHILD_COW)) | |
191 | { | |
1e4c797c | 192 | bdrv_refresh_limits(c->bs, tran, errp); |
33985614 | 193 | if (*errp) { |
66b129ac HR |
194 | return; |
195 | } | |
196 | bdrv_merge_limits(&bs->bl, &c->bs->bl); | |
197 | have_limits = true; | |
61007b31 | 198 | } |
66b129ac HR |
199 | } |
200 | ||
201 | if (!have_limits) { | |
4196d2f0 | 202 | bs->bl.min_mem_alignment = 512; |
038adc2f | 203 | bs->bl.opt_mem_alignment = qemu_real_host_page_size; |
bd44feb7 SH |
204 | |
205 | /* Safe default since most protocols use readv()/writev()/etc */ | |
206 | bs->bl.max_iov = IOV_MAX; | |
61007b31 SH |
207 | } |
208 | ||
61007b31 SH |
209 | /* Then let the driver override it */ |
210 | if (drv->bdrv_refresh_limits) { | |
211 | drv->bdrv_refresh_limits(bs, errp); | |
8b117001 VSO |
212 | if (*errp) { |
213 | return; | |
214 | } | |
215 | } | |
216 | ||
217 | if (bs->bl.request_alignment > BDRV_MAX_ALIGNMENT) { | |
218 | error_setg(errp, "Driver requires too large request alignment"); | |
61007b31 SH |
219 | } |
220 | } | |
221 | ||
222 | /** | |
223 | * The copy-on-read flag is actually a reference count so multiple users may | |
224 | * use the feature without worrying about clobbering its previous state. | |
225 | * Copy-on-read stays enabled until all users have called to disable it. | |
226 | */ | |
227 | void bdrv_enable_copy_on_read(BlockDriverState *bs) | |
228 | { | |
d73415a3 | 229 | qatomic_inc(&bs->copy_on_read); |
61007b31 SH |
230 | } |
231 | ||
232 | void bdrv_disable_copy_on_read(BlockDriverState *bs) | |
233 | { | |
d73415a3 | 234 | int old = qatomic_fetch_dec(&bs->copy_on_read); |
d3faa13e | 235 | assert(old >= 1); |
61007b31 SH |
236 | } |
237 | ||
61124f03 PB |
238 | typedef struct { |
239 | Coroutine *co; | |
240 | BlockDriverState *bs; | |
241 | bool done; | |
481cad48 | 242 | bool begin; |
b0165585 | 243 | bool recursive; |
fe4f0614 | 244 | bool poll; |
0152bf40 | 245 | BdrvChild *parent; |
6cd5c9d7 | 246 | bool ignore_bds_parents; |
8e1da77e | 247 | int *drained_end_counter; |
61124f03 PB |
248 | } BdrvCoDrainData; |
249 | ||
250 | static void coroutine_fn bdrv_drain_invoke_entry(void *opaque) | |
251 | { | |
252 | BdrvCoDrainData *data = opaque; | |
253 | BlockDriverState *bs = data->bs; | |
254 | ||
481cad48 | 255 | if (data->begin) { |
f8ea8dac | 256 | bs->drv->bdrv_co_drain_begin(bs); |
481cad48 MP |
257 | } else { |
258 | bs->drv->bdrv_co_drain_end(bs); | |
259 | } | |
61124f03 | 260 | |
65181d63 | 261 | /* Set data->done and decrement drained_end_counter before bdrv_wakeup() */ |
d73415a3 | 262 | qatomic_mb_set(&data->done, true); |
e037c09c | 263 | if (!data->begin) { |
d73415a3 | 264 | qatomic_dec(data->drained_end_counter); |
8e1da77e | 265 | } |
65181d63 | 266 | bdrv_dec_in_flight(bs); |
8e1da77e | 267 | |
e037c09c | 268 | g_free(data); |
61124f03 PB |
269 | } |
270 | ||
db0289b9 | 271 | /* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */ |
8e1da77e HR |
272 | static void bdrv_drain_invoke(BlockDriverState *bs, bool begin, |
273 | int *drained_end_counter) | |
61124f03 | 274 | { |
0109e7e6 | 275 | BdrvCoDrainData *data; |
61124f03 | 276 | |
f8ea8dac | 277 | if (!bs->drv || (begin && !bs->drv->bdrv_co_drain_begin) || |
481cad48 | 278 | (!begin && !bs->drv->bdrv_co_drain_end)) { |
61124f03 PB |
279 | return; |
280 | } | |
281 | ||
0109e7e6 KW |
282 | data = g_new(BdrvCoDrainData, 1); |
283 | *data = (BdrvCoDrainData) { | |
284 | .bs = bs, | |
285 | .done = false, | |
8e1da77e HR |
286 | .begin = begin, |
287 | .drained_end_counter = drained_end_counter, | |
0109e7e6 KW |
288 | }; |
289 | ||
e037c09c | 290 | if (!begin) { |
d73415a3 | 291 | qatomic_inc(drained_end_counter); |
8e1da77e HR |
292 | } |
293 | ||
0109e7e6 KW |
294 | /* Make sure the driver callback completes during the polling phase for |
295 | * drain_begin. */ | |
296 | bdrv_inc_in_flight(bs); | |
297 | data->co = qemu_coroutine_create(bdrv_drain_invoke_entry, data); | |
298 | aio_co_schedule(bdrv_get_aio_context(bs), data->co); | |
61124f03 PB |
299 | } |
300 | ||
1cc8e54a | 301 | /* Returns true if BDRV_POLL_WHILE() should go into a blocking aio_poll() */ |
fe4f0614 | 302 | bool bdrv_drain_poll(BlockDriverState *bs, bool recursive, |
6cd5c9d7 | 303 | BdrvChild *ignore_parent, bool ignore_bds_parents) |
89bd0305 | 304 | { |
fe4f0614 KW |
305 | BdrvChild *child, *next; |
306 | ||
6cd5c9d7 | 307 | if (bdrv_parent_drained_poll(bs, ignore_parent, ignore_bds_parents)) { |
89bd0305 KW |
308 | return true; |
309 | } | |
310 | ||
d73415a3 | 311 | if (qatomic_read(&bs->in_flight)) { |
fe4f0614 KW |
312 | return true; |
313 | } | |
314 | ||
315 | if (recursive) { | |
6cd5c9d7 | 316 | assert(!ignore_bds_parents); |
fe4f0614 | 317 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
6cd5c9d7 | 318 | if (bdrv_drain_poll(child->bs, recursive, child, false)) { |
fe4f0614 KW |
319 | return true; |
320 | } | |
321 | } | |
322 | } | |
323 | ||
324 | return false; | |
89bd0305 KW |
325 | } |
326 | ||
fe4f0614 | 327 | static bool bdrv_drain_poll_top_level(BlockDriverState *bs, bool recursive, |
89bd0305 | 328 | BdrvChild *ignore_parent) |
1cc8e54a | 329 | { |
6cd5c9d7 | 330 | return bdrv_drain_poll(bs, recursive, ignore_parent, false); |
1cc8e54a KW |
331 | } |
332 | ||
b0165585 | 333 | static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, |
6cd5c9d7 KW |
334 | BdrvChild *parent, bool ignore_bds_parents, |
335 | bool poll); | |
b0165585 | 336 | static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, |
8e1da77e HR |
337 | BdrvChild *parent, bool ignore_bds_parents, |
338 | int *drained_end_counter); | |
0152bf40 | 339 | |
a77fd4bb FZ |
340 | static void bdrv_co_drain_bh_cb(void *opaque) |
341 | { | |
342 | BdrvCoDrainData *data = opaque; | |
343 | Coroutine *co = data->co; | |
99723548 | 344 | BlockDriverState *bs = data->bs; |
a77fd4bb | 345 | |
c8ca33d0 | 346 | if (bs) { |
aa1361d5 | 347 | AioContext *ctx = bdrv_get_aio_context(bs); |
960d5fb3 | 348 | aio_context_acquire(ctx); |
c8ca33d0 KW |
349 | bdrv_dec_in_flight(bs); |
350 | if (data->begin) { | |
e037c09c | 351 | assert(!data->drained_end_counter); |
6cd5c9d7 KW |
352 | bdrv_do_drained_begin(bs, data->recursive, data->parent, |
353 | data->ignore_bds_parents, data->poll); | |
c8ca33d0 | 354 | } else { |
e037c09c | 355 | assert(!data->poll); |
6cd5c9d7 | 356 | bdrv_do_drained_end(bs, data->recursive, data->parent, |
8e1da77e HR |
357 | data->ignore_bds_parents, |
358 | data->drained_end_counter); | |
c8ca33d0 | 359 | } |
960d5fb3 | 360 | aio_context_release(ctx); |
481cad48 | 361 | } else { |
c8ca33d0 KW |
362 | assert(data->begin); |
363 | bdrv_drain_all_begin(); | |
481cad48 MP |
364 | } |
365 | ||
a77fd4bb | 366 | data->done = true; |
1919631e | 367 | aio_co_wake(co); |
a77fd4bb FZ |
368 | } |
369 | ||
481cad48 | 370 | static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, |
b0165585 | 371 | bool begin, bool recursive, |
6cd5c9d7 KW |
372 | BdrvChild *parent, |
373 | bool ignore_bds_parents, | |
8e1da77e HR |
374 | bool poll, |
375 | int *drained_end_counter) | |
a77fd4bb FZ |
376 | { |
377 | BdrvCoDrainData data; | |
960d5fb3 KW |
378 | Coroutine *self = qemu_coroutine_self(); |
379 | AioContext *ctx = bdrv_get_aio_context(bs); | |
380 | AioContext *co_ctx = qemu_coroutine_get_aio_context(self); | |
a77fd4bb FZ |
381 | |
382 | /* Calling bdrv_drain() from a BH ensures the current coroutine yields and | |
c40a2545 | 383 | * other coroutines run if they were queued by aio_co_enter(). */ |
a77fd4bb FZ |
384 | |
385 | assert(qemu_in_coroutine()); | |
386 | data = (BdrvCoDrainData) { | |
960d5fb3 | 387 | .co = self, |
a77fd4bb FZ |
388 | .bs = bs, |
389 | .done = false, | |
481cad48 | 390 | .begin = begin, |
b0165585 | 391 | .recursive = recursive, |
0152bf40 | 392 | .parent = parent, |
6cd5c9d7 | 393 | .ignore_bds_parents = ignore_bds_parents, |
fe4f0614 | 394 | .poll = poll, |
8e1da77e | 395 | .drained_end_counter = drained_end_counter, |
a77fd4bb | 396 | }; |
8e1da77e | 397 | |
c8ca33d0 KW |
398 | if (bs) { |
399 | bdrv_inc_in_flight(bs); | |
400 | } | |
960d5fb3 KW |
401 | |
402 | /* | |
403 | * Temporarily drop the lock across yield or we would get deadlocks. | |
404 | * bdrv_co_drain_bh_cb() reaquires the lock as needed. | |
405 | * | |
406 | * When we yield below, the lock for the current context will be | |
407 | * released, so if this is actually the lock that protects bs, don't drop | |
408 | * it a second time. | |
409 | */ | |
410 | if (ctx != co_ctx) { | |
411 | aio_context_release(ctx); | |
412 | } | |
413 | replay_bh_schedule_oneshot_event(ctx, bdrv_co_drain_bh_cb, &data); | |
a77fd4bb FZ |
414 | |
415 | qemu_coroutine_yield(); | |
416 | /* If we are resumed from some other event (such as an aio completion or a | |
417 | * timer callback), it is a bug in the caller that should be fixed. */ | |
418 | assert(data.done); | |
960d5fb3 KW |
419 | |
420 | /* Reaquire the AioContext of bs if we dropped it */ | |
421 | if (ctx != co_ctx) { | |
422 | aio_context_acquire(ctx); | |
423 | } | |
a77fd4bb FZ |
424 | } |
425 | ||
dcf94a23 | 426 | void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, |
6cd5c9d7 | 427 | BdrvChild *parent, bool ignore_bds_parents) |
6820643f | 428 | { |
dcf94a23 | 429 | assert(!qemu_in_coroutine()); |
d42cf288 | 430 | |
60369b86 | 431 | /* Stop things in parent-to-child order */ |
d73415a3 | 432 | if (qatomic_fetch_inc(&bs->quiesce_counter) == 0) { |
6820643f | 433 | aio_disable_external(bdrv_get_aio_context(bs)); |
6820643f KW |
434 | } |
435 | ||
6cd5c9d7 | 436 | bdrv_parent_drained_begin(bs, parent, ignore_bds_parents); |
8e1da77e | 437 | bdrv_drain_invoke(bs, true, NULL); |
dcf94a23 KW |
438 | } |
439 | ||
440 | static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, | |
6cd5c9d7 KW |
441 | BdrvChild *parent, bool ignore_bds_parents, |
442 | bool poll) | |
dcf94a23 KW |
443 | { |
444 | BdrvChild *child, *next; | |
445 | ||
446 | if (qemu_in_coroutine()) { | |
6cd5c9d7 | 447 | bdrv_co_yield_to_drain(bs, true, recursive, parent, ignore_bds_parents, |
8e1da77e | 448 | poll, NULL); |
dcf94a23 KW |
449 | return; |
450 | } | |
451 | ||
6cd5c9d7 | 452 | bdrv_do_drained_begin_quiesce(bs, parent, ignore_bds_parents); |
d30b8e64 | 453 | |
b0165585 | 454 | if (recursive) { |
6cd5c9d7 | 455 | assert(!ignore_bds_parents); |
d736f119 | 456 | bs->recursive_quiesce_counter++; |
b0165585 | 457 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
6cd5c9d7 KW |
458 | bdrv_do_drained_begin(child->bs, true, child, ignore_bds_parents, |
459 | false); | |
b0165585 KW |
460 | } |
461 | } | |
fe4f0614 KW |
462 | |
463 | /* | |
464 | * Wait for drained requests to finish. | |
465 | * | |
466 | * Calling BDRV_POLL_WHILE() only once for the top-level node is okay: The | |
467 | * call is needed so things in this AioContext can make progress even | |
468 | * though we don't return to the main AioContext loop - this automatically | |
469 | * includes other nodes in the same AioContext and therefore all child | |
470 | * nodes. | |
471 | */ | |
472 | if (poll) { | |
6cd5c9d7 | 473 | assert(!ignore_bds_parents); |
fe4f0614 KW |
474 | BDRV_POLL_WHILE(bs, bdrv_drain_poll_top_level(bs, recursive, parent)); |
475 | } | |
6820643f KW |
476 | } |
477 | ||
0152bf40 KW |
478 | void bdrv_drained_begin(BlockDriverState *bs) |
479 | { | |
6cd5c9d7 | 480 | bdrv_do_drained_begin(bs, false, NULL, false, true); |
b0165585 KW |
481 | } |
482 | ||
483 | void bdrv_subtree_drained_begin(BlockDriverState *bs) | |
484 | { | |
6cd5c9d7 | 485 | bdrv_do_drained_begin(bs, true, NULL, false, true); |
0152bf40 KW |
486 | } |
487 | ||
e037c09c HR |
488 | /** |
489 | * This function does not poll, nor must any of its recursively called | |
490 | * functions. The *drained_end_counter pointee will be incremented | |
491 | * once for every background operation scheduled, and decremented once | |
492 | * the operation settles. Therefore, the pointer must remain valid | |
493 | * until the pointee reaches 0. That implies that whoever sets up the | |
494 | * pointee has to poll until it is 0. | |
495 | * | |
496 | * We use atomic operations to access *drained_end_counter, because | |
497 | * (1) when called from bdrv_set_aio_context_ignore(), the subgraph of | |
498 | * @bs may contain nodes in different AioContexts, | |
499 | * (2) bdrv_drain_all_end() uses the same counter for all nodes, | |
500 | * regardless of which AioContext they are in. | |
501 | */ | |
6cd5c9d7 | 502 | static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, |
8e1da77e HR |
503 | BdrvChild *parent, bool ignore_bds_parents, |
504 | int *drained_end_counter) | |
6820643f | 505 | { |
61ad631c | 506 | BdrvChild *child; |
0f115168 KW |
507 | int old_quiesce_counter; |
508 | ||
e037c09c HR |
509 | assert(drained_end_counter != NULL); |
510 | ||
481cad48 | 511 | if (qemu_in_coroutine()) { |
6cd5c9d7 | 512 | bdrv_co_yield_to_drain(bs, false, recursive, parent, ignore_bds_parents, |
8e1da77e | 513 | false, drained_end_counter); |
481cad48 MP |
514 | return; |
515 | } | |
6820643f | 516 | assert(bs->quiesce_counter > 0); |
6820643f | 517 | |
60369b86 | 518 | /* Re-enable things in child-to-parent order */ |
8e1da77e | 519 | bdrv_drain_invoke(bs, false, drained_end_counter); |
e037c09c HR |
520 | bdrv_parent_drained_end(bs, parent, ignore_bds_parents, |
521 | drained_end_counter); | |
5cb2737e | 522 | |
d73415a3 | 523 | old_quiesce_counter = qatomic_fetch_dec(&bs->quiesce_counter); |
0f115168 | 524 | if (old_quiesce_counter == 1) { |
0f115168 KW |
525 | aio_enable_external(bdrv_get_aio_context(bs)); |
526 | } | |
b0165585 KW |
527 | |
528 | if (recursive) { | |
6cd5c9d7 | 529 | assert(!ignore_bds_parents); |
d736f119 | 530 | bs->recursive_quiesce_counter--; |
61ad631c | 531 | QLIST_FOREACH(child, &bs->children, next) { |
8e1da77e HR |
532 | bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents, |
533 | drained_end_counter); | |
b0165585 KW |
534 | } |
535 | } | |
6820643f KW |
536 | } |
537 | ||
0152bf40 KW |
538 | void bdrv_drained_end(BlockDriverState *bs) |
539 | { | |
e037c09c HR |
540 | int drained_end_counter = 0; |
541 | bdrv_do_drained_end(bs, false, NULL, false, &drained_end_counter); | |
d73415a3 | 542 | BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0); |
e037c09c HR |
543 | } |
544 | ||
545 | void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter) | |
546 | { | |
547 | bdrv_do_drained_end(bs, false, NULL, false, drained_end_counter); | |
b0165585 KW |
548 | } |
549 | ||
550 | void bdrv_subtree_drained_end(BlockDriverState *bs) | |
551 | { | |
e037c09c HR |
552 | int drained_end_counter = 0; |
553 | bdrv_do_drained_end(bs, true, NULL, false, &drained_end_counter); | |
d73415a3 | 554 | BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0); |
0152bf40 KW |
555 | } |
556 | ||
d736f119 KW |
557 | void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent) |
558 | { | |
559 | int i; | |
560 | ||
561 | for (i = 0; i < new_parent->recursive_quiesce_counter; i++) { | |
6cd5c9d7 | 562 | bdrv_do_drained_begin(child->bs, true, child, false, true); |
d736f119 KW |
563 | } |
564 | } | |
565 | ||
566 | void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent) | |
567 | { | |
e037c09c | 568 | int drained_end_counter = 0; |
d736f119 KW |
569 | int i; |
570 | ||
571 | for (i = 0; i < old_parent->recursive_quiesce_counter; i++) { | |
e037c09c HR |
572 | bdrv_do_drained_end(child->bs, true, child, false, |
573 | &drained_end_counter); | |
d736f119 | 574 | } |
e037c09c | 575 | |
d73415a3 | 576 | BDRV_POLL_WHILE(child->bs, qatomic_read(&drained_end_counter) > 0); |
d736f119 KW |
577 | } |
578 | ||
61007b31 | 579 | /* |
67da1dc5 FZ |
580 | * Wait for pending requests to complete on a single BlockDriverState subtree, |
581 | * and suspend block driver's internal I/O until next request arrives. | |
61007b31 | 582 | * |
61007b31 SH |
583 | * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState |
584 | * AioContext. | |
585 | */ | |
b6e84c97 | 586 | void coroutine_fn bdrv_co_drain(BlockDriverState *bs) |
61007b31 | 587 | { |
6820643f KW |
588 | assert(qemu_in_coroutine()); |
589 | bdrv_drained_begin(bs); | |
590 | bdrv_drained_end(bs); | |
b6e84c97 | 591 | } |
f406c03c | 592 | |
b6e84c97 PB |
593 | void bdrv_drain(BlockDriverState *bs) |
594 | { | |
6820643f KW |
595 | bdrv_drained_begin(bs); |
596 | bdrv_drained_end(bs); | |
61007b31 SH |
597 | } |
598 | ||
c13ad59f KW |
599 | static void bdrv_drain_assert_idle(BlockDriverState *bs) |
600 | { | |
601 | BdrvChild *child, *next; | |
602 | ||
d73415a3 | 603 | assert(qatomic_read(&bs->in_flight) == 0); |
c13ad59f KW |
604 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
605 | bdrv_drain_assert_idle(child->bs); | |
606 | } | |
607 | } | |
608 | ||
0f12264e KW |
609 | unsigned int bdrv_drain_all_count = 0; |
610 | ||
611 | static bool bdrv_drain_all_poll(void) | |
612 | { | |
613 | BlockDriverState *bs = NULL; | |
614 | bool result = false; | |
615 | ||
0f12264e KW |
616 | /* bdrv_drain_poll() can't make changes to the graph and we are holding the |
617 | * main AioContext lock, so iterating bdrv_next_all_states() is safe. */ | |
618 | while ((bs = bdrv_next_all_states(bs))) { | |
619 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
620 | aio_context_acquire(aio_context); | |
621 | result |= bdrv_drain_poll(bs, false, NULL, true); | |
622 | aio_context_release(aio_context); | |
623 | } | |
624 | ||
625 | return result; | |
626 | } | |
627 | ||
61007b31 SH |
628 | /* |
629 | * Wait for pending requests to complete across all BlockDriverStates | |
630 | * | |
631 | * This function does not flush data to disk, use bdrv_flush_all() for that | |
632 | * after calling this function. | |
c0778f66 AG |
633 | * |
634 | * This pauses all block jobs and disables external clients. It must | |
635 | * be paired with bdrv_drain_all_end(). | |
636 | * | |
637 | * NOTE: no new block jobs or BlockDriverStates can be created between | |
638 | * the bdrv_drain_all_begin() and bdrv_drain_all_end() calls. | |
61007b31 | 639 | */ |
c0778f66 | 640 | void bdrv_drain_all_begin(void) |
61007b31 | 641 | { |
0f12264e | 642 | BlockDriverState *bs = NULL; |
61007b31 | 643 | |
c8ca33d0 | 644 | if (qemu_in_coroutine()) { |
8e1da77e | 645 | bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, NULL); |
c8ca33d0 KW |
646 | return; |
647 | } | |
648 | ||
c8aa7895 PD |
649 | /* |
650 | * bdrv queue is managed by record/replay, | |
651 | * waiting for finishing the I/O requests may | |
652 | * be infinite | |
653 | */ | |
654 | if (replay_events_enabled()) { | |
655 | return; | |
656 | } | |
657 | ||
0f12264e KW |
658 | /* AIO_WAIT_WHILE() with a NULL context can only be called from the main |
659 | * loop AioContext, so make sure we're in the main context. */ | |
9a7e86c8 | 660 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
0f12264e KW |
661 | assert(bdrv_drain_all_count < INT_MAX); |
662 | bdrv_drain_all_count++; | |
9a7e86c8 | 663 | |
0f12264e KW |
664 | /* Quiesce all nodes, without polling in-flight requests yet. The graph |
665 | * cannot change during this loop. */ | |
666 | while ((bs = bdrv_next_all_states(bs))) { | |
61007b31 SH |
667 | AioContext *aio_context = bdrv_get_aio_context(bs); |
668 | ||
669 | aio_context_acquire(aio_context); | |
0f12264e | 670 | bdrv_do_drained_begin(bs, false, NULL, true, false); |
61007b31 SH |
671 | aio_context_release(aio_context); |
672 | } | |
673 | ||
0f12264e | 674 | /* Now poll the in-flight requests */ |
cfe29d82 | 675 | AIO_WAIT_WHILE(NULL, bdrv_drain_all_poll()); |
0f12264e KW |
676 | |
677 | while ((bs = bdrv_next_all_states(bs))) { | |
c13ad59f | 678 | bdrv_drain_assert_idle(bs); |
61007b31 | 679 | } |
c0778f66 AG |
680 | } |
681 | ||
1a6d3bd2 GK |
682 | void bdrv_drain_all_end_quiesce(BlockDriverState *bs) |
683 | { | |
684 | int drained_end_counter = 0; | |
685 | ||
686 | g_assert(bs->quiesce_counter > 0); | |
687 | g_assert(!bs->refcnt); | |
688 | ||
689 | while (bs->quiesce_counter) { | |
690 | bdrv_do_drained_end(bs, false, NULL, true, &drained_end_counter); | |
691 | } | |
692 | BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0); | |
693 | } | |
694 | ||
c0778f66 AG |
695 | void bdrv_drain_all_end(void) |
696 | { | |
0f12264e | 697 | BlockDriverState *bs = NULL; |
e037c09c | 698 | int drained_end_counter = 0; |
c0778f66 | 699 | |
c8aa7895 PD |
700 | /* |
701 | * bdrv queue is managed by record/replay, | |
702 | * waiting for finishing the I/O requests may | |
703 | * be endless | |
704 | */ | |
705 | if (replay_events_enabled()) { | |
706 | return; | |
707 | } | |
708 | ||
0f12264e | 709 | while ((bs = bdrv_next_all_states(bs))) { |
61007b31 SH |
710 | AioContext *aio_context = bdrv_get_aio_context(bs); |
711 | ||
712 | aio_context_acquire(aio_context); | |
e037c09c | 713 | bdrv_do_drained_end(bs, false, NULL, true, &drained_end_counter); |
61007b31 SH |
714 | aio_context_release(aio_context); |
715 | } | |
0f12264e | 716 | |
e037c09c | 717 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
d73415a3 | 718 | AIO_WAIT_WHILE(NULL, qatomic_read(&drained_end_counter) > 0); |
e037c09c | 719 | |
0f12264e KW |
720 | assert(bdrv_drain_all_count > 0); |
721 | bdrv_drain_all_count--; | |
61007b31 SH |
722 | } |
723 | ||
c0778f66 AG |
724 | void bdrv_drain_all(void) |
725 | { | |
726 | bdrv_drain_all_begin(); | |
727 | bdrv_drain_all_end(); | |
728 | } | |
729 | ||
61007b31 SH |
730 | /** |
731 | * Remove an active request from the tracked requests list | |
732 | * | |
733 | * This function should be called when a tracked request is completing. | |
734 | */ | |
735 | static void tracked_request_end(BdrvTrackedRequest *req) | |
736 | { | |
737 | if (req->serialising) { | |
d73415a3 | 738 | qatomic_dec(&req->bs->serialising_in_flight); |
61007b31 SH |
739 | } |
740 | ||
3783fa3d | 741 | qemu_co_mutex_lock(&req->bs->reqs_lock); |
61007b31 SH |
742 | QLIST_REMOVE(req, list); |
743 | qemu_co_queue_restart_all(&req->wait_queue); | |
3783fa3d | 744 | qemu_co_mutex_unlock(&req->bs->reqs_lock); |
61007b31 SH |
745 | } |
746 | ||
747 | /** | |
748 | * Add an active request to the tracked requests list | |
749 | */ | |
750 | static void tracked_request_begin(BdrvTrackedRequest *req, | |
751 | BlockDriverState *bs, | |
752 | int64_t offset, | |
80247264 | 753 | int64_t bytes, |
ebde595c | 754 | enum BdrvTrackedRequestType type) |
61007b31 | 755 | { |
80247264 | 756 | bdrv_check_request(offset, bytes, &error_abort); |
22931a15 | 757 | |
61007b31 SH |
758 | *req = (BdrvTrackedRequest){ |
759 | .bs = bs, | |
760 | .offset = offset, | |
761 | .bytes = bytes, | |
ebde595c | 762 | .type = type, |
61007b31 SH |
763 | .co = qemu_coroutine_self(), |
764 | .serialising = false, | |
765 | .overlap_offset = offset, | |
766 | .overlap_bytes = bytes, | |
767 | }; | |
768 | ||
769 | qemu_co_queue_init(&req->wait_queue); | |
770 | ||
3783fa3d | 771 | qemu_co_mutex_lock(&bs->reqs_lock); |
61007b31 | 772 | QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); |
3783fa3d | 773 | qemu_co_mutex_unlock(&bs->reqs_lock); |
61007b31 SH |
774 | } |
775 | ||
3ba0e1a0 | 776 | static bool tracked_request_overlaps(BdrvTrackedRequest *req, |
80247264 | 777 | int64_t offset, int64_t bytes) |
3ba0e1a0 | 778 | { |
80247264 EB |
779 | bdrv_check_request(offset, bytes, &error_abort); |
780 | ||
3ba0e1a0 PB |
781 | /* aaaa bbbb */ |
782 | if (offset >= req->overlap_offset + req->overlap_bytes) { | |
783 | return false; | |
784 | } | |
785 | /* bbbb aaaa */ | |
786 | if (req->overlap_offset >= offset + bytes) { | |
787 | return false; | |
788 | } | |
789 | return true; | |
790 | } | |
791 | ||
3183937f VSO |
792 | /* Called with self->bs->reqs_lock held */ |
793 | static BdrvTrackedRequest * | |
794 | bdrv_find_conflicting_request(BdrvTrackedRequest *self) | |
795 | { | |
796 | BdrvTrackedRequest *req; | |
797 | ||
798 | QLIST_FOREACH(req, &self->bs->tracked_requests, list) { | |
799 | if (req == self || (!req->serialising && !self->serialising)) { | |
800 | continue; | |
801 | } | |
802 | if (tracked_request_overlaps(req, self->overlap_offset, | |
803 | self->overlap_bytes)) | |
804 | { | |
805 | /* | |
806 | * Hitting this means there was a reentrant request, for | |
807 | * example, a block driver issuing nested requests. This must | |
808 | * never happen since it means deadlock. | |
809 | */ | |
810 | assert(qemu_coroutine_self() != req->co); | |
811 | ||
812 | /* | |
813 | * If the request is already (indirectly) waiting for us, or | |
814 | * will wait for us as soon as it wakes up, then just go on | |
815 | * (instead of producing a deadlock in the former case). | |
816 | */ | |
817 | if (!req->waiting_for) { | |
818 | return req; | |
819 | } | |
820 | } | |
821 | } | |
822 | ||
823 | return NULL; | |
824 | } | |
825 | ||
ec1c8868 | 826 | /* Called with self->bs->reqs_lock held */ |
3ba0e1a0 | 827 | static bool coroutine_fn |
ec1c8868 | 828 | bdrv_wait_serialising_requests_locked(BdrvTrackedRequest *self) |
3ba0e1a0 PB |
829 | { |
830 | BdrvTrackedRequest *req; | |
3ba0e1a0 PB |
831 | bool waited = false; |
832 | ||
3183937f VSO |
833 | while ((req = bdrv_find_conflicting_request(self))) { |
834 | self->waiting_for = req; | |
ec1c8868 | 835 | qemu_co_queue_wait(&req->wait_queue, &self->bs->reqs_lock); |
3183937f VSO |
836 | self->waiting_for = NULL; |
837 | waited = true; | |
838 | } | |
839 | ||
3ba0e1a0 PB |
840 | return waited; |
841 | } | |
842 | ||
8ac5aab2 VSO |
843 | /* Called with req->bs->reqs_lock held */ |
844 | static void tracked_request_set_serialising(BdrvTrackedRequest *req, | |
845 | uint64_t align) | |
61007b31 SH |
846 | { |
847 | int64_t overlap_offset = req->offset & ~(align - 1); | |
80247264 EB |
848 | int64_t overlap_bytes = |
849 | ROUND_UP(req->offset + req->bytes, align) - overlap_offset; | |
850 | ||
851 | bdrv_check_request(req->offset, req->bytes, &error_abort); | |
61007b31 SH |
852 | |
853 | if (!req->serialising) { | |
d73415a3 | 854 | qatomic_inc(&req->bs->serialising_in_flight); |
61007b31 SH |
855 | req->serialising = true; |
856 | } | |
857 | ||
858 | req->overlap_offset = MIN(req->overlap_offset, overlap_offset); | |
859 | req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); | |
09d2f948 VSO |
860 | } |
861 | ||
c28107e9 HR |
862 | /** |
863 | * Return the tracked request on @bs for the current coroutine, or | |
864 | * NULL if there is none. | |
865 | */ | |
866 | BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs) | |
867 | { | |
868 | BdrvTrackedRequest *req; | |
869 | Coroutine *self = qemu_coroutine_self(); | |
870 | ||
871 | QLIST_FOREACH(req, &bs->tracked_requests, list) { | |
872 | if (req->co == self) { | |
873 | return req; | |
874 | } | |
875 | } | |
876 | ||
877 | return NULL; | |
878 | } | |
879 | ||
244483e6 KW |
880 | /** |
881 | * Round a region to cluster boundaries | |
882 | */ | |
883 | void bdrv_round_to_clusters(BlockDriverState *bs, | |
7cfd5275 | 884 | int64_t offset, int64_t bytes, |
244483e6 | 885 | int64_t *cluster_offset, |
7cfd5275 | 886 | int64_t *cluster_bytes) |
244483e6 KW |
887 | { |
888 | BlockDriverInfo bdi; | |
889 | ||
890 | if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { | |
891 | *cluster_offset = offset; | |
892 | *cluster_bytes = bytes; | |
893 | } else { | |
894 | int64_t c = bdi.cluster_size; | |
895 | *cluster_offset = QEMU_ALIGN_DOWN(offset, c); | |
896 | *cluster_bytes = QEMU_ALIGN_UP(offset - *cluster_offset + bytes, c); | |
897 | } | |
898 | } | |
899 | ||
61007b31 SH |
900 | static int bdrv_get_cluster_size(BlockDriverState *bs) |
901 | { | |
902 | BlockDriverInfo bdi; | |
903 | int ret; | |
904 | ||
905 | ret = bdrv_get_info(bs, &bdi); | |
906 | if (ret < 0 || bdi.cluster_size == 0) { | |
a5b8dd2c | 907 | return bs->bl.request_alignment; |
61007b31 SH |
908 | } else { |
909 | return bdi.cluster_size; | |
910 | } | |
911 | } | |
912 | ||
99723548 PB |
913 | void bdrv_inc_in_flight(BlockDriverState *bs) |
914 | { | |
d73415a3 | 915 | qatomic_inc(&bs->in_flight); |
99723548 PB |
916 | } |
917 | ||
c9d1a561 PB |
918 | void bdrv_wakeup(BlockDriverState *bs) |
919 | { | |
cfe29d82 | 920 | aio_wait_kick(); |
c9d1a561 PB |
921 | } |
922 | ||
99723548 PB |
923 | void bdrv_dec_in_flight(BlockDriverState *bs) |
924 | { | |
d73415a3 | 925 | qatomic_dec(&bs->in_flight); |
c9d1a561 | 926 | bdrv_wakeup(bs); |
99723548 PB |
927 | } |
928 | ||
18fbd0de | 929 | static bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self) |
61007b31 SH |
930 | { |
931 | BlockDriverState *bs = self->bs; | |
61007b31 SH |
932 | bool waited = false; |
933 | ||
d73415a3 | 934 | if (!qatomic_read(&bs->serialising_in_flight)) { |
61007b31 SH |
935 | return false; |
936 | } | |
937 | ||
3ba0e1a0 | 938 | qemu_co_mutex_lock(&bs->reqs_lock); |
ec1c8868 | 939 | waited = bdrv_wait_serialising_requests_locked(self); |
3ba0e1a0 | 940 | qemu_co_mutex_unlock(&bs->reqs_lock); |
61007b31 SH |
941 | |
942 | return waited; | |
943 | } | |
944 | ||
8ac5aab2 VSO |
945 | bool coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req, |
946 | uint64_t align) | |
947 | { | |
948 | bool waited; | |
949 | ||
950 | qemu_co_mutex_lock(&req->bs->reqs_lock); | |
951 | ||
952 | tracked_request_set_serialising(req, align); | |
953 | waited = bdrv_wait_serialising_requests_locked(req); | |
954 | ||
955 | qemu_co_mutex_unlock(&req->bs->reqs_lock); | |
956 | ||
957 | return waited; | |
958 | } | |
959 | ||
558902cc VSO |
960 | int bdrv_check_qiov_request(int64_t offset, int64_t bytes, |
961 | QEMUIOVector *qiov, size_t qiov_offset, | |
962 | Error **errp) | |
61007b31 | 963 | { |
63f4ad11 VSO |
964 | /* |
965 | * Check generic offset/bytes correctness | |
966 | */ | |
967 | ||
69b55e03 VSO |
968 | if (offset < 0) { |
969 | error_setg(errp, "offset is negative: %" PRIi64, offset); | |
970 | return -EIO; | |
971 | } | |
972 | ||
973 | if (bytes < 0) { | |
974 | error_setg(errp, "bytes is negative: %" PRIi64, bytes); | |
61007b31 SH |
975 | return -EIO; |
976 | } | |
977 | ||
8b117001 | 978 | if (bytes > BDRV_MAX_LENGTH) { |
69b55e03 VSO |
979 | error_setg(errp, "bytes(%" PRIi64 ") exceeds maximum(%" PRIi64 ")", |
980 | bytes, BDRV_MAX_LENGTH); | |
981 | return -EIO; | |
982 | } | |
983 | ||
984 | if (offset > BDRV_MAX_LENGTH) { | |
985 | error_setg(errp, "offset(%" PRIi64 ") exceeds maximum(%" PRIi64 ")", | |
986 | offset, BDRV_MAX_LENGTH); | |
8b117001 VSO |
987 | return -EIO; |
988 | } | |
989 | ||
990 | if (offset > BDRV_MAX_LENGTH - bytes) { | |
69b55e03 VSO |
991 | error_setg(errp, "sum of offset(%" PRIi64 ") and bytes(%" PRIi64 ") " |
992 | "exceeds maximum(%" PRIi64 ")", offset, bytes, | |
993 | BDRV_MAX_LENGTH); | |
8b117001 VSO |
994 | return -EIO; |
995 | } | |
996 | ||
63f4ad11 VSO |
997 | if (!qiov) { |
998 | return 0; | |
999 | } | |
1000 | ||
1001 | /* | |
1002 | * Check qiov and qiov_offset | |
1003 | */ | |
1004 | ||
1005 | if (qiov_offset > qiov->size) { | |
1006 | error_setg(errp, "qiov_offset(%zu) overflow io vector size(%zu)", | |
1007 | qiov_offset, qiov->size); | |
1008 | return -EIO; | |
1009 | } | |
1010 | ||
1011 | if (bytes > qiov->size - qiov_offset) { | |
1012 | error_setg(errp, "bytes(%" PRIi64 ") + qiov_offset(%zu) overflow io " | |
1013 | "vector size(%zu)", bytes, qiov_offset, qiov->size); | |
1014 | return -EIO; | |
1015 | } | |
1016 | ||
8b117001 VSO |
1017 | return 0; |
1018 | } | |
1019 | ||
63f4ad11 VSO |
1020 | int bdrv_check_request(int64_t offset, int64_t bytes, Error **errp) |
1021 | { | |
1022 | return bdrv_check_qiov_request(offset, bytes, NULL, 0, errp); | |
1023 | } | |
1024 | ||
1025 | static int bdrv_check_request32(int64_t offset, int64_t bytes, | |
1026 | QEMUIOVector *qiov, size_t qiov_offset) | |
8b117001 | 1027 | { |
63f4ad11 | 1028 | int ret = bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, NULL); |
8b117001 VSO |
1029 | if (ret < 0) { |
1030 | return ret; | |
1031 | } | |
1032 | ||
1033 | if (bytes > BDRV_REQUEST_MAX_BYTES) { | |
61007b31 SH |
1034 | return -EIO; |
1035 | } | |
1036 | ||
1037 | return 0; | |
1038 | } | |
1039 | ||
720ff280 | 1040 | int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, |
e9e52efd | 1041 | int64_t bytes, BdrvRequestFlags flags) |
61007b31 | 1042 | { |
fae2681a VSO |
1043 | return bdrv_pwritev(child, offset, bytes, NULL, |
1044 | BDRV_REQ_ZERO_WRITE | flags); | |
61007b31 SH |
1045 | } |
1046 | ||
1047 | /* | |
74021bc4 | 1048 | * Completely zero out a block device with the help of bdrv_pwrite_zeroes. |
61007b31 SH |
1049 | * The operation is sped up by checking the block status and only writing |
1050 | * zeroes to the device if they currently do not return zeroes. Optional | |
74021bc4 | 1051 | * flags are passed through to bdrv_pwrite_zeroes (e.g. BDRV_REQ_MAY_UNMAP, |
465fe887 | 1052 | * BDRV_REQ_FUA). |
61007b31 | 1053 | * |
f4649069 | 1054 | * Returns < 0 on error, 0 on success. For error codes see bdrv_pwrite(). |
61007b31 | 1055 | */ |
720ff280 | 1056 | int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags) |
61007b31 | 1057 | { |
237d78f8 EB |
1058 | int ret; |
1059 | int64_t target_size, bytes, offset = 0; | |
720ff280 | 1060 | BlockDriverState *bs = child->bs; |
61007b31 | 1061 | |
7286d610 EB |
1062 | target_size = bdrv_getlength(bs); |
1063 | if (target_size < 0) { | |
1064 | return target_size; | |
61007b31 SH |
1065 | } |
1066 | ||
1067 | for (;;) { | |
7286d610 EB |
1068 | bytes = MIN(target_size - offset, BDRV_REQUEST_MAX_BYTES); |
1069 | if (bytes <= 0) { | |
61007b31 SH |
1070 | return 0; |
1071 | } | |
237d78f8 | 1072 | ret = bdrv_block_status(bs, offset, bytes, &bytes, NULL, NULL); |
61007b31 | 1073 | if (ret < 0) { |
61007b31 SH |
1074 | return ret; |
1075 | } | |
1076 | if (ret & BDRV_BLOCK_ZERO) { | |
237d78f8 | 1077 | offset += bytes; |
61007b31 SH |
1078 | continue; |
1079 | } | |
237d78f8 | 1080 | ret = bdrv_pwrite_zeroes(child, offset, bytes, flags); |
61007b31 | 1081 | if (ret < 0) { |
61007b31 SH |
1082 | return ret; |
1083 | } | |
237d78f8 | 1084 | offset += bytes; |
61007b31 SH |
1085 | } |
1086 | } | |
1087 | ||
2e11d756 | 1088 | /* See bdrv_pwrite() for the return codes */ |
e9e52efd | 1089 | int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes) |
61007b31 | 1090 | { |
fae2681a | 1091 | int ret; |
0d93ed08 | 1092 | QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); |
61007b31 SH |
1093 | |
1094 | if (bytes < 0) { | |
1095 | return -EINVAL; | |
1096 | } | |
1097 | ||
fae2681a | 1098 | ret = bdrv_preadv(child, offset, bytes, &qiov, 0); |
61007b31 | 1099 | |
fae2681a | 1100 | return ret < 0 ? ret : bytes; |
61007b31 SH |
1101 | } |
1102 | ||
2e11d756 AG |
1103 | /* Return no. of bytes on success or < 0 on error. Important errors are: |
1104 | -EIO generic I/O error (may happen for all errors) | |
1105 | -ENOMEDIUM No media inserted. | |
1106 | -EINVAL Invalid offset or number of bytes | |
1107 | -EACCES Trying to write a read-only device | |
1108 | */ | |
e9e52efd VSO |
1109 | int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, |
1110 | int64_t bytes) | |
61007b31 | 1111 | { |
fae2681a | 1112 | int ret; |
0d93ed08 | 1113 | QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); |
61007b31 SH |
1114 | |
1115 | if (bytes < 0) { | |
1116 | return -EINVAL; | |
1117 | } | |
1118 | ||
fae2681a VSO |
1119 | ret = bdrv_pwritev(child, offset, bytes, &qiov, 0); |
1120 | ||
1121 | return ret < 0 ? ret : bytes; | |
61007b31 SH |
1122 | } |
1123 | ||
1124 | /* | |
1125 | * Writes to the file and ensures that no writes are reordered across this | |
1126 | * request (acts as a barrier) | |
1127 | * | |
1128 | * Returns 0 on success, -errno in error cases. | |
1129 | */ | |
d9ca2ea2 | 1130 | int bdrv_pwrite_sync(BdrvChild *child, int64_t offset, |
e9e52efd | 1131 | const void *buf, int64_t count) |
61007b31 SH |
1132 | { |
1133 | int ret; | |
1134 | ||
d9ca2ea2 | 1135 | ret = bdrv_pwrite(child, offset, buf, count); |
61007b31 SH |
1136 | if (ret < 0) { |
1137 | return ret; | |
1138 | } | |
1139 | ||
d9ca2ea2 | 1140 | ret = bdrv_flush(child->bs); |
855a6a93 KW |
1141 | if (ret < 0) { |
1142 | return ret; | |
61007b31 SH |
1143 | } |
1144 | ||
1145 | return 0; | |
1146 | } | |
1147 | ||
08844473 KW |
1148 | typedef struct CoroutineIOCompletion { |
1149 | Coroutine *coroutine; | |
1150 | int ret; | |
1151 | } CoroutineIOCompletion; | |
1152 | ||
1153 | static void bdrv_co_io_em_complete(void *opaque, int ret) | |
1154 | { | |
1155 | CoroutineIOCompletion *co = opaque; | |
1156 | ||
1157 | co->ret = ret; | |
b9e413dd | 1158 | aio_co_wake(co->coroutine); |
08844473 KW |
1159 | } |
1160 | ||
166fe960 | 1161 | static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs, |
17abcbee | 1162 | int64_t offset, int64_t bytes, |
ac850bf0 VSO |
1163 | QEMUIOVector *qiov, |
1164 | size_t qiov_offset, int flags) | |
166fe960 KW |
1165 | { |
1166 | BlockDriver *drv = bs->drv; | |
3fb06697 KW |
1167 | int64_t sector_num; |
1168 | unsigned int nb_sectors; | |
ac850bf0 VSO |
1169 | QEMUIOVector local_qiov; |
1170 | int ret; | |
3fb06697 | 1171 | |
17abcbee | 1172 | bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort); |
fa166538 | 1173 | assert(!(flags & ~BDRV_REQ_MASK)); |
fe0480d6 | 1174 | assert(!(flags & BDRV_REQ_NO_FALLBACK)); |
fa166538 | 1175 | |
d470ad42 HR |
1176 | if (!drv) { |
1177 | return -ENOMEDIUM; | |
1178 | } | |
1179 | ||
ac850bf0 VSO |
1180 | if (drv->bdrv_co_preadv_part) { |
1181 | return drv->bdrv_co_preadv_part(bs, offset, bytes, qiov, qiov_offset, | |
1182 | flags); | |
1183 | } | |
1184 | ||
1185 | if (qiov_offset > 0 || bytes != qiov->size) { | |
1186 | qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes); | |
1187 | qiov = &local_qiov; | |
1188 | } | |
1189 | ||
3fb06697 | 1190 | if (drv->bdrv_co_preadv) { |
ac850bf0 VSO |
1191 | ret = drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags); |
1192 | goto out; | |
3fb06697 KW |
1193 | } |
1194 | ||
edfab6a0 | 1195 | if (drv->bdrv_aio_preadv) { |
08844473 KW |
1196 | BlockAIOCB *acb; |
1197 | CoroutineIOCompletion co = { | |
1198 | .coroutine = qemu_coroutine_self(), | |
1199 | }; | |
1200 | ||
edfab6a0 EB |
1201 | acb = drv->bdrv_aio_preadv(bs, offset, bytes, qiov, flags, |
1202 | bdrv_co_io_em_complete, &co); | |
08844473 | 1203 | if (acb == NULL) { |
ac850bf0 VSO |
1204 | ret = -EIO; |
1205 | goto out; | |
08844473 KW |
1206 | } else { |
1207 | qemu_coroutine_yield(); | |
ac850bf0 VSO |
1208 | ret = co.ret; |
1209 | goto out; | |
08844473 KW |
1210 | } |
1211 | } | |
edfab6a0 EB |
1212 | |
1213 | sector_num = offset >> BDRV_SECTOR_BITS; | |
1214 | nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
1215 | ||
1bbbf32d NS |
1216 | assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)); |
1217 | assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE)); | |
41ae31e3 | 1218 | assert(bytes <= BDRV_REQUEST_MAX_BYTES); |
edfab6a0 EB |
1219 | assert(drv->bdrv_co_readv); |
1220 | ||
ac850bf0 VSO |
1221 | ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); |
1222 | ||
1223 | out: | |
1224 | if (qiov == &local_qiov) { | |
1225 | qemu_iovec_destroy(&local_qiov); | |
1226 | } | |
1227 | ||
1228 | return ret; | |
166fe960 KW |
1229 | } |
1230 | ||
78a07294 | 1231 | static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs, |
17abcbee | 1232 | int64_t offset, int64_t bytes, |
ac850bf0 | 1233 | QEMUIOVector *qiov, |
e75abeda VSO |
1234 | size_t qiov_offset, |
1235 | BdrvRequestFlags flags) | |
78a07294 KW |
1236 | { |
1237 | BlockDriver *drv = bs->drv; | |
3fb06697 KW |
1238 | int64_t sector_num; |
1239 | unsigned int nb_sectors; | |
ac850bf0 | 1240 | QEMUIOVector local_qiov; |
78a07294 KW |
1241 | int ret; |
1242 | ||
17abcbee | 1243 | bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort); |
fa166538 | 1244 | assert(!(flags & ~BDRV_REQ_MASK)); |
fe0480d6 | 1245 | assert(!(flags & BDRV_REQ_NO_FALLBACK)); |
fa166538 | 1246 | |
d470ad42 HR |
1247 | if (!drv) { |
1248 | return -ENOMEDIUM; | |
1249 | } | |
1250 | ||
ac850bf0 VSO |
1251 | if (drv->bdrv_co_pwritev_part) { |
1252 | ret = drv->bdrv_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, | |
1253 | flags & bs->supported_write_flags); | |
1254 | flags &= ~bs->supported_write_flags; | |
1255 | goto emulate_flags; | |
1256 | } | |
1257 | ||
1258 | if (qiov_offset > 0 || bytes != qiov->size) { | |
1259 | qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes); | |
1260 | qiov = &local_qiov; | |
1261 | } | |
1262 | ||
3fb06697 | 1263 | if (drv->bdrv_co_pwritev) { |
515c2f43 KW |
1264 | ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov, |
1265 | flags & bs->supported_write_flags); | |
1266 | flags &= ~bs->supported_write_flags; | |
3fb06697 KW |
1267 | goto emulate_flags; |
1268 | } | |
1269 | ||
edfab6a0 | 1270 | if (drv->bdrv_aio_pwritev) { |
08844473 KW |
1271 | BlockAIOCB *acb; |
1272 | CoroutineIOCompletion co = { | |
1273 | .coroutine = qemu_coroutine_self(), | |
1274 | }; | |
1275 | ||
edfab6a0 EB |
1276 | acb = drv->bdrv_aio_pwritev(bs, offset, bytes, qiov, |
1277 | flags & bs->supported_write_flags, | |
1278 | bdrv_co_io_em_complete, &co); | |
1279 | flags &= ~bs->supported_write_flags; | |
08844473 | 1280 | if (acb == NULL) { |
3fb06697 | 1281 | ret = -EIO; |
08844473 KW |
1282 | } else { |
1283 | qemu_coroutine_yield(); | |
3fb06697 | 1284 | ret = co.ret; |
08844473 | 1285 | } |
edfab6a0 EB |
1286 | goto emulate_flags; |
1287 | } | |
1288 | ||
1289 | sector_num = offset >> BDRV_SECTOR_BITS; | |
1290 | nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
1291 | ||
1bbbf32d NS |
1292 | assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)); |
1293 | assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE)); | |
41ae31e3 | 1294 | assert(bytes <= BDRV_REQUEST_MAX_BYTES); |
edfab6a0 | 1295 | |
e18a58b4 EB |
1296 | assert(drv->bdrv_co_writev); |
1297 | ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov, | |
1298 | flags & bs->supported_write_flags); | |
1299 | flags &= ~bs->supported_write_flags; | |
78a07294 | 1300 | |
3fb06697 | 1301 | emulate_flags: |
4df863f3 | 1302 | if (ret == 0 && (flags & BDRV_REQ_FUA)) { |
78a07294 KW |
1303 | ret = bdrv_co_flush(bs); |
1304 | } | |
1305 | ||
ac850bf0 VSO |
1306 | if (qiov == &local_qiov) { |
1307 | qemu_iovec_destroy(&local_qiov); | |
1308 | } | |
1309 | ||
78a07294 KW |
1310 | return ret; |
1311 | } | |
1312 | ||
29a298af | 1313 | static int coroutine_fn |
17abcbee VSO |
1314 | bdrv_driver_pwritev_compressed(BlockDriverState *bs, int64_t offset, |
1315 | int64_t bytes, QEMUIOVector *qiov, | |
ac850bf0 | 1316 | size_t qiov_offset) |
29a298af PB |
1317 | { |
1318 | BlockDriver *drv = bs->drv; | |
ac850bf0 VSO |
1319 | QEMUIOVector local_qiov; |
1320 | int ret; | |
29a298af | 1321 | |
17abcbee VSO |
1322 | bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort); |
1323 | ||
d470ad42 HR |
1324 | if (!drv) { |
1325 | return -ENOMEDIUM; | |
1326 | } | |
1327 | ||
ac850bf0 | 1328 | if (!block_driver_can_compress(drv)) { |
29a298af PB |
1329 | return -ENOTSUP; |
1330 | } | |
1331 | ||
ac850bf0 VSO |
1332 | if (drv->bdrv_co_pwritev_compressed_part) { |
1333 | return drv->bdrv_co_pwritev_compressed_part(bs, offset, bytes, | |
1334 | qiov, qiov_offset); | |
1335 | } | |
1336 | ||
1337 | if (qiov_offset == 0) { | |
1338 | return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov); | |
1339 | } | |
1340 | ||
1341 | qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes); | |
1342 | ret = drv->bdrv_co_pwritev_compressed(bs, offset, bytes, &local_qiov); | |
1343 | qemu_iovec_destroy(&local_qiov); | |
1344 | ||
1345 | return ret; | |
29a298af PB |
1346 | } |
1347 | ||
85c97ca7 | 1348 | static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, |
9df5afbd | 1349 | int64_t offset, int64_t bytes, QEMUIOVector *qiov, |
1143ec5e | 1350 | size_t qiov_offset, int flags) |
61007b31 | 1351 | { |
85c97ca7 KW |
1352 | BlockDriverState *bs = child->bs; |
1353 | ||
61007b31 SH |
1354 | /* Perform I/O through a temporary buffer so that users who scribble over |
1355 | * their read buffer while the operation is in progress do not end up | |
1356 | * modifying the image file. This is critical for zero-copy guest I/O | |
1357 | * where anything might happen inside guest memory. | |
1358 | */ | |
2275cc90 | 1359 | void *bounce_buffer = NULL; |
61007b31 SH |
1360 | |
1361 | BlockDriver *drv = bs->drv; | |
244483e6 | 1362 | int64_t cluster_offset; |
7cfd5275 | 1363 | int64_t cluster_bytes; |
9df5afbd | 1364 | int64_t skip_bytes; |
61007b31 | 1365 | int ret; |
cb2e2878 EB |
1366 | int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, |
1367 | BDRV_REQUEST_MAX_BYTES); | |
9df5afbd | 1368 | int64_t progress = 0; |
8644476e | 1369 | bool skip_write; |
61007b31 | 1370 | |
9df5afbd VSO |
1371 | bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort); |
1372 | ||
d470ad42 HR |
1373 | if (!drv) { |
1374 | return -ENOMEDIUM; | |
1375 | } | |
1376 | ||
8644476e HR |
1377 | /* |
1378 | * Do not write anything when the BDS is inactive. That is not | |
1379 | * allowed, and it would not help. | |
1380 | */ | |
1381 | skip_write = (bs->open_flags & BDRV_O_INACTIVE); | |
1382 | ||
1bf03e66 KW |
1383 | /* FIXME We cannot require callers to have write permissions when all they |
1384 | * are doing is a read request. If we did things right, write permissions | |
1385 | * would be obtained anyway, but internally by the copy-on-read code. As | |
765d9df9 | 1386 | * long as it is implemented here rather than in a separate filter driver, |
1bf03e66 KW |
1387 | * the copy-on-read code doesn't have its own BdrvChild, however, for which |
1388 | * it could request permissions. Therefore we have to bypass the permission | |
1389 | * system for the moment. */ | |
1390 | // assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE)); | |
afa4b293 | 1391 | |
61007b31 | 1392 | /* Cover entire cluster so no additional backing file I/O is required when |
cb2e2878 EB |
1393 | * allocating cluster in the image file. Note that this value may exceed |
1394 | * BDRV_REQUEST_MAX_BYTES (even when the original read did not), which | |
1395 | * is one reason we loop rather than doing it all at once. | |
61007b31 | 1396 | */ |
244483e6 | 1397 | bdrv_round_to_clusters(bs, offset, bytes, &cluster_offset, &cluster_bytes); |
cb2e2878 | 1398 | skip_bytes = offset - cluster_offset; |
61007b31 | 1399 | |
244483e6 KW |
1400 | trace_bdrv_co_do_copy_on_readv(bs, offset, bytes, |
1401 | cluster_offset, cluster_bytes); | |
61007b31 | 1402 | |
cb2e2878 EB |
1403 | while (cluster_bytes) { |
1404 | int64_t pnum; | |
61007b31 | 1405 | |
8644476e HR |
1406 | if (skip_write) { |
1407 | ret = 1; /* "already allocated", so nothing will be copied */ | |
cb2e2878 | 1408 | pnum = MIN(cluster_bytes, max_transfer); |
8644476e HR |
1409 | } else { |
1410 | ret = bdrv_is_allocated(bs, cluster_offset, | |
1411 | MIN(cluster_bytes, max_transfer), &pnum); | |
1412 | if (ret < 0) { | |
1413 | /* | |
1414 | * Safe to treat errors in querying allocation as if | |
1415 | * unallocated; we'll probably fail again soon on the | |
1416 | * read, but at least that will set a decent errno. | |
1417 | */ | |
1418 | pnum = MIN(cluster_bytes, max_transfer); | |
1419 | } | |
61007b31 | 1420 | |
8644476e HR |
1421 | /* Stop at EOF if the image ends in the middle of the cluster */ |
1422 | if (ret == 0 && pnum == 0) { | |
1423 | assert(progress >= bytes); | |
1424 | break; | |
1425 | } | |
b0ddcbbb | 1426 | |
8644476e HR |
1427 | assert(skip_bytes < pnum); |
1428 | } | |
61007b31 | 1429 | |
cb2e2878 | 1430 | if (ret <= 0) { |
1143ec5e VSO |
1431 | QEMUIOVector local_qiov; |
1432 | ||
cb2e2878 | 1433 | /* Must copy-on-read; use the bounce buffer */ |
0d93ed08 | 1434 | pnum = MIN(pnum, MAX_BOUNCE_BUFFER); |
2275cc90 VSO |
1435 | if (!bounce_buffer) { |
1436 | int64_t max_we_need = MAX(pnum, cluster_bytes - pnum); | |
1437 | int64_t max_allowed = MIN(max_transfer, MAX_BOUNCE_BUFFER); | |
1438 | int64_t bounce_buffer_len = MIN(max_we_need, max_allowed); | |
1439 | ||
1440 | bounce_buffer = qemu_try_blockalign(bs, bounce_buffer_len); | |
1441 | if (!bounce_buffer) { | |
1442 | ret = -ENOMEM; | |
1443 | goto err; | |
1444 | } | |
1445 | } | |
0d93ed08 | 1446 | qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum); |
61007b31 | 1447 | |
cb2e2878 | 1448 | ret = bdrv_driver_preadv(bs, cluster_offset, pnum, |
ac850bf0 | 1449 | &local_qiov, 0, 0); |
cb2e2878 EB |
1450 | if (ret < 0) { |
1451 | goto err; | |
1452 | } | |
1453 | ||
1454 | bdrv_debug_event(bs, BLKDBG_COR_WRITE); | |
1455 | if (drv->bdrv_co_pwrite_zeroes && | |
1456 | buffer_is_zero(bounce_buffer, pnum)) { | |
1457 | /* FIXME: Should we (perhaps conditionally) be setting | |
1458 | * BDRV_REQ_MAY_UNMAP, if it will allow for a sparser copy | |
1459 | * that still correctly reads as zero? */ | |
7adcf59f HR |
1460 | ret = bdrv_co_do_pwrite_zeroes(bs, cluster_offset, pnum, |
1461 | BDRV_REQ_WRITE_UNCHANGED); | |
cb2e2878 EB |
1462 | } else { |
1463 | /* This does not change the data on the disk, it is not | |
1464 | * necessary to flush even in cache=writethrough mode. | |
1465 | */ | |
1466 | ret = bdrv_driver_pwritev(bs, cluster_offset, pnum, | |
ac850bf0 | 1467 | &local_qiov, 0, |
7adcf59f | 1468 | BDRV_REQ_WRITE_UNCHANGED); |
cb2e2878 EB |
1469 | } |
1470 | ||
1471 | if (ret < 0) { | |
1472 | /* It might be okay to ignore write errors for guest | |
1473 | * requests. If this is a deliberate copy-on-read | |
1474 | * then we don't want to ignore the error. Simply | |
1475 | * report it in all cases. | |
1476 | */ | |
1477 | goto err; | |
1478 | } | |
1479 | ||
3299e5ec | 1480 | if (!(flags & BDRV_REQ_PREFETCH)) { |
1143ec5e VSO |
1481 | qemu_iovec_from_buf(qiov, qiov_offset + progress, |
1482 | bounce_buffer + skip_bytes, | |
4ab78b19 | 1483 | MIN(pnum - skip_bytes, bytes - progress)); |
3299e5ec VSO |
1484 | } |
1485 | } else if (!(flags & BDRV_REQ_PREFETCH)) { | |
cb2e2878 | 1486 | /* Read directly into the destination */ |
1143ec5e VSO |
1487 | ret = bdrv_driver_preadv(bs, offset + progress, |
1488 | MIN(pnum - skip_bytes, bytes - progress), | |
1489 | qiov, qiov_offset + progress, 0); | |
cb2e2878 EB |
1490 | if (ret < 0) { |
1491 | goto err; | |
1492 | } | |
1493 | } | |
1494 | ||
1495 | cluster_offset += pnum; | |
1496 | cluster_bytes -= pnum; | |
1497 | progress += pnum - skip_bytes; | |
1498 | skip_bytes = 0; | |
1499 | } | |
1500 | ret = 0; | |
61007b31 SH |
1501 | |
1502 | err: | |
1503 | qemu_vfree(bounce_buffer); | |
1504 | return ret; | |
1505 | } | |
1506 | ||
1507 | /* | |
1508 | * Forwards an already correctly aligned request to the BlockDriver. This | |
1a62d0ac EB |
1509 | * handles copy on read, zeroing after EOF, and fragmentation of large |
1510 | * reads; any other features must be implemented by the caller. | |
61007b31 | 1511 | */ |
85c97ca7 | 1512 | static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, |
8b0c5d76 | 1513 | BdrvTrackedRequest *req, int64_t offset, int64_t bytes, |
65cd4424 | 1514 | int64_t align, QEMUIOVector *qiov, size_t qiov_offset, int flags) |
61007b31 | 1515 | { |
85c97ca7 | 1516 | BlockDriverState *bs = child->bs; |
c9d20029 | 1517 | int64_t total_bytes, max_bytes; |
1a62d0ac | 1518 | int ret = 0; |
8b0c5d76 | 1519 | int64_t bytes_remaining = bytes; |
1a62d0ac | 1520 | int max_transfer; |
61007b31 | 1521 | |
8b0c5d76 | 1522 | bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort); |
49c07526 KW |
1523 | assert(is_power_of_2(align)); |
1524 | assert((offset & (align - 1)) == 0); | |
1525 | assert((bytes & (align - 1)) == 0); | |
abb06c5a | 1526 | assert((bs->open_flags & BDRV_O_NO_IO) == 0); |
1a62d0ac EB |
1527 | max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX), |
1528 | align); | |
a604fa2b EB |
1529 | |
1530 | /* TODO: We would need a per-BDS .supported_read_flags and | |
1531 | * potential fallback support, if we ever implement any read flags | |
1532 | * to pass through to drivers. For now, there aren't any | |
1533 | * passthrough flags. */ | |
c53cb427 | 1534 | assert(!(flags & ~(BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH))); |
61007b31 SH |
1535 | |
1536 | /* Handle Copy on Read and associated serialisation */ | |
1537 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
1538 | /* If we touch the same cluster it counts as an overlap. This | |
1539 | * guarantees that allocating writes will be serialized and not race | |
1540 | * with each other for the same cluster. For example, in copy-on-read | |
1541 | * it ensures that the CoR read and write operations are atomic and | |
1542 | * guest writes cannot interleave between them. */ | |
8ac5aab2 | 1543 | bdrv_make_request_serialising(req, bdrv_get_cluster_size(bs)); |
18fbd0de PB |
1544 | } else { |
1545 | bdrv_wait_serialising_requests(req); | |
61007b31 SH |
1546 | } |
1547 | ||
61007b31 | 1548 | if (flags & BDRV_REQ_COPY_ON_READ) { |
d6a644bb | 1549 | int64_t pnum; |
61007b31 | 1550 | |
897dd0ec AS |
1551 | /* The flag BDRV_REQ_COPY_ON_READ has reached its addressee */ |
1552 | flags &= ~BDRV_REQ_COPY_ON_READ; | |
1553 | ||
88e63df2 | 1554 | ret = bdrv_is_allocated(bs, offset, bytes, &pnum); |
61007b31 SH |
1555 | if (ret < 0) { |
1556 | goto out; | |
1557 | } | |
1558 | ||
88e63df2 | 1559 | if (!ret || pnum != bytes) { |
65cd4424 VSO |
1560 | ret = bdrv_co_do_copy_on_readv(child, offset, bytes, |
1561 | qiov, qiov_offset, flags); | |
3299e5ec VSO |
1562 | goto out; |
1563 | } else if (flags & BDRV_REQ_PREFETCH) { | |
61007b31 SH |
1564 | goto out; |
1565 | } | |
1566 | } | |
1567 | ||
1a62d0ac | 1568 | /* Forward the request to the BlockDriver, possibly fragmenting it */ |
c9d20029 KW |
1569 | total_bytes = bdrv_getlength(bs); |
1570 | if (total_bytes < 0) { | |
1571 | ret = total_bytes; | |
1572 | goto out; | |
1573 | } | |
61007b31 | 1574 | |
897dd0ec AS |
1575 | assert(!(flags & ~bs->supported_read_flags)); |
1576 | ||
c9d20029 | 1577 | max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align); |
1a62d0ac | 1578 | if (bytes <= max_bytes && bytes <= max_transfer) { |
897dd0ec | 1579 | ret = bdrv_driver_preadv(bs, offset, bytes, qiov, qiov_offset, flags); |
1a62d0ac EB |
1580 | goto out; |
1581 | } | |
61007b31 | 1582 | |
1a62d0ac | 1583 | while (bytes_remaining) { |
8b0c5d76 | 1584 | int64_t num; |
61007b31 | 1585 | |
1a62d0ac | 1586 | if (max_bytes) { |
1a62d0ac EB |
1587 | num = MIN(bytes_remaining, MIN(max_bytes, max_transfer)); |
1588 | assert(num); | |
61007b31 | 1589 | |
1a62d0ac | 1590 | ret = bdrv_driver_preadv(bs, offset + bytes - bytes_remaining, |
134b7dec | 1591 | num, qiov, |
897dd0ec AS |
1592 | qiov_offset + bytes - bytes_remaining, |
1593 | flags); | |
1a62d0ac | 1594 | max_bytes -= num; |
1a62d0ac EB |
1595 | } else { |
1596 | num = bytes_remaining; | |
134b7dec HR |
1597 | ret = qemu_iovec_memset(qiov, qiov_offset + bytes - bytes_remaining, |
1598 | 0, bytes_remaining); | |
1a62d0ac EB |
1599 | } |
1600 | if (ret < 0) { | |
1601 | goto out; | |
1602 | } | |
1603 | bytes_remaining -= num; | |
61007b31 SH |
1604 | } |
1605 | ||
1606 | out: | |
1a62d0ac | 1607 | return ret < 0 ? ret : 0; |
61007b31 SH |
1608 | } |
1609 | ||
61007b31 | 1610 | /* |
7a3f542f VSO |
1611 | * Request padding |
1612 | * | |
1613 | * |<---- align ----->| |<----- align ---->| | |
1614 | * |<- head ->|<------------- bytes ------------->|<-- tail -->| | |
1615 | * | | | | | | | |
1616 | * -*----------$-------*-------- ... --------*-----$------------*--- | |
1617 | * | | | | | | | |
1618 | * | offset | | end | | |
1619 | * ALIGN_DOWN(offset) ALIGN_UP(offset) ALIGN_DOWN(end) ALIGN_UP(end) | |
1620 | * [buf ... ) [tail_buf ) | |
1621 | * | |
1622 | * @buf is an aligned allocation needed to store @head and @tail paddings. @head | |
1623 | * is placed at the beginning of @buf and @tail at the @end. | |
1624 | * | |
1625 | * @tail_buf is a pointer to sub-buffer, corresponding to align-sized chunk | |
1626 | * around tail, if tail exists. | |
1627 | * | |
1628 | * @merge_reads is true for small requests, | |
1629 | * if @buf_len == @head + bytes + @tail. In this case it is possible that both | |
1630 | * head and tail exist but @buf_len == align and @tail_buf == @buf. | |
1631 | */ | |
1632 | typedef struct BdrvRequestPadding { | |
1633 | uint8_t *buf; | |
1634 | size_t buf_len; | |
1635 | uint8_t *tail_buf; | |
1636 | size_t head; | |
1637 | size_t tail; | |
1638 | bool merge_reads; | |
1639 | QEMUIOVector local_qiov; | |
1640 | } BdrvRequestPadding; | |
1641 | ||
1642 | static bool bdrv_init_padding(BlockDriverState *bs, | |
1643 | int64_t offset, int64_t bytes, | |
1644 | BdrvRequestPadding *pad) | |
1645 | { | |
a56ed80c VSO |
1646 | int64_t align = bs->bl.request_alignment; |
1647 | int64_t sum; | |
1648 | ||
1649 | bdrv_check_request(offset, bytes, &error_abort); | |
1650 | assert(align <= INT_MAX); /* documented in block/block_int.h */ | |
1651 | assert(align <= SIZE_MAX / 2); /* so we can allocate the buffer */ | |
7a3f542f VSO |
1652 | |
1653 | memset(pad, 0, sizeof(*pad)); | |
1654 | ||
1655 | pad->head = offset & (align - 1); | |
1656 | pad->tail = ((offset + bytes) & (align - 1)); | |
1657 | if (pad->tail) { | |
1658 | pad->tail = align - pad->tail; | |
1659 | } | |
1660 | ||
ac9d00bf | 1661 | if (!pad->head && !pad->tail) { |
7a3f542f VSO |
1662 | return false; |
1663 | } | |
1664 | ||
ac9d00bf VSO |
1665 | assert(bytes); /* Nothing good in aligning zero-length requests */ |
1666 | ||
7a3f542f VSO |
1667 | sum = pad->head + bytes + pad->tail; |
1668 | pad->buf_len = (sum > align && pad->head && pad->tail) ? 2 * align : align; | |
1669 | pad->buf = qemu_blockalign(bs, pad->buf_len); | |
1670 | pad->merge_reads = sum == pad->buf_len; | |
1671 | if (pad->tail) { | |
1672 | pad->tail_buf = pad->buf + pad->buf_len - align; | |
1673 | } | |
1674 | ||
1675 | return true; | |
1676 | } | |
1677 | ||
1678 | static int bdrv_padding_rmw_read(BdrvChild *child, | |
1679 | BdrvTrackedRequest *req, | |
1680 | BdrvRequestPadding *pad, | |
1681 | bool zero_middle) | |
1682 | { | |
1683 | QEMUIOVector local_qiov; | |
1684 | BlockDriverState *bs = child->bs; | |
1685 | uint64_t align = bs->bl.request_alignment; | |
1686 | int ret; | |
1687 | ||
1688 | assert(req->serialising && pad->buf); | |
1689 | ||
1690 | if (pad->head || pad->merge_reads) { | |
8b0c5d76 | 1691 | int64_t bytes = pad->merge_reads ? pad->buf_len : align; |
7a3f542f VSO |
1692 | |
1693 | qemu_iovec_init_buf(&local_qiov, pad->buf, bytes); | |
1694 | ||
1695 | if (pad->head) { | |
1696 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); | |
1697 | } | |
1698 | if (pad->merge_reads && pad->tail) { | |
1699 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); | |
1700 | } | |
1701 | ret = bdrv_aligned_preadv(child, req, req->overlap_offset, bytes, | |
65cd4424 | 1702 | align, &local_qiov, 0, 0); |
7a3f542f VSO |
1703 | if (ret < 0) { |
1704 | return ret; | |
1705 | } | |
1706 | if (pad->head) { | |
1707 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); | |
1708 | } | |
1709 | if (pad->merge_reads && pad->tail) { | |
1710 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); | |
1711 | } | |
1712 | ||
1713 | if (pad->merge_reads) { | |
1714 | goto zero_mem; | |
1715 | } | |
1716 | } | |
1717 | ||
1718 | if (pad->tail) { | |
1719 | qemu_iovec_init_buf(&local_qiov, pad->tail_buf, align); | |
1720 | ||
1721 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); | |
1722 | ret = bdrv_aligned_preadv( | |
1723 | child, req, | |
1724 | req->overlap_offset + req->overlap_bytes - align, | |
65cd4424 | 1725 | align, align, &local_qiov, 0, 0); |
7a3f542f VSO |
1726 | if (ret < 0) { |
1727 | return ret; | |
1728 | } | |
1729 | bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); | |
1730 | } | |
1731 | ||
1732 | zero_mem: | |
1733 | if (zero_middle) { | |
1734 | memset(pad->buf + pad->head, 0, pad->buf_len - pad->head - pad->tail); | |
1735 | } | |
1736 | ||
1737 | return 0; | |
1738 | } | |
1739 | ||
1740 | static void bdrv_padding_destroy(BdrvRequestPadding *pad) | |
1741 | { | |
1742 | if (pad->buf) { | |
1743 | qemu_vfree(pad->buf); | |
1744 | qemu_iovec_destroy(&pad->local_qiov); | |
1745 | } | |
98ca4549 | 1746 | memset(pad, 0, sizeof(*pad)); |
7a3f542f VSO |
1747 | } |
1748 | ||
1749 | /* | |
1750 | * bdrv_pad_request | |
1751 | * | |
1752 | * Exchange request parameters with padded request if needed. Don't include RMW | |
1753 | * read of padding, bdrv_padding_rmw_read() should be called separately if | |
1754 | * needed. | |
1755 | * | |
98ca4549 VSO |
1756 | * Request parameters (@qiov, &qiov_offset, &offset, &bytes) are in-out: |
1757 | * - on function start they represent original request | |
1758 | * - on failure or when padding is not needed they are unchanged | |
1759 | * - on success when padding is needed they represent padded request | |
61007b31 | 1760 | */ |
98ca4549 VSO |
1761 | static int bdrv_pad_request(BlockDriverState *bs, |
1762 | QEMUIOVector **qiov, size_t *qiov_offset, | |
37e9403e | 1763 | int64_t *offset, int64_t *bytes, |
98ca4549 | 1764 | BdrvRequestPadding *pad, bool *padded) |
7a3f542f | 1765 | { |
4c002cef VSO |
1766 | int ret; |
1767 | ||
37e9403e VSO |
1768 | bdrv_check_qiov_request(*offset, *bytes, *qiov, *qiov_offset, &error_abort); |
1769 | ||
7a3f542f | 1770 | if (!bdrv_init_padding(bs, *offset, *bytes, pad)) { |
98ca4549 VSO |
1771 | if (padded) { |
1772 | *padded = false; | |
1773 | } | |
1774 | return 0; | |
7a3f542f VSO |
1775 | } |
1776 | ||
4c002cef VSO |
1777 | ret = qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head, |
1778 | *qiov, *qiov_offset, *bytes, | |
1779 | pad->buf + pad->buf_len - pad->tail, | |
1780 | pad->tail); | |
98ca4549 VSO |
1781 | if (ret < 0) { |
1782 | bdrv_padding_destroy(pad); | |
1783 | return ret; | |
1784 | } | |
7a3f542f VSO |
1785 | *bytes += pad->head + pad->tail; |
1786 | *offset -= pad->head; | |
1787 | *qiov = &pad->local_qiov; | |
1acc3466 | 1788 | *qiov_offset = 0; |
98ca4549 VSO |
1789 | if (padded) { |
1790 | *padded = true; | |
1791 | } | |
7a3f542f | 1792 | |
98ca4549 | 1793 | return 0; |
7a3f542f VSO |
1794 | } |
1795 | ||
a03ef88f | 1796 | int coroutine_fn bdrv_co_preadv(BdrvChild *child, |
e9e52efd | 1797 | int64_t offset, int64_t bytes, QEMUIOVector *qiov, |
61007b31 | 1798 | BdrvRequestFlags flags) |
1acc3466 VSO |
1799 | { |
1800 | return bdrv_co_preadv_part(child, offset, bytes, qiov, 0, flags); | |
1801 | } | |
1802 | ||
1803 | int coroutine_fn bdrv_co_preadv_part(BdrvChild *child, | |
37e9403e | 1804 | int64_t offset, int64_t bytes, |
1acc3466 VSO |
1805 | QEMUIOVector *qiov, size_t qiov_offset, |
1806 | BdrvRequestFlags flags) | |
61007b31 | 1807 | { |
a03ef88f | 1808 | BlockDriverState *bs = child->bs; |
61007b31 | 1809 | BdrvTrackedRequest req; |
7a3f542f | 1810 | BdrvRequestPadding pad; |
61007b31 SH |
1811 | int ret; |
1812 | ||
37e9403e | 1813 | trace_bdrv_co_preadv_part(bs, offset, bytes, flags); |
61007b31 | 1814 | |
f4dad307 VSO |
1815 | if (!bdrv_is_inserted(bs)) { |
1816 | return -ENOMEDIUM; | |
1817 | } | |
1818 | ||
63f4ad11 | 1819 | ret = bdrv_check_request32(offset, bytes, qiov, qiov_offset); |
61007b31 SH |
1820 | if (ret < 0) { |
1821 | return ret; | |
1822 | } | |
1823 | ||
ac9d00bf VSO |
1824 | if (bytes == 0 && !QEMU_IS_ALIGNED(offset, bs->bl.request_alignment)) { |
1825 | /* | |
1826 | * Aligning zero request is nonsense. Even if driver has special meaning | |
1827 | * of zero-length (like qcow2_co_pwritev_compressed_part), we can't pass | |
1828 | * it to driver due to request_alignment. | |
1829 | * | |
1830 | * Still, no reason to return an error if someone do unaligned | |
1831 | * zero-length read occasionally. | |
1832 | */ | |
1833 | return 0; | |
1834 | } | |
1835 | ||
99723548 PB |
1836 | bdrv_inc_in_flight(bs); |
1837 | ||
9568b511 | 1838 | /* Don't do copy-on-read if we read data before write operation */ |
d73415a3 | 1839 | if (qatomic_read(&bs->copy_on_read)) { |
61007b31 SH |
1840 | flags |= BDRV_REQ_COPY_ON_READ; |
1841 | } | |
1842 | ||
98ca4549 VSO |
1843 | ret = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad, |
1844 | NULL); | |
1845 | if (ret < 0) { | |
87ab8802 | 1846 | goto fail; |
98ca4549 | 1847 | } |
61007b31 | 1848 | |
ebde595c | 1849 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ); |
7a3f542f VSO |
1850 | ret = bdrv_aligned_preadv(child, &req, offset, bytes, |
1851 | bs->bl.request_alignment, | |
1acc3466 | 1852 | qiov, qiov_offset, flags); |
61007b31 | 1853 | tracked_request_end(&req); |
7a3f542f | 1854 | bdrv_padding_destroy(&pad); |
61007b31 | 1855 | |
87ab8802 KW |
1856 | fail: |
1857 | bdrv_dec_in_flight(bs); | |
1858 | ||
61007b31 SH |
1859 | return ret; |
1860 | } | |
1861 | ||
d05aa8bb | 1862 | static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, |
5ae07b14 | 1863 | int64_t offset, int64_t bytes, BdrvRequestFlags flags) |
61007b31 SH |
1864 | { |
1865 | BlockDriver *drv = bs->drv; | |
1866 | QEMUIOVector qiov; | |
0d93ed08 | 1867 | void *buf = NULL; |
61007b31 | 1868 | int ret = 0; |
465fe887 | 1869 | bool need_flush = false; |
443668ca DL |
1870 | int head = 0; |
1871 | int tail = 0; | |
61007b31 | 1872 | |
2aaa3f9b VSO |
1873 | int64_t max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, |
1874 | INT64_MAX); | |
a5b8dd2c EB |
1875 | int alignment = MAX(bs->bl.pwrite_zeroes_alignment, |
1876 | bs->bl.request_alignment); | |
cb2e2878 | 1877 | int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, MAX_BOUNCE_BUFFER); |
d05aa8bb | 1878 | |
5ae07b14 VSO |
1879 | bdrv_check_request(offset, bytes, &error_abort); |
1880 | ||
d470ad42 HR |
1881 | if (!drv) { |
1882 | return -ENOMEDIUM; | |
1883 | } | |
1884 | ||
fe0480d6 KW |
1885 | if ((flags & ~bs->supported_zero_flags) & BDRV_REQ_NO_FALLBACK) { |
1886 | return -ENOTSUP; | |
1887 | } | |
1888 | ||
0bc329fb HR |
1889 | /* Invalidate the cached block-status data range if this write overlaps */ |
1890 | bdrv_bsc_invalidate_range(bs, offset, bytes); | |
1891 | ||
b8d0a980 EB |
1892 | assert(alignment % bs->bl.request_alignment == 0); |
1893 | head = offset % alignment; | |
f5a5ca79 | 1894 | tail = (offset + bytes) % alignment; |
b8d0a980 EB |
1895 | max_write_zeroes = QEMU_ALIGN_DOWN(max_write_zeroes, alignment); |
1896 | assert(max_write_zeroes >= bs->bl.request_alignment); | |
61007b31 | 1897 | |
f5a5ca79 | 1898 | while (bytes > 0 && !ret) { |
5ae07b14 | 1899 | int64_t num = bytes; |
61007b31 SH |
1900 | |
1901 | /* Align request. Block drivers can expect the "bulk" of the request | |
443668ca DL |
1902 | * to be aligned, and that unaligned requests do not cross cluster |
1903 | * boundaries. | |
61007b31 | 1904 | */ |
443668ca | 1905 | if (head) { |
b2f95fee EB |
1906 | /* Make a small request up to the first aligned sector. For |
1907 | * convenience, limit this request to max_transfer even if | |
1908 | * we don't need to fall back to writes. */ | |
f5a5ca79 | 1909 | num = MIN(MIN(bytes, max_transfer), alignment - head); |
b2f95fee EB |
1910 | head = (head + num) % alignment; |
1911 | assert(num < max_write_zeroes); | |
d05aa8bb | 1912 | } else if (tail && num > alignment) { |
443668ca DL |
1913 | /* Shorten the request to the last aligned sector. */ |
1914 | num -= tail; | |
61007b31 SH |
1915 | } |
1916 | ||
1917 | /* limit request size */ | |
1918 | if (num > max_write_zeroes) { | |
1919 | num = max_write_zeroes; | |
1920 | } | |
1921 | ||
1922 | ret = -ENOTSUP; | |
1923 | /* First try the efficient write zeroes operation */ | |
d05aa8bb EB |
1924 | if (drv->bdrv_co_pwrite_zeroes) { |
1925 | ret = drv->bdrv_co_pwrite_zeroes(bs, offset, num, | |
1926 | flags & bs->supported_zero_flags); | |
1927 | if (ret != -ENOTSUP && (flags & BDRV_REQ_FUA) && | |
1928 | !(bs->supported_zero_flags & BDRV_REQ_FUA)) { | |
1929 | need_flush = true; | |
1930 | } | |
465fe887 EB |
1931 | } else { |
1932 | assert(!bs->supported_zero_flags); | |
61007b31 SH |
1933 | } |
1934 | ||
294682cc | 1935 | if (ret == -ENOTSUP && !(flags & BDRV_REQ_NO_FALLBACK)) { |
61007b31 | 1936 | /* Fall back to bounce buffer if write zeroes is unsupported */ |
465fe887 EB |
1937 | BdrvRequestFlags write_flags = flags & ~BDRV_REQ_ZERO_WRITE; |
1938 | ||
1939 | if ((flags & BDRV_REQ_FUA) && | |
1940 | !(bs->supported_write_flags & BDRV_REQ_FUA)) { | |
1941 | /* No need for bdrv_driver_pwrite() to do a fallback | |
1942 | * flush on each chunk; use just one at the end */ | |
1943 | write_flags &= ~BDRV_REQ_FUA; | |
1944 | need_flush = true; | |
1945 | } | |
5def6b80 | 1946 | num = MIN(num, max_transfer); |
0d93ed08 VSO |
1947 | if (buf == NULL) { |
1948 | buf = qemu_try_blockalign0(bs, num); | |
1949 | if (buf == NULL) { | |
61007b31 SH |
1950 | ret = -ENOMEM; |
1951 | goto fail; | |
1952 | } | |
61007b31 | 1953 | } |
0d93ed08 | 1954 | qemu_iovec_init_buf(&qiov, buf, num); |
61007b31 | 1955 | |
ac850bf0 | 1956 | ret = bdrv_driver_pwritev(bs, offset, num, &qiov, 0, write_flags); |
61007b31 SH |
1957 | |
1958 | /* Keep bounce buffer around if it is big enough for all | |
1959 | * all future requests. | |
1960 | */ | |
5def6b80 | 1961 | if (num < max_transfer) { |
0d93ed08 VSO |
1962 | qemu_vfree(buf); |
1963 | buf = NULL; | |
61007b31 SH |
1964 | } |
1965 | } | |
1966 | ||
d05aa8bb | 1967 | offset += num; |
f5a5ca79 | 1968 | bytes -= num; |
61007b31 SH |
1969 | } |
1970 | ||
1971 | fail: | |
465fe887 EB |
1972 | if (ret == 0 && need_flush) { |
1973 | ret = bdrv_co_flush(bs); | |
1974 | } | |
0d93ed08 | 1975 | qemu_vfree(buf); |
61007b31 SH |
1976 | return ret; |
1977 | } | |
1978 | ||
85fe2479 | 1979 | static inline int coroutine_fn |
fcfd9ade | 1980 | bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, int64_t bytes, |
85fe2479 FZ |
1981 | BdrvTrackedRequest *req, int flags) |
1982 | { | |
1983 | BlockDriverState *bs = child->bs; | |
fcfd9ade VSO |
1984 | |
1985 | bdrv_check_request(offset, bytes, &error_abort); | |
85fe2479 | 1986 | |
307261b2 | 1987 | if (bdrv_is_read_only(bs)) { |
85fe2479 FZ |
1988 | return -EPERM; |
1989 | } | |
1990 | ||
85fe2479 FZ |
1991 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); |
1992 | assert((bs->open_flags & BDRV_O_NO_IO) == 0); | |
1993 | assert(!(flags & ~BDRV_REQ_MASK)); | |
d1a764d1 | 1994 | assert(!((flags & BDRV_REQ_NO_WAIT) && !(flags & BDRV_REQ_SERIALISING))); |
85fe2479 FZ |
1995 | |
1996 | if (flags & BDRV_REQ_SERIALISING) { | |
d1a764d1 VSO |
1997 | QEMU_LOCK_GUARD(&bs->reqs_lock); |
1998 | ||
1999 | tracked_request_set_serialising(req, bdrv_get_cluster_size(bs)); | |
2000 | ||
2001 | if ((flags & BDRV_REQ_NO_WAIT) && bdrv_find_conflicting_request(req)) { | |
2002 | return -EBUSY; | |
2003 | } | |
2004 | ||
2005 | bdrv_wait_serialising_requests_locked(req); | |
18fbd0de PB |
2006 | } else { |
2007 | bdrv_wait_serialising_requests(req); | |
85fe2479 FZ |
2008 | } |
2009 | ||
85fe2479 FZ |
2010 | assert(req->overlap_offset <= offset); |
2011 | assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); | |
fcfd9ade VSO |
2012 | assert(offset + bytes <= bs->total_sectors * BDRV_SECTOR_SIZE || |
2013 | child->perm & BLK_PERM_RESIZE); | |
85fe2479 | 2014 | |
cd47d792 FZ |
2015 | switch (req->type) { |
2016 | case BDRV_TRACKED_WRITE: | |
2017 | case BDRV_TRACKED_DISCARD: | |
2018 | if (flags & BDRV_REQ_WRITE_UNCHANGED) { | |
2019 | assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE)); | |
2020 | } else { | |
2021 | assert(child->perm & BLK_PERM_WRITE); | |
2022 | } | |
94783301 VSO |
2023 | bdrv_write_threshold_check_write(bs, offset, bytes); |
2024 | return 0; | |
cd47d792 FZ |
2025 | case BDRV_TRACKED_TRUNCATE: |
2026 | assert(child->perm & BLK_PERM_RESIZE); | |
2027 | return 0; | |
2028 | default: | |
2029 | abort(); | |
85fe2479 | 2030 | } |
85fe2479 FZ |
2031 | } |
2032 | ||
2033 | static inline void coroutine_fn | |
fcfd9ade | 2034 | bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, int64_t bytes, |
85fe2479 FZ |
2035 | BdrvTrackedRequest *req, int ret) |
2036 | { | |
2037 | int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE); | |
2038 | BlockDriverState *bs = child->bs; | |
2039 | ||
fcfd9ade VSO |
2040 | bdrv_check_request(offset, bytes, &error_abort); |
2041 | ||
d73415a3 | 2042 | qatomic_inc(&bs->write_gen); |
85fe2479 | 2043 | |
00695c27 FZ |
2044 | /* |
2045 | * Discard cannot extend the image, but in error handling cases, such as | |
2046 | * when reverting a qcow2 cluster allocation, the discarded range can pass | |
2047 | * the end of image file, so we cannot assert about BDRV_TRACKED_DISCARD | |
2048 | * here. Instead, just skip it, since semantically a discard request | |
2049 | * beyond EOF cannot expand the image anyway. | |
2050 | */ | |
7f8f03ef | 2051 | if (ret == 0 && |
cd47d792 FZ |
2052 | (req->type == BDRV_TRACKED_TRUNCATE || |
2053 | end_sector > bs->total_sectors) && | |
2054 | req->type != BDRV_TRACKED_DISCARD) { | |
7f8f03ef FZ |
2055 | bs->total_sectors = end_sector; |
2056 | bdrv_parent_cb_resize(bs); | |
2057 | bdrv_dirty_bitmap_truncate(bs, end_sector << BDRV_SECTOR_BITS); | |
85fe2479 | 2058 | } |
00695c27 FZ |
2059 | if (req->bytes) { |
2060 | switch (req->type) { | |
2061 | case BDRV_TRACKED_WRITE: | |
2062 | stat64_max(&bs->wr_highest_offset, offset + bytes); | |
2063 | /* fall through, to set dirty bits */ | |
2064 | case BDRV_TRACKED_DISCARD: | |
2065 | bdrv_set_dirty(bs, offset, bytes); | |
2066 | break; | |
2067 | default: | |
2068 | break; | |
2069 | } | |
2070 | } | |
85fe2479 FZ |
2071 | } |
2072 | ||
61007b31 | 2073 | /* |
04ed95f4 EB |
2074 | * Forwards an already correctly aligned write request to the BlockDriver, |
2075 | * after possibly fragmenting it. | |
61007b31 | 2076 | */ |
85c97ca7 | 2077 | static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child, |
fcfd9ade | 2078 | BdrvTrackedRequest *req, int64_t offset, int64_t bytes, |
e75abeda VSO |
2079 | int64_t align, QEMUIOVector *qiov, size_t qiov_offset, |
2080 | BdrvRequestFlags flags) | |
61007b31 | 2081 | { |
85c97ca7 | 2082 | BlockDriverState *bs = child->bs; |
61007b31 | 2083 | BlockDriver *drv = bs->drv; |
61007b31 SH |
2084 | int ret; |
2085 | ||
fcfd9ade | 2086 | int64_t bytes_remaining = bytes; |
04ed95f4 | 2087 | int max_transfer; |
61007b31 | 2088 | |
fcfd9ade VSO |
2089 | bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort); |
2090 | ||
d470ad42 HR |
2091 | if (!drv) { |
2092 | return -ENOMEDIUM; | |
2093 | } | |
2094 | ||
d6883bc9 VSO |
2095 | if (bdrv_has_readonly_bitmaps(bs)) { |
2096 | return -EPERM; | |
2097 | } | |
2098 | ||
cff86b38 EB |
2099 | assert(is_power_of_2(align)); |
2100 | assert((offset & (align - 1)) == 0); | |
2101 | assert((bytes & (align - 1)) == 0); | |
04ed95f4 EB |
2102 | max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX), |
2103 | align); | |
61007b31 | 2104 | |
85fe2479 | 2105 | ret = bdrv_co_write_req_prepare(child, offset, bytes, req, flags); |
61007b31 SH |
2106 | |
2107 | if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF && | |
c1499a5e | 2108 | !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_pwrite_zeroes && |
28c4da28 | 2109 | qemu_iovec_is_zero(qiov, qiov_offset, bytes)) { |
61007b31 SH |
2110 | flags |= BDRV_REQ_ZERO_WRITE; |
2111 | if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) { | |
2112 | flags |= BDRV_REQ_MAY_UNMAP; | |
2113 | } | |
2114 | } | |
2115 | ||
2116 | if (ret < 0) { | |
2117 | /* Do nothing, write notifier decided to fail this request */ | |
2118 | } else if (flags & BDRV_REQ_ZERO_WRITE) { | |
9a4f4c31 | 2119 | bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO); |
9896c876 | 2120 | ret = bdrv_co_do_pwrite_zeroes(bs, offset, bytes, flags); |
3ea1a091 | 2121 | } else if (flags & BDRV_REQ_WRITE_COMPRESSED) { |
28c4da28 VSO |
2122 | ret = bdrv_driver_pwritev_compressed(bs, offset, bytes, |
2123 | qiov, qiov_offset); | |
04ed95f4 | 2124 | } else if (bytes <= max_transfer) { |
9a4f4c31 | 2125 | bdrv_debug_event(bs, BLKDBG_PWRITEV); |
28c4da28 | 2126 | ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, qiov_offset, flags); |
04ed95f4 EB |
2127 | } else { |
2128 | bdrv_debug_event(bs, BLKDBG_PWRITEV); | |
2129 | while (bytes_remaining) { | |
2130 | int num = MIN(bytes_remaining, max_transfer); | |
04ed95f4 EB |
2131 | int local_flags = flags; |
2132 | ||
2133 | assert(num); | |
2134 | if (num < bytes_remaining && (flags & BDRV_REQ_FUA) && | |
2135 | !(bs->supported_write_flags & BDRV_REQ_FUA)) { | |
2136 | /* If FUA is going to be emulated by flush, we only | |
2137 | * need to flush on the last iteration */ | |
2138 | local_flags &= ~BDRV_REQ_FUA; | |
2139 | } | |
04ed95f4 EB |
2140 | |
2141 | ret = bdrv_driver_pwritev(bs, offset + bytes - bytes_remaining, | |
134b7dec HR |
2142 | num, qiov, |
2143 | qiov_offset + bytes - bytes_remaining, | |
28c4da28 | 2144 | local_flags); |
04ed95f4 EB |
2145 | if (ret < 0) { |
2146 | break; | |
2147 | } | |
2148 | bytes_remaining -= num; | |
2149 | } | |
61007b31 | 2150 | } |
9a4f4c31 | 2151 | bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE); |
61007b31 | 2152 | |
61007b31 | 2153 | if (ret >= 0) { |
04ed95f4 | 2154 | ret = 0; |
61007b31 | 2155 | } |
85fe2479 | 2156 | bdrv_co_write_req_finish(child, offset, bytes, req, ret); |
61007b31 SH |
2157 | |
2158 | return ret; | |
2159 | } | |
2160 | ||
85c97ca7 | 2161 | static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child, |
9eeb6dd1 | 2162 | int64_t offset, |
37e9403e | 2163 | int64_t bytes, |
9eeb6dd1 FZ |
2164 | BdrvRequestFlags flags, |
2165 | BdrvTrackedRequest *req) | |
2166 | { | |
85c97ca7 | 2167 | BlockDriverState *bs = child->bs; |
9eeb6dd1 | 2168 | QEMUIOVector local_qiov; |
a5b8dd2c | 2169 | uint64_t align = bs->bl.request_alignment; |
9eeb6dd1 | 2170 | int ret = 0; |
7a3f542f VSO |
2171 | bool padding; |
2172 | BdrvRequestPadding pad; | |
9eeb6dd1 | 2173 | |
7a3f542f VSO |
2174 | padding = bdrv_init_padding(bs, offset, bytes, &pad); |
2175 | if (padding) { | |
8ac5aab2 | 2176 | bdrv_make_request_serialising(req, align); |
9eeb6dd1 | 2177 | |
7a3f542f VSO |
2178 | bdrv_padding_rmw_read(child, req, &pad, true); |
2179 | ||
2180 | if (pad.head || pad.merge_reads) { | |
2181 | int64_t aligned_offset = offset & ~(align - 1); | |
2182 | int64_t write_bytes = pad.merge_reads ? pad.buf_len : align; | |
2183 | ||
2184 | qemu_iovec_init_buf(&local_qiov, pad.buf, write_bytes); | |
2185 | ret = bdrv_aligned_pwritev(child, req, aligned_offset, write_bytes, | |
28c4da28 | 2186 | align, &local_qiov, 0, |
7a3f542f VSO |
2187 | flags & ~BDRV_REQ_ZERO_WRITE); |
2188 | if (ret < 0 || pad.merge_reads) { | |
2189 | /* Error or all work is done */ | |
2190 | goto out; | |
2191 | } | |
2192 | offset += write_bytes - pad.head; | |
2193 | bytes -= write_bytes - pad.head; | |
9eeb6dd1 | 2194 | } |
9eeb6dd1 FZ |
2195 | } |
2196 | ||
2197 | assert(!bytes || (offset & (align - 1)) == 0); | |
2198 | if (bytes >= align) { | |
2199 | /* Write the aligned part in the middle. */ | |
fcfd9ade | 2200 | int64_t aligned_bytes = bytes & ~(align - 1); |
85c97ca7 | 2201 | ret = bdrv_aligned_pwritev(child, req, offset, aligned_bytes, align, |
28c4da28 | 2202 | NULL, 0, flags); |
9eeb6dd1 | 2203 | if (ret < 0) { |
7a3f542f | 2204 | goto out; |
9eeb6dd1 FZ |
2205 | } |
2206 | bytes -= aligned_bytes; | |
2207 | offset += aligned_bytes; | |
2208 | } | |
2209 | ||
2210 | assert(!bytes || (offset & (align - 1)) == 0); | |
2211 | if (bytes) { | |
7a3f542f | 2212 | assert(align == pad.tail + bytes); |
9eeb6dd1 | 2213 | |
7a3f542f | 2214 | qemu_iovec_init_buf(&local_qiov, pad.tail_buf, align); |
85c97ca7 | 2215 | ret = bdrv_aligned_pwritev(child, req, offset, align, align, |
28c4da28 VSO |
2216 | &local_qiov, 0, |
2217 | flags & ~BDRV_REQ_ZERO_WRITE); | |
9eeb6dd1 | 2218 | } |
9eeb6dd1 | 2219 | |
7a3f542f VSO |
2220 | out: |
2221 | bdrv_padding_destroy(&pad); | |
2222 | ||
2223 | return ret; | |
9eeb6dd1 FZ |
2224 | } |
2225 | ||
61007b31 SH |
2226 | /* |
2227 | * Handle a write request in coroutine context | |
2228 | */ | |
a03ef88f | 2229 | int coroutine_fn bdrv_co_pwritev(BdrvChild *child, |
e9e52efd | 2230 | int64_t offset, int64_t bytes, QEMUIOVector *qiov, |
61007b31 | 2231 | BdrvRequestFlags flags) |
1acc3466 VSO |
2232 | { |
2233 | return bdrv_co_pwritev_part(child, offset, bytes, qiov, 0, flags); | |
2234 | } | |
2235 | ||
2236 | int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child, | |
37e9403e | 2237 | int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset, |
1acc3466 | 2238 | BdrvRequestFlags flags) |
61007b31 | 2239 | { |
a03ef88f | 2240 | BlockDriverState *bs = child->bs; |
61007b31 | 2241 | BdrvTrackedRequest req; |
a5b8dd2c | 2242 | uint64_t align = bs->bl.request_alignment; |
7a3f542f | 2243 | BdrvRequestPadding pad; |
61007b31 | 2244 | int ret; |
f0deecff | 2245 | bool padded = false; |
61007b31 | 2246 | |
37e9403e | 2247 | trace_bdrv_co_pwritev_part(child->bs, offset, bytes, flags); |
f42cf447 | 2248 | |
f4dad307 | 2249 | if (!bdrv_is_inserted(bs)) { |
61007b31 SH |
2250 | return -ENOMEDIUM; |
2251 | } | |
61007b31 | 2252 | |
2aaa3f9b VSO |
2253 | if (flags & BDRV_REQ_ZERO_WRITE) { |
2254 | ret = bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, NULL); | |
2255 | } else { | |
2256 | ret = bdrv_check_request32(offset, bytes, qiov, qiov_offset); | |
2257 | } | |
61007b31 SH |
2258 | if (ret < 0) { |
2259 | return ret; | |
2260 | } | |
2261 | ||
f2208fdc AG |
2262 | /* If the request is misaligned then we can't make it efficient */ |
2263 | if ((flags & BDRV_REQ_NO_FALLBACK) && | |
2264 | !QEMU_IS_ALIGNED(offset | bytes, align)) | |
2265 | { | |
2266 | return -ENOTSUP; | |
2267 | } | |
2268 | ||
ac9d00bf VSO |
2269 | if (bytes == 0 && !QEMU_IS_ALIGNED(offset, bs->bl.request_alignment)) { |
2270 | /* | |
2271 | * Aligning zero request is nonsense. Even if driver has special meaning | |
2272 | * of zero-length (like qcow2_co_pwritev_compressed_part), we can't pass | |
2273 | * it to driver due to request_alignment. | |
2274 | * | |
2275 | * Still, no reason to return an error if someone do unaligned | |
2276 | * zero-length write occasionally. | |
2277 | */ | |
2278 | return 0; | |
2279 | } | |
2280 | ||
f0deecff VSO |
2281 | if (!(flags & BDRV_REQ_ZERO_WRITE)) { |
2282 | /* | |
2283 | * Pad request for following read-modify-write cycle. | |
2284 | * bdrv_co_do_zero_pwritev() does aligning by itself, so, we do | |
2285 | * alignment only if there is no ZERO flag. | |
2286 | */ | |
98ca4549 VSO |
2287 | ret = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad, |
2288 | &padded); | |
2289 | if (ret < 0) { | |
2290 | return ret; | |
2291 | } | |
f0deecff VSO |
2292 | } |
2293 | ||
99723548 | 2294 | bdrv_inc_in_flight(bs); |
ebde595c | 2295 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE); |
61007b31 | 2296 | |
18a59f03 | 2297 | if (flags & BDRV_REQ_ZERO_WRITE) { |
f0deecff | 2298 | assert(!padded); |
85c97ca7 | 2299 | ret = bdrv_co_do_zero_pwritev(child, offset, bytes, flags, &req); |
9eeb6dd1 FZ |
2300 | goto out; |
2301 | } | |
2302 | ||
f0deecff VSO |
2303 | if (padded) { |
2304 | /* | |
2305 | * Request was unaligned to request_alignment and therefore | |
2306 | * padded. We are going to do read-modify-write, and must | |
2307 | * serialize the request to prevent interactions of the | |
2308 | * widened region with other transactions. | |
2309 | */ | |
8ac5aab2 | 2310 | bdrv_make_request_serialising(&req, align); |
7a3f542f | 2311 | bdrv_padding_rmw_read(child, &req, &pad, false); |
61007b31 SH |
2312 | } |
2313 | ||
85c97ca7 | 2314 | ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align, |
1acc3466 | 2315 | qiov, qiov_offset, flags); |
61007b31 | 2316 | |
7a3f542f | 2317 | bdrv_padding_destroy(&pad); |
61007b31 | 2318 | |
9eeb6dd1 FZ |
2319 | out: |
2320 | tracked_request_end(&req); | |
99723548 | 2321 | bdrv_dec_in_flight(bs); |
7a3f542f | 2322 | |
61007b31 SH |
2323 | return ret; |
2324 | } | |
2325 | ||
a03ef88f | 2326 | int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, |
e9e52efd | 2327 | int64_t bytes, BdrvRequestFlags flags) |
61007b31 | 2328 | { |
f5a5ca79 | 2329 | trace_bdrv_co_pwrite_zeroes(child->bs, offset, bytes, flags); |
61007b31 | 2330 | |
a03ef88f | 2331 | if (!(child->bs->open_flags & BDRV_O_UNMAP)) { |
61007b31 SH |
2332 | flags &= ~BDRV_REQ_MAY_UNMAP; |
2333 | } | |
61007b31 | 2334 | |
f5a5ca79 | 2335 | return bdrv_co_pwritev(child, offset, bytes, NULL, |
74021bc4 | 2336 | BDRV_REQ_ZERO_WRITE | flags); |
61007b31 SH |
2337 | } |
2338 | ||
4085f5c7 JS |
2339 | /* |
2340 | * Flush ALL BDSes regardless of if they are reachable via a BlkBackend or not. | |
2341 | */ | |
2342 | int bdrv_flush_all(void) | |
2343 | { | |
2344 | BdrvNextIterator it; | |
2345 | BlockDriverState *bs = NULL; | |
2346 | int result = 0; | |
2347 | ||
c8aa7895 PD |
2348 | /* |
2349 | * bdrv queue is managed by record/replay, | |
2350 | * creating new flush request for stopping | |
2351 | * the VM may break the determinism | |
2352 | */ | |
2353 | if (replay_events_enabled()) { | |
2354 | return result; | |
2355 | } | |
2356 | ||
4085f5c7 JS |
2357 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
2358 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2359 | int ret; | |
2360 | ||
2361 | aio_context_acquire(aio_context); | |
2362 | ret = bdrv_flush(bs); | |
2363 | if (ret < 0 && !result) { | |
2364 | result = ret; | |
2365 | } | |
2366 | aio_context_release(aio_context); | |
2367 | } | |
2368 | ||
2369 | return result; | |
2370 | } | |
2371 | ||
61007b31 SH |
2372 | /* |
2373 | * Returns the allocation status of the specified sectors. | |
2374 | * Drivers not implementing the functionality are assumed to not support | |
2375 | * backing files, hence all their sectors are reported as allocated. | |
2376 | * | |
86a3d5c6 EB |
2377 | * If 'want_zero' is true, the caller is querying for mapping |
2378 | * purposes, with a focus on valid BDRV_BLOCK_OFFSET_VALID, _DATA, and | |
2379 | * _ZERO where possible; otherwise, the result favors larger 'pnum', | |
2380 | * with a focus on accurate BDRV_BLOCK_ALLOCATED. | |
c9ce8c4d | 2381 | * |
2e8bc787 | 2382 | * If 'offset' is beyond the end of the disk image the return value is |
fb0d8654 | 2383 | * BDRV_BLOCK_EOF and 'pnum' is set to 0. |
61007b31 | 2384 | * |
2e8bc787 | 2385 | * 'bytes' is the max value 'pnum' should be set to. If bytes goes |
fb0d8654 EB |
2386 | * beyond the end of the disk image it will be clamped; if 'pnum' is set to |
2387 | * the end of the image, then the returned value will include BDRV_BLOCK_EOF. | |
67a0fd2a | 2388 | * |
2e8bc787 EB |
2389 | * 'pnum' is set to the number of bytes (including and immediately |
2390 | * following the specified offset) that are easily known to be in the | |
2391 | * same allocated/unallocated state. Note that a second call starting | |
2392 | * at the original offset plus returned pnum may have the same status. | |
2393 | * The returned value is non-zero on success except at end-of-file. | |
2394 | * | |
2395 | * Returns negative errno on failure. Otherwise, if the | |
2396 | * BDRV_BLOCK_OFFSET_VALID bit is set, 'map' and 'file' (if non-NULL) are | |
2397 | * set to the host mapping and BDS corresponding to the guest offset. | |
61007b31 | 2398 | */ |
2e8bc787 EB |
2399 | static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs, |
2400 | bool want_zero, | |
2401 | int64_t offset, int64_t bytes, | |
2402 | int64_t *pnum, int64_t *map, | |
2403 | BlockDriverState **file) | |
2404 | { | |
2405 | int64_t total_size; | |
2406 | int64_t n; /* bytes */ | |
efa6e2ed | 2407 | int ret; |
2e8bc787 | 2408 | int64_t local_map = 0; |
298a1665 | 2409 | BlockDriverState *local_file = NULL; |
efa6e2ed EB |
2410 | int64_t aligned_offset, aligned_bytes; |
2411 | uint32_t align; | |
549ec0d9 | 2412 | bool has_filtered_child; |
61007b31 | 2413 | |
298a1665 EB |
2414 | assert(pnum); |
2415 | *pnum = 0; | |
2e8bc787 EB |
2416 | total_size = bdrv_getlength(bs); |
2417 | if (total_size < 0) { | |
2418 | ret = total_size; | |
298a1665 | 2419 | goto early_out; |
61007b31 SH |
2420 | } |
2421 | ||
2e8bc787 | 2422 | if (offset >= total_size) { |
298a1665 EB |
2423 | ret = BDRV_BLOCK_EOF; |
2424 | goto early_out; | |
61007b31 | 2425 | } |
2e8bc787 | 2426 | if (!bytes) { |
298a1665 EB |
2427 | ret = 0; |
2428 | goto early_out; | |
9cdcfd9f | 2429 | } |
61007b31 | 2430 | |
2e8bc787 EB |
2431 | n = total_size - offset; |
2432 | if (n < bytes) { | |
2433 | bytes = n; | |
61007b31 SH |
2434 | } |
2435 | ||
d470ad42 HR |
2436 | /* Must be non-NULL or bdrv_getlength() would have failed */ |
2437 | assert(bs->drv); | |
549ec0d9 HR |
2438 | has_filtered_child = bdrv_filter_child(bs); |
2439 | if (!bs->drv->bdrv_co_block_status && !has_filtered_child) { | |
2e8bc787 | 2440 | *pnum = bytes; |
61007b31 | 2441 | ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED; |
2e8bc787 | 2442 | if (offset + bytes == total_size) { |
fb0d8654 EB |
2443 | ret |= BDRV_BLOCK_EOF; |
2444 | } | |
61007b31 | 2445 | if (bs->drv->protocol_name) { |
2e8bc787 EB |
2446 | ret |= BDRV_BLOCK_OFFSET_VALID; |
2447 | local_map = offset; | |
298a1665 | 2448 | local_file = bs; |
61007b31 | 2449 | } |
298a1665 | 2450 | goto early_out; |
61007b31 SH |
2451 | } |
2452 | ||
99723548 | 2453 | bdrv_inc_in_flight(bs); |
efa6e2ed EB |
2454 | |
2455 | /* Round out to request_alignment boundaries */ | |
86a3d5c6 | 2456 | align = bs->bl.request_alignment; |
efa6e2ed EB |
2457 | aligned_offset = QEMU_ALIGN_DOWN(offset, align); |
2458 | aligned_bytes = ROUND_UP(offset + bytes, align) - aligned_offset; | |
2459 | ||
549ec0d9 | 2460 | if (bs->drv->bdrv_co_block_status) { |
0bc329fb HR |
2461 | /* |
2462 | * Use the block-status cache only for protocol nodes: Format | |
2463 | * drivers are generally quick to inquire the status, but protocol | |
2464 | * drivers often need to get information from outside of qemu, so | |
2465 | * we do not have control over the actual implementation. There | |
2466 | * have been cases where inquiring the status took an unreasonably | |
2467 | * long time, and we can do nothing in qemu to fix it. | |
2468 | * This is especially problematic for images with large data areas, | |
2469 | * because finding the few holes in them and giving them special | |
2470 | * treatment does not gain much performance. Therefore, we try to | |
2471 | * cache the last-identified data region. | |
2472 | * | |
2473 | * Second, limiting ourselves to protocol nodes allows us to assume | |
2474 | * the block status for data regions to be DATA | OFFSET_VALID, and | |
2475 | * that the host offset is the same as the guest offset. | |
2476 | * | |
2477 | * Note that it is possible that external writers zero parts of | |
2478 | * the cached regions without the cache being invalidated, and so | |
2479 | * we may report zeroes as data. This is not catastrophic, | |
2480 | * however, because reporting zeroes as data is fine. | |
2481 | */ | |
2482 | if (QLIST_EMPTY(&bs->children) && | |
2483 | bdrv_bsc_is_data(bs, aligned_offset, pnum)) | |
2484 | { | |
2485 | ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; | |
2486 | local_file = bs; | |
2487 | local_map = aligned_offset; | |
2488 | } else { | |
2489 | ret = bs->drv->bdrv_co_block_status(bs, want_zero, aligned_offset, | |
2490 | aligned_bytes, pnum, &local_map, | |
2491 | &local_file); | |
2492 | ||
2493 | /* | |
2494 | * Note that checking QLIST_EMPTY(&bs->children) is also done when | |
2495 | * the cache is queried above. Technically, we do not need to check | |
2496 | * it here; the worst that can happen is that we fill the cache for | |
2497 | * non-protocol nodes, and then it is never used. However, filling | |
2498 | * the cache requires an RCU update, so double check here to avoid | |
2499 | * such an update if possible. | |
2500 | */ | |
2501 | if (ret == (BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID) && | |
2502 | QLIST_EMPTY(&bs->children)) | |
2503 | { | |
2504 | /* | |
2505 | * When a protocol driver reports BLOCK_OFFSET_VALID, the | |
2506 | * returned local_map value must be the same as the offset we | |
2507 | * have passed (aligned_offset), and local_bs must be the node | |
2508 | * itself. | |
2509 | * Assert this, because we follow this rule when reading from | |
2510 | * the cache (see the `local_file = bs` and | |
2511 | * `local_map = aligned_offset` assignments above), and the | |
2512 | * result the cache delivers must be the same as the driver | |
2513 | * would deliver. | |
2514 | */ | |
2515 | assert(local_file == bs); | |
2516 | assert(local_map == aligned_offset); | |
2517 | bdrv_bsc_fill(bs, aligned_offset, *pnum); | |
2518 | } | |
2519 | } | |
549ec0d9 HR |
2520 | } else { |
2521 | /* Default code for filters */ | |
2522 | ||
2523 | local_file = bdrv_filter_bs(bs); | |
2524 | assert(local_file); | |
2525 | ||
2526 | *pnum = aligned_bytes; | |
2527 | local_map = aligned_offset; | |
2528 | ret = BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID; | |
2529 | } | |
636cb512 EB |
2530 | if (ret < 0) { |
2531 | *pnum = 0; | |
2532 | goto out; | |
efa6e2ed EB |
2533 | } |
2534 | ||
2e8bc787 | 2535 | /* |
636cb512 | 2536 | * The driver's result must be a non-zero multiple of request_alignment. |
efa6e2ed | 2537 | * Clamp pnum and adjust map to original request. |
2e8bc787 | 2538 | */ |
636cb512 EB |
2539 | assert(*pnum && QEMU_IS_ALIGNED(*pnum, align) && |
2540 | align > offset - aligned_offset); | |
69f47505 VSO |
2541 | if (ret & BDRV_BLOCK_RECURSE) { |
2542 | assert(ret & BDRV_BLOCK_DATA); | |
2543 | assert(ret & BDRV_BLOCK_OFFSET_VALID); | |
2544 | assert(!(ret & BDRV_BLOCK_ZERO)); | |
2545 | } | |
2546 | ||
efa6e2ed EB |
2547 | *pnum -= offset - aligned_offset; |
2548 | if (*pnum > bytes) { | |
2549 | *pnum = bytes; | |
61007b31 | 2550 | } |
2e8bc787 | 2551 | if (ret & BDRV_BLOCK_OFFSET_VALID) { |
efa6e2ed | 2552 | local_map += offset - aligned_offset; |
2e8bc787 | 2553 | } |
61007b31 SH |
2554 | |
2555 | if (ret & BDRV_BLOCK_RAW) { | |
298a1665 | 2556 | assert(ret & BDRV_BLOCK_OFFSET_VALID && local_file); |
2e8bc787 EB |
2557 | ret = bdrv_co_block_status(local_file, want_zero, local_map, |
2558 | *pnum, pnum, &local_map, &local_file); | |
99723548 | 2559 | goto out; |
61007b31 SH |
2560 | } |
2561 | ||
2562 | if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { | |
2563 | ret |= BDRV_BLOCK_ALLOCATED; | |
d40f4a56 | 2564 | } else if (bs->drv->supports_backing) { |
cb850315 HR |
2565 | BlockDriverState *cow_bs = bdrv_cow_bs(bs); |
2566 | ||
d40f4a56 AG |
2567 | if (!cow_bs) { |
2568 | ret |= BDRV_BLOCK_ZERO; | |
2569 | } else if (want_zero) { | |
cb850315 | 2570 | int64_t size2 = bdrv_getlength(cow_bs); |
c9ce8c4d | 2571 | |
2e8bc787 | 2572 | if (size2 >= 0 && offset >= size2) { |
61007b31 SH |
2573 | ret |= BDRV_BLOCK_ZERO; |
2574 | } | |
2575 | } | |
2576 | } | |
2577 | ||
69f47505 VSO |
2578 | if (want_zero && ret & BDRV_BLOCK_RECURSE && |
2579 | local_file && local_file != bs && | |
61007b31 SH |
2580 | (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && |
2581 | (ret & BDRV_BLOCK_OFFSET_VALID)) { | |
2e8bc787 EB |
2582 | int64_t file_pnum; |
2583 | int ret2; | |
61007b31 | 2584 | |
2e8bc787 EB |
2585 | ret2 = bdrv_co_block_status(local_file, want_zero, local_map, |
2586 | *pnum, &file_pnum, NULL, NULL); | |
61007b31 SH |
2587 | if (ret2 >= 0) { |
2588 | /* Ignore errors. This is just providing extra information, it | |
2589 | * is useful but not necessary. | |
2590 | */ | |
c61e684e EB |
2591 | if (ret2 & BDRV_BLOCK_EOF && |
2592 | (!file_pnum || ret2 & BDRV_BLOCK_ZERO)) { | |
2593 | /* | |
2594 | * It is valid for the format block driver to read | |
2595 | * beyond the end of the underlying file's current | |
2596 | * size; such areas read as zero. | |
2597 | */ | |
61007b31 SH |
2598 | ret |= BDRV_BLOCK_ZERO; |
2599 | } else { | |
2600 | /* Limit request to the range reported by the protocol driver */ | |
2601 | *pnum = file_pnum; | |
2602 | ret |= (ret2 & BDRV_BLOCK_ZERO); | |
2603 | } | |
2604 | } | |
2605 | } | |
2606 | ||
99723548 PB |
2607 | out: |
2608 | bdrv_dec_in_flight(bs); | |
2e8bc787 | 2609 | if (ret >= 0 && offset + *pnum == total_size) { |
fb0d8654 EB |
2610 | ret |= BDRV_BLOCK_EOF; |
2611 | } | |
298a1665 EB |
2612 | early_out: |
2613 | if (file) { | |
2614 | *file = local_file; | |
2615 | } | |
2e8bc787 EB |
2616 | if (map) { |
2617 | *map = local_map; | |
2618 | } | |
61007b31 SH |
2619 | return ret; |
2620 | } | |
2621 | ||
21c2283e | 2622 | int coroutine_fn |
f9e694cb VSO |
2623 | bdrv_co_common_block_status_above(BlockDriverState *bs, |
2624 | BlockDriverState *base, | |
3555a432 | 2625 | bool include_base, |
f9e694cb VSO |
2626 | bool want_zero, |
2627 | int64_t offset, | |
2628 | int64_t bytes, | |
2629 | int64_t *pnum, | |
2630 | int64_t *map, | |
a92b1b06 EB |
2631 | BlockDriverState **file, |
2632 | int *depth) | |
ba3f0e25 | 2633 | { |
67c095c8 | 2634 | int ret; |
ba3f0e25 | 2635 | BlockDriverState *p; |
67c095c8 | 2636 | int64_t eof = 0; |
a92b1b06 | 2637 | int dummy; |
ba3f0e25 | 2638 | |
3555a432 | 2639 | assert(!include_base || base); /* Can't include NULL base */ |
67c095c8 | 2640 | |
a92b1b06 EB |
2641 | if (!depth) { |
2642 | depth = &dummy; | |
2643 | } | |
2644 | *depth = 0; | |
2645 | ||
624f27bb VSO |
2646 | if (!include_base && bs == base) { |
2647 | *pnum = bytes; | |
2648 | return 0; | |
2649 | } | |
2650 | ||
67c095c8 | 2651 | ret = bdrv_co_block_status(bs, want_zero, offset, bytes, pnum, map, file); |
a92b1b06 | 2652 | ++*depth; |
3555a432 | 2653 | if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED || bs == base) { |
67c095c8 VSO |
2654 | return ret; |
2655 | } | |
2656 | ||
2657 | if (ret & BDRV_BLOCK_EOF) { | |
2658 | eof = offset + *pnum; | |
2659 | } | |
2660 | ||
2661 | assert(*pnum <= bytes); | |
2662 | bytes = *pnum; | |
2663 | ||
3555a432 | 2664 | for (p = bdrv_filter_or_cow_bs(bs); include_base || p != base; |
67c095c8 VSO |
2665 | p = bdrv_filter_or_cow_bs(p)) |
2666 | { | |
5b648c67 EB |
2667 | ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map, |
2668 | file); | |
a92b1b06 | 2669 | ++*depth; |
c61e684e | 2670 | if (ret < 0) { |
67c095c8 | 2671 | return ret; |
c61e684e | 2672 | } |
67c095c8 | 2673 | if (*pnum == 0) { |
c61e684e | 2674 | /* |
67c095c8 VSO |
2675 | * The top layer deferred to this layer, and because this layer is |
2676 | * short, any zeroes that we synthesize beyond EOF behave as if they | |
2677 | * were allocated at this layer. | |
2678 | * | |
2679 | * We don't include BDRV_BLOCK_EOF into ret, as upper layer may be | |
2680 | * larger. We'll add BDRV_BLOCK_EOF if needed at function end, see | |
2681 | * below. | |
c61e684e | 2682 | */ |
67c095c8 | 2683 | assert(ret & BDRV_BLOCK_EOF); |
5b648c67 | 2684 | *pnum = bytes; |
67c095c8 VSO |
2685 | if (file) { |
2686 | *file = p; | |
2687 | } | |
2688 | ret = BDRV_BLOCK_ZERO | BDRV_BLOCK_ALLOCATED; | |
2689 | break; | |
c61e684e | 2690 | } |
67c095c8 VSO |
2691 | if (ret & BDRV_BLOCK_ALLOCATED) { |
2692 | /* | |
2693 | * We've found the node and the status, we must break. | |
2694 | * | |
2695 | * Drop BDRV_BLOCK_EOF, as it's not for upper layer, which may be | |
2696 | * larger. We'll add BDRV_BLOCK_EOF if needed at function end, see | |
2697 | * below. | |
2698 | */ | |
2699 | ret &= ~BDRV_BLOCK_EOF; | |
ba3f0e25 FZ |
2700 | break; |
2701 | } | |
67c095c8 | 2702 | |
3555a432 VSO |
2703 | if (p == base) { |
2704 | assert(include_base); | |
2705 | break; | |
2706 | } | |
2707 | ||
67c095c8 VSO |
2708 | /* |
2709 | * OK, [offset, offset + *pnum) region is unallocated on this layer, | |
2710 | * let's continue the diving. | |
2711 | */ | |
2712 | assert(*pnum <= bytes); | |
2713 | bytes = *pnum; | |
ba3f0e25 | 2714 | } |
67c095c8 VSO |
2715 | |
2716 | if (offset + *pnum == eof) { | |
2717 | ret |= BDRV_BLOCK_EOF; | |
2718 | } | |
2719 | ||
ba3f0e25 FZ |
2720 | return ret; |
2721 | } | |
2722 | ||
31826642 EB |
2723 | int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, |
2724 | int64_t offset, int64_t bytes, int64_t *pnum, | |
2725 | int64_t *map, BlockDriverState **file) | |
c9ce8c4d | 2726 | { |
3555a432 | 2727 | return bdrv_common_block_status_above(bs, base, false, true, offset, bytes, |
a92b1b06 | 2728 | pnum, map, file, NULL); |
c9ce8c4d EB |
2729 | } |
2730 | ||
237d78f8 EB |
2731 | int bdrv_block_status(BlockDriverState *bs, int64_t offset, int64_t bytes, |
2732 | int64_t *pnum, int64_t *map, BlockDriverState **file) | |
ba3f0e25 | 2733 | { |
cb850315 | 2734 | return bdrv_block_status_above(bs, bdrv_filter_or_cow_bs(bs), |
31826642 | 2735 | offset, bytes, pnum, map, file); |
ba3f0e25 FZ |
2736 | } |
2737 | ||
46cd1e8a AG |
2738 | /* |
2739 | * Check @bs (and its backing chain) to see if the range defined | |
2740 | * by @offset and @bytes is known to read as zeroes. | |
2741 | * Return 1 if that is the case, 0 otherwise and -errno on error. | |
2742 | * This test is meant to be fast rather than accurate so returning 0 | |
2743 | * does not guarantee non-zero data. | |
2744 | */ | |
2745 | int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset, | |
2746 | int64_t bytes) | |
2747 | { | |
2748 | int ret; | |
2749 | int64_t pnum = bytes; | |
2750 | ||
2751 | if (!bytes) { | |
2752 | return 1; | |
2753 | } | |
2754 | ||
2755 | ret = bdrv_common_block_status_above(bs, NULL, false, false, offset, | |
a92b1b06 | 2756 | bytes, &pnum, NULL, NULL, NULL); |
46cd1e8a AG |
2757 | |
2758 | if (ret < 0) { | |
2759 | return ret; | |
2760 | } | |
2761 | ||
2762 | return (pnum == bytes) && (ret & BDRV_BLOCK_ZERO); | |
2763 | } | |
2764 | ||
d6a644bb EB |
2765 | int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset, |
2766 | int64_t bytes, int64_t *pnum) | |
61007b31 | 2767 | { |
7ddb99b9 EB |
2768 | int ret; |
2769 | int64_t dummy; | |
d6a644bb | 2770 | |
3555a432 VSO |
2771 | ret = bdrv_common_block_status_above(bs, bs, true, false, offset, |
2772 | bytes, pnum ? pnum : &dummy, NULL, | |
a92b1b06 | 2773 | NULL, NULL); |
61007b31 SH |
2774 | if (ret < 0) { |
2775 | return ret; | |
2776 | } | |
2777 | return !!(ret & BDRV_BLOCK_ALLOCATED); | |
2778 | } | |
2779 | ||
2780 | /* | |
2781 | * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] | |
2782 | * | |
a92b1b06 EB |
2783 | * Return a positive depth if (a prefix of) the given range is allocated |
2784 | * in any image between BASE and TOP (BASE is only included if include_base | |
2785 | * is set). Depth 1 is TOP, 2 is the first backing layer, and so forth. | |
170d3bd3 AS |
2786 | * BASE can be NULL to check if the given offset is allocated in any |
2787 | * image of the chain. Return 0 otherwise, or negative errno on | |
2788 | * failure. | |
61007b31 | 2789 | * |
51b0a488 EB |
2790 | * 'pnum' is set to the number of bytes (including and immediately |
2791 | * following the specified offset) that are known to be in the same | |
2792 | * allocated/unallocated state. Note that a subsequent call starting | |
2793 | * at 'offset + *pnum' may return the same allocation status (in other | |
2794 | * words, the result is not necessarily the maximum possible range); | |
2795 | * but 'pnum' will only be 0 when end of file is reached. | |
61007b31 SH |
2796 | */ |
2797 | int bdrv_is_allocated_above(BlockDriverState *top, | |
2798 | BlockDriverState *base, | |
170d3bd3 AS |
2799 | bool include_base, int64_t offset, |
2800 | int64_t bytes, int64_t *pnum) | |
61007b31 | 2801 | { |
a92b1b06 | 2802 | int depth; |
7e7e5100 | 2803 | int ret = bdrv_common_block_status_above(top, base, include_base, false, |
a92b1b06 EB |
2804 | offset, bytes, pnum, NULL, NULL, |
2805 | &depth); | |
7e7e5100 VSO |
2806 | if (ret < 0) { |
2807 | return ret; | |
61007b31 SH |
2808 | } |
2809 | ||
a92b1b06 EB |
2810 | if (ret & BDRV_BLOCK_ALLOCATED) { |
2811 | return depth; | |
2812 | } | |
2813 | return 0; | |
61007b31 SH |
2814 | } |
2815 | ||
21c2283e | 2816 | int coroutine_fn |
b33b354f | 2817 | bdrv_co_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) |
1a8ae822 KW |
2818 | { |
2819 | BlockDriver *drv = bs->drv; | |
c4db2e25 | 2820 | BlockDriverState *child_bs = bdrv_primary_bs(bs); |
b984b296 VSO |
2821 | int ret; |
2822 | ||
2823 | ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL); | |
2824 | if (ret < 0) { | |
2825 | return ret; | |
2826 | } | |
dc88a467 | 2827 | |
b33b354f VSO |
2828 | if (!drv) { |
2829 | return -ENOMEDIUM; | |
2830 | } | |
2831 | ||
dc88a467 | 2832 | bdrv_inc_in_flight(bs); |
1a8ae822 | 2833 | |
b33b354f VSO |
2834 | if (drv->bdrv_load_vmstate) { |
2835 | ret = drv->bdrv_load_vmstate(bs, qiov, pos); | |
c4db2e25 | 2836 | } else if (child_bs) { |
b33b354f | 2837 | ret = bdrv_co_readv_vmstate(child_bs, qiov, pos); |
b984b296 VSO |
2838 | } else { |
2839 | ret = -ENOTSUP; | |
1a8ae822 KW |
2840 | } |
2841 | ||
dc88a467 | 2842 | bdrv_dec_in_flight(bs); |
b33b354f | 2843 | |
dc88a467 | 2844 | return ret; |
1a8ae822 KW |
2845 | } |
2846 | ||
b33b354f VSO |
2847 | int coroutine_fn |
2848 | bdrv_co_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) | |
61007b31 | 2849 | { |
b33b354f VSO |
2850 | BlockDriver *drv = bs->drv; |
2851 | BlockDriverState *child_bs = bdrv_primary_bs(bs); | |
b984b296 VSO |
2852 | int ret; |
2853 | ||
2854 | ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL); | |
2855 | if (ret < 0) { | |
2856 | return ret; | |
2857 | } | |
61007b31 | 2858 | |
b33b354f VSO |
2859 | if (!drv) { |
2860 | return -ENOMEDIUM; | |
b433d942 KW |
2861 | } |
2862 | ||
b33b354f | 2863 | bdrv_inc_in_flight(bs); |
61007b31 | 2864 | |
b33b354f VSO |
2865 | if (drv->bdrv_save_vmstate) { |
2866 | ret = drv->bdrv_save_vmstate(bs, qiov, pos); | |
2867 | } else if (child_bs) { | |
2868 | ret = bdrv_co_writev_vmstate(child_bs, qiov, pos); | |
b984b296 VSO |
2869 | } else { |
2870 | ret = -ENOTSUP; | |
b33b354f VSO |
2871 | } |
2872 | ||
2873 | bdrv_dec_in_flight(bs); | |
2874 | ||
2875 | return ret; | |
61007b31 SH |
2876 | } |
2877 | ||
b33b354f | 2878 | int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
61007b31 | 2879 | int64_t pos, int size) |
5ddda0b8 | 2880 | { |
0d93ed08 | 2881 | QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, size); |
b33b354f | 2882 | int ret = bdrv_writev_vmstate(bs, &qiov, pos); |
b433d942 | 2883 | |
b33b354f | 2884 | return ret < 0 ? ret : size; |
5ddda0b8 KW |
2885 | } |
2886 | ||
b33b354f VSO |
2887 | int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
2888 | int64_t pos, int size) | |
61007b31 | 2889 | { |
b33b354f VSO |
2890 | QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, size); |
2891 | int ret = bdrv_readv_vmstate(bs, &qiov, pos); | |
2892 | ||
2893 | return ret < 0 ? ret : size; | |
61007b31 SH |
2894 | } |
2895 | ||
2896 | /**************************************************************/ | |
2897 | /* async I/Os */ | |
2898 | ||
61007b31 SH |
2899 | void bdrv_aio_cancel(BlockAIOCB *acb) |
2900 | { | |
2901 | qemu_aio_ref(acb); | |
2902 | bdrv_aio_cancel_async(acb); | |
2903 | while (acb->refcnt > 1) { | |
2904 | if (acb->aiocb_info->get_aio_context) { | |
2905 | aio_poll(acb->aiocb_info->get_aio_context(acb), true); | |
2906 | } else if (acb->bs) { | |
2f47da5f PB |
2907 | /* qemu_aio_ref and qemu_aio_unref are not thread-safe, so |
2908 | * assert that we're not using an I/O thread. Thread-safe | |
2909 | * code should use bdrv_aio_cancel_async exclusively. | |
2910 | */ | |
2911 | assert(bdrv_get_aio_context(acb->bs) == qemu_get_aio_context()); | |
61007b31 SH |
2912 | aio_poll(bdrv_get_aio_context(acb->bs), true); |
2913 | } else { | |
2914 | abort(); | |
2915 | } | |
2916 | } | |
2917 | qemu_aio_unref(acb); | |
2918 | } | |
2919 | ||
2920 | /* Async version of aio cancel. The caller is not blocked if the acb implements | |
2921 | * cancel_async, otherwise we do nothing and let the request normally complete. | |
2922 | * In either case the completion callback must be called. */ | |
2923 | void bdrv_aio_cancel_async(BlockAIOCB *acb) | |
2924 | { | |
2925 | if (acb->aiocb_info->cancel_async) { | |
2926 | acb->aiocb_info->cancel_async(acb); | |
2927 | } | |
2928 | } | |
2929 | ||
61007b31 SH |
2930 | /**************************************************************/ |
2931 | /* Coroutine block device emulation */ | |
2932 | ||
61007b31 SH |
2933 | int coroutine_fn bdrv_co_flush(BlockDriverState *bs) |
2934 | { | |
883833e2 HR |
2935 | BdrvChild *primary_child = bdrv_primary_child(bs); |
2936 | BdrvChild *child; | |
49ca6259 FZ |
2937 | int current_gen; |
2938 | int ret = 0; | |
2939 | ||
2940 | bdrv_inc_in_flight(bs); | |
61007b31 | 2941 | |
e914404e | 2942 | if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || |
1b6bc94d | 2943 | bdrv_is_sg(bs)) { |
49ca6259 | 2944 | goto early_exit; |
61007b31 SH |
2945 | } |
2946 | ||
3783fa3d | 2947 | qemu_co_mutex_lock(&bs->reqs_lock); |
d73415a3 | 2948 | current_gen = qatomic_read(&bs->write_gen); |
3ff2f67a EY |
2949 | |
2950 | /* Wait until any previous flushes are completed */ | |
99723548 | 2951 | while (bs->active_flush_req) { |
3783fa3d | 2952 | qemu_co_queue_wait(&bs->flush_queue, &bs->reqs_lock); |
3ff2f67a EY |
2953 | } |
2954 | ||
3783fa3d | 2955 | /* Flushes reach this point in nondecreasing current_gen order. */ |
99723548 | 2956 | bs->active_flush_req = true; |
3783fa3d | 2957 | qemu_co_mutex_unlock(&bs->reqs_lock); |
3ff2f67a | 2958 | |
c32b82af PD |
2959 | /* Write back all layers by calling one driver function */ |
2960 | if (bs->drv->bdrv_co_flush) { | |
2961 | ret = bs->drv->bdrv_co_flush(bs); | |
2962 | goto out; | |
2963 | } | |
2964 | ||
61007b31 | 2965 | /* Write back cached data to the OS even with cache=unsafe */ |
883833e2 | 2966 | BLKDBG_EVENT(primary_child, BLKDBG_FLUSH_TO_OS); |
61007b31 SH |
2967 | if (bs->drv->bdrv_co_flush_to_os) { |
2968 | ret = bs->drv->bdrv_co_flush_to_os(bs); | |
2969 | if (ret < 0) { | |
cdb5e315 | 2970 | goto out; |
61007b31 SH |
2971 | } |
2972 | } | |
2973 | ||
2974 | /* But don't actually force it to the disk with cache=unsafe */ | |
2975 | if (bs->open_flags & BDRV_O_NO_FLUSH) { | |
883833e2 | 2976 | goto flush_children; |
61007b31 SH |
2977 | } |
2978 | ||
3ff2f67a EY |
2979 | /* Check if we really need to flush anything */ |
2980 | if (bs->flushed_gen == current_gen) { | |
883833e2 | 2981 | goto flush_children; |
3ff2f67a EY |
2982 | } |
2983 | ||
883833e2 | 2984 | BLKDBG_EVENT(primary_child, BLKDBG_FLUSH_TO_DISK); |
d470ad42 HR |
2985 | if (!bs->drv) { |
2986 | /* bs->drv->bdrv_co_flush() might have ejected the BDS | |
2987 | * (even in case of apparent success) */ | |
2988 | ret = -ENOMEDIUM; | |
2989 | goto out; | |
2990 | } | |
61007b31 SH |
2991 | if (bs->drv->bdrv_co_flush_to_disk) { |
2992 | ret = bs->drv->bdrv_co_flush_to_disk(bs); | |
2993 | } else if (bs->drv->bdrv_aio_flush) { | |
2994 | BlockAIOCB *acb; | |
2995 | CoroutineIOCompletion co = { | |
2996 | .coroutine = qemu_coroutine_self(), | |
2997 | }; | |
2998 | ||
2999 | acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); | |
3000 | if (acb == NULL) { | |
3001 | ret = -EIO; | |
3002 | } else { | |
3003 | qemu_coroutine_yield(); | |
3004 | ret = co.ret; | |
3005 | } | |
3006 | } else { | |
3007 | /* | |
3008 | * Some block drivers always operate in either writethrough or unsafe | |
3009 | * mode and don't support bdrv_flush therefore. Usually qemu doesn't | |
3010 | * know how the server works (because the behaviour is hardcoded or | |
3011 | * depends on server-side configuration), so we can't ensure that | |
3012 | * everything is safe on disk. Returning an error doesn't work because | |
3013 | * that would break guests even if the server operates in writethrough | |
3014 | * mode. | |
3015 | * | |
3016 | * Let's hope the user knows what he's doing. | |
3017 | */ | |
3018 | ret = 0; | |
3019 | } | |
3ff2f67a | 3020 | |
61007b31 | 3021 | if (ret < 0) { |
cdb5e315 | 3022 | goto out; |
61007b31 SH |
3023 | } |
3024 | ||
3025 | /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH | |
3026 | * in the case of cache=unsafe, so there are no useless flushes. | |
3027 | */ | |
883833e2 HR |
3028 | flush_children: |
3029 | ret = 0; | |
3030 | QLIST_FOREACH(child, &bs->children, next) { | |
3031 | if (child->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) { | |
3032 | int this_child_ret = bdrv_co_flush(child->bs); | |
3033 | if (!ret) { | |
3034 | ret = this_child_ret; | |
3035 | } | |
3036 | } | |
3037 | } | |
3038 | ||
cdb5e315 | 3039 | out: |
3ff2f67a | 3040 | /* Notify any pending flushes that we have completed */ |
e6af1e08 KW |
3041 | if (ret == 0) { |
3042 | bs->flushed_gen = current_gen; | |
3043 | } | |
3783fa3d PB |
3044 | |
3045 | qemu_co_mutex_lock(&bs->reqs_lock); | |
99723548 | 3046 | bs->active_flush_req = false; |
156af3ac DL |
3047 | /* Return value is ignored - it's ok if wait queue is empty */ |
3048 | qemu_co_queue_next(&bs->flush_queue); | |
3783fa3d | 3049 | qemu_co_mutex_unlock(&bs->reqs_lock); |
3ff2f67a | 3050 | |
49ca6259 | 3051 | early_exit: |
99723548 | 3052 | bdrv_dec_in_flight(bs); |
cdb5e315 | 3053 | return ret; |
61007b31 SH |
3054 | } |
3055 | ||
d93e5726 VSO |
3056 | int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset, |
3057 | int64_t bytes) | |
61007b31 | 3058 | { |
b1066c87 | 3059 | BdrvTrackedRequest req; |
39af49c0 VSO |
3060 | int ret; |
3061 | int64_t max_pdiscard; | |
3482b9bc | 3062 | int head, tail, align; |
0b9fd3f4 | 3063 | BlockDriverState *bs = child->bs; |
61007b31 | 3064 | |
d93e5726 | 3065 | if (!bs || !bs->drv || !bdrv_is_inserted(bs)) { |
61007b31 SH |
3066 | return -ENOMEDIUM; |
3067 | } | |
3068 | ||
d6883bc9 VSO |
3069 | if (bdrv_has_readonly_bitmaps(bs)) { |
3070 | return -EPERM; | |
3071 | } | |
3072 | ||
69b55e03 | 3073 | ret = bdrv_check_request(offset, bytes, NULL); |
8b117001 VSO |
3074 | if (ret < 0) { |
3075 | return ret; | |
61007b31 SH |
3076 | } |
3077 | ||
61007b31 SH |
3078 | /* Do nothing if disabled. */ |
3079 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
3080 | return 0; | |
3081 | } | |
3082 | ||
02aefe43 | 3083 | if (!bs->drv->bdrv_co_pdiscard && !bs->drv->bdrv_aio_pdiscard) { |
61007b31 SH |
3084 | return 0; |
3085 | } | |
3086 | ||
0bc329fb HR |
3087 | /* Invalidate the cached block-status data range if this discard overlaps */ |
3088 | bdrv_bsc_invalidate_range(bs, offset, bytes); | |
3089 | ||
3482b9bc EB |
3090 | /* Discard is advisory, but some devices track and coalesce |
3091 | * unaligned requests, so we must pass everything down rather than | |
3092 | * round here. Still, most devices will just silently ignore | |
3093 | * unaligned requests (by returning -ENOTSUP), so we must fragment | |
3094 | * the request accordingly. */ | |
02aefe43 | 3095 | align = MAX(bs->bl.pdiscard_alignment, bs->bl.request_alignment); |
b8d0a980 EB |
3096 | assert(align % bs->bl.request_alignment == 0); |
3097 | head = offset % align; | |
f5a5ca79 | 3098 | tail = (offset + bytes) % align; |
9f1963b3 | 3099 | |
99723548 | 3100 | bdrv_inc_in_flight(bs); |
f5a5ca79 | 3101 | tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_DISCARD); |
50824995 | 3102 | |
00695c27 | 3103 | ret = bdrv_co_write_req_prepare(child, offset, bytes, &req, 0); |
ec050f77 DL |
3104 | if (ret < 0) { |
3105 | goto out; | |
3106 | } | |
3107 | ||
6a8f3dbb | 3108 | max_pdiscard = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_pdiscard, INT64_MAX), |
9f1963b3 | 3109 | align); |
3482b9bc | 3110 | assert(max_pdiscard >= bs->bl.request_alignment); |
61007b31 | 3111 | |
f5a5ca79 | 3112 | while (bytes > 0) { |
d93e5726 | 3113 | int64_t num = bytes; |
3482b9bc EB |
3114 | |
3115 | if (head) { | |
3116 | /* Make small requests to get to alignment boundaries. */ | |
f5a5ca79 | 3117 | num = MIN(bytes, align - head); |
3482b9bc EB |
3118 | if (!QEMU_IS_ALIGNED(num, bs->bl.request_alignment)) { |
3119 | num %= bs->bl.request_alignment; | |
3120 | } | |
3121 | head = (head + num) % align; | |
3122 | assert(num < max_pdiscard); | |
3123 | } else if (tail) { | |
3124 | if (num > align) { | |
3125 | /* Shorten the request to the last aligned cluster. */ | |
3126 | num -= tail; | |
3127 | } else if (!QEMU_IS_ALIGNED(tail, bs->bl.request_alignment) && | |
3128 | tail > bs->bl.request_alignment) { | |
3129 | tail %= bs->bl.request_alignment; | |
3130 | num -= tail; | |
3131 | } | |
3132 | } | |
3133 | /* limit request size */ | |
3134 | if (num > max_pdiscard) { | |
3135 | num = max_pdiscard; | |
3136 | } | |
61007b31 | 3137 | |
d470ad42 HR |
3138 | if (!bs->drv) { |
3139 | ret = -ENOMEDIUM; | |
3140 | goto out; | |
3141 | } | |
47a5486d EB |
3142 | if (bs->drv->bdrv_co_pdiscard) { |
3143 | ret = bs->drv->bdrv_co_pdiscard(bs, offset, num); | |
61007b31 SH |
3144 | } else { |
3145 | BlockAIOCB *acb; | |
3146 | CoroutineIOCompletion co = { | |
3147 | .coroutine = qemu_coroutine_self(), | |
3148 | }; | |
3149 | ||
4da444a0 EB |
3150 | acb = bs->drv->bdrv_aio_pdiscard(bs, offset, num, |
3151 | bdrv_co_io_em_complete, &co); | |
61007b31 | 3152 | if (acb == NULL) { |
b1066c87 FZ |
3153 | ret = -EIO; |
3154 | goto out; | |
61007b31 SH |
3155 | } else { |
3156 | qemu_coroutine_yield(); | |
3157 | ret = co.ret; | |
3158 | } | |
3159 | } | |
3160 | if (ret && ret != -ENOTSUP) { | |
b1066c87 | 3161 | goto out; |
61007b31 SH |
3162 | } |
3163 | ||
9f1963b3 | 3164 | offset += num; |
f5a5ca79 | 3165 | bytes -= num; |
61007b31 | 3166 | } |
b1066c87 FZ |
3167 | ret = 0; |
3168 | out: | |
00695c27 | 3169 | bdrv_co_write_req_finish(child, req.offset, req.bytes, &req, ret); |
b1066c87 | 3170 | tracked_request_end(&req); |
99723548 | 3171 | bdrv_dec_in_flight(bs); |
b1066c87 | 3172 | return ret; |
61007b31 SH |
3173 | } |
3174 | ||
48af776a | 3175 | int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf) |
61007b31 SH |
3176 | { |
3177 | BlockDriver *drv = bs->drv; | |
5c5ae76a FZ |
3178 | CoroutineIOCompletion co = { |
3179 | .coroutine = qemu_coroutine_self(), | |
3180 | }; | |
3181 | BlockAIOCB *acb; | |
61007b31 | 3182 | |
99723548 | 3183 | bdrv_inc_in_flight(bs); |
16a389dc | 3184 | if (!drv || (!drv->bdrv_aio_ioctl && !drv->bdrv_co_ioctl)) { |
5c5ae76a FZ |
3185 | co.ret = -ENOTSUP; |
3186 | goto out; | |
3187 | } | |
3188 | ||
16a389dc KW |
3189 | if (drv->bdrv_co_ioctl) { |
3190 | co.ret = drv->bdrv_co_ioctl(bs, req, buf); | |
3191 | } else { | |
3192 | acb = drv->bdrv_aio_ioctl(bs, req, buf, bdrv_co_io_em_complete, &co); | |
3193 | if (!acb) { | |
3194 | co.ret = -ENOTSUP; | |
3195 | goto out; | |
3196 | } | |
3197 | qemu_coroutine_yield(); | |
5c5ae76a | 3198 | } |
5c5ae76a | 3199 | out: |
99723548 | 3200 | bdrv_dec_in_flight(bs); |
5c5ae76a FZ |
3201 | return co.ret; |
3202 | } | |
3203 | ||
61007b31 SH |
3204 | void *qemu_blockalign(BlockDriverState *bs, size_t size) |
3205 | { | |
3206 | return qemu_memalign(bdrv_opt_mem_align(bs), size); | |
3207 | } | |
3208 | ||
3209 | void *qemu_blockalign0(BlockDriverState *bs, size_t size) | |
3210 | { | |
3211 | return memset(qemu_blockalign(bs, size), 0, size); | |
3212 | } | |
3213 | ||
3214 | void *qemu_try_blockalign(BlockDriverState *bs, size_t size) | |
3215 | { | |
3216 | size_t align = bdrv_opt_mem_align(bs); | |
3217 | ||
3218 | /* Ensure that NULL is never returned on success */ | |
3219 | assert(align > 0); | |
3220 | if (size == 0) { | |
3221 | size = align; | |
3222 | } | |
3223 | ||
3224 | return qemu_try_memalign(align, size); | |
3225 | } | |
3226 | ||
3227 | void *qemu_try_blockalign0(BlockDriverState *bs, size_t size) | |
3228 | { | |
3229 | void *mem = qemu_try_blockalign(bs, size); | |
3230 | ||
3231 | if (mem) { | |
3232 | memset(mem, 0, size); | |
3233 | } | |
3234 | ||
3235 | return mem; | |
3236 | } | |
3237 | ||
3238 | /* | |
3239 | * Check if all memory in this vector is sector aligned. | |
3240 | */ | |
3241 | bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) | |
3242 | { | |
3243 | int i; | |
4196d2f0 | 3244 | size_t alignment = bdrv_min_mem_align(bs); |
61007b31 SH |
3245 | |
3246 | for (i = 0; i < qiov->niov; i++) { | |
3247 | if ((uintptr_t) qiov->iov[i].iov_base % alignment) { | |
3248 | return false; | |
3249 | } | |
3250 | if (qiov->iov[i].iov_len % alignment) { | |
3251 | return false; | |
3252 | } | |
3253 | } | |
3254 | ||
3255 | return true; | |
3256 | } | |
3257 | ||
61007b31 SH |
3258 | void bdrv_io_plug(BlockDriverState *bs) |
3259 | { | |
6b98bd64 PB |
3260 | BdrvChild *child; |
3261 | ||
3262 | QLIST_FOREACH(child, &bs->children, next) { | |
3263 | bdrv_io_plug(child->bs); | |
3264 | } | |
3265 | ||
d73415a3 | 3266 | if (qatomic_fetch_inc(&bs->io_plugged) == 0) { |
6b98bd64 PB |
3267 | BlockDriver *drv = bs->drv; |
3268 | if (drv && drv->bdrv_io_plug) { | |
3269 | drv->bdrv_io_plug(bs); | |
3270 | } | |
61007b31 SH |
3271 | } |
3272 | } | |
3273 | ||
3274 | void bdrv_io_unplug(BlockDriverState *bs) | |
3275 | { | |
6b98bd64 PB |
3276 | BdrvChild *child; |
3277 | ||
3278 | assert(bs->io_plugged); | |
d73415a3 | 3279 | if (qatomic_fetch_dec(&bs->io_plugged) == 1) { |
6b98bd64 PB |
3280 | BlockDriver *drv = bs->drv; |
3281 | if (drv && drv->bdrv_io_unplug) { | |
3282 | drv->bdrv_io_unplug(bs); | |
3283 | } | |
3284 | } | |
3285 | ||
3286 | QLIST_FOREACH(child, &bs->children, next) { | |
3287 | bdrv_io_unplug(child->bs); | |
61007b31 SH |
3288 | } |
3289 | } | |
23d0ba93 FZ |
3290 | |
3291 | void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size) | |
3292 | { | |
3293 | BdrvChild *child; | |
3294 | ||
3295 | if (bs->drv && bs->drv->bdrv_register_buf) { | |
3296 | bs->drv->bdrv_register_buf(bs, host, size); | |
3297 | } | |
3298 | QLIST_FOREACH(child, &bs->children, next) { | |
3299 | bdrv_register_buf(child->bs, host, size); | |
3300 | } | |
3301 | } | |
3302 | ||
3303 | void bdrv_unregister_buf(BlockDriverState *bs, void *host) | |
3304 | { | |
3305 | BdrvChild *child; | |
3306 | ||
3307 | if (bs->drv && bs->drv->bdrv_unregister_buf) { | |
3308 | bs->drv->bdrv_unregister_buf(bs, host); | |
3309 | } | |
3310 | QLIST_FOREACH(child, &bs->children, next) { | |
3311 | bdrv_unregister_buf(child->bs, host); | |
3312 | } | |
3313 | } | |
fcc67678 | 3314 | |
67b51fb9 | 3315 | static int coroutine_fn bdrv_co_copy_range_internal( |
a5215b8f VSO |
3316 | BdrvChild *src, int64_t src_offset, BdrvChild *dst, |
3317 | int64_t dst_offset, int64_t bytes, | |
67b51fb9 VSO |
3318 | BdrvRequestFlags read_flags, BdrvRequestFlags write_flags, |
3319 | bool recurse_src) | |
fcc67678 | 3320 | { |
999658a0 | 3321 | BdrvTrackedRequest req; |
fcc67678 FZ |
3322 | int ret; |
3323 | ||
fe0480d6 KW |
3324 | /* TODO We can support BDRV_REQ_NO_FALLBACK here */ |
3325 | assert(!(read_flags & BDRV_REQ_NO_FALLBACK)); | |
3326 | assert(!(write_flags & BDRV_REQ_NO_FALLBACK)); | |
3327 | ||
f4dad307 | 3328 | if (!dst || !dst->bs || !bdrv_is_inserted(dst->bs)) { |
fcc67678 FZ |
3329 | return -ENOMEDIUM; |
3330 | } | |
63f4ad11 | 3331 | ret = bdrv_check_request32(dst_offset, bytes, NULL, 0); |
fcc67678 FZ |
3332 | if (ret) { |
3333 | return ret; | |
3334 | } | |
67b51fb9 VSO |
3335 | if (write_flags & BDRV_REQ_ZERO_WRITE) { |
3336 | return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, write_flags); | |
fcc67678 FZ |
3337 | } |
3338 | ||
f4dad307 | 3339 | if (!src || !src->bs || !bdrv_is_inserted(src->bs)) { |
d4d3e5a0 FZ |
3340 | return -ENOMEDIUM; |
3341 | } | |
63f4ad11 | 3342 | ret = bdrv_check_request32(src_offset, bytes, NULL, 0); |
d4d3e5a0 FZ |
3343 | if (ret) { |
3344 | return ret; | |
3345 | } | |
3346 | ||
fcc67678 FZ |
3347 | if (!src->bs->drv->bdrv_co_copy_range_from |
3348 | || !dst->bs->drv->bdrv_co_copy_range_to | |
3349 | || src->bs->encrypted || dst->bs->encrypted) { | |
3350 | return -ENOTSUP; | |
3351 | } | |
37aec7d7 | 3352 | |
fcc67678 | 3353 | if (recurse_src) { |
999658a0 VSO |
3354 | bdrv_inc_in_flight(src->bs); |
3355 | tracked_request_begin(&req, src->bs, src_offset, bytes, | |
3356 | BDRV_TRACKED_READ); | |
3357 | ||
09d2f948 VSO |
3358 | /* BDRV_REQ_SERIALISING is only for write operation */ |
3359 | assert(!(read_flags & BDRV_REQ_SERIALISING)); | |
c53cb427 | 3360 | bdrv_wait_serialising_requests(&req); |
999658a0 | 3361 | |
37aec7d7 FZ |
3362 | ret = src->bs->drv->bdrv_co_copy_range_from(src->bs, |
3363 | src, src_offset, | |
3364 | dst, dst_offset, | |
67b51fb9 VSO |
3365 | bytes, |
3366 | read_flags, write_flags); | |
999658a0 VSO |
3367 | |
3368 | tracked_request_end(&req); | |
3369 | bdrv_dec_in_flight(src->bs); | |
fcc67678 | 3370 | } else { |
999658a0 VSO |
3371 | bdrv_inc_in_flight(dst->bs); |
3372 | tracked_request_begin(&req, dst->bs, dst_offset, bytes, | |
3373 | BDRV_TRACKED_WRITE); | |
0eb1e891 FZ |
3374 | ret = bdrv_co_write_req_prepare(dst, dst_offset, bytes, &req, |
3375 | write_flags); | |
3376 | if (!ret) { | |
3377 | ret = dst->bs->drv->bdrv_co_copy_range_to(dst->bs, | |
3378 | src, src_offset, | |
3379 | dst, dst_offset, | |
3380 | bytes, | |
3381 | read_flags, write_flags); | |
3382 | } | |
3383 | bdrv_co_write_req_finish(dst, dst_offset, bytes, &req, ret); | |
999658a0 VSO |
3384 | tracked_request_end(&req); |
3385 | bdrv_dec_in_flight(dst->bs); | |
fcc67678 | 3386 | } |
999658a0 | 3387 | |
37aec7d7 | 3388 | return ret; |
fcc67678 FZ |
3389 | } |
3390 | ||
3391 | /* Copy range from @src to @dst. | |
3392 | * | |
3393 | * See the comment of bdrv_co_copy_range for the parameter and return value | |
3394 | * semantics. */ | |
a5215b8f VSO |
3395 | int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, int64_t src_offset, |
3396 | BdrvChild *dst, int64_t dst_offset, | |
3397 | int64_t bytes, | |
67b51fb9 VSO |
3398 | BdrvRequestFlags read_flags, |
3399 | BdrvRequestFlags write_flags) | |
fcc67678 | 3400 | { |
ecc983a5 FZ |
3401 | trace_bdrv_co_copy_range_from(src, src_offset, dst, dst_offset, bytes, |
3402 | read_flags, write_flags); | |
fcc67678 | 3403 | return bdrv_co_copy_range_internal(src, src_offset, dst, dst_offset, |
67b51fb9 | 3404 | bytes, read_flags, write_flags, true); |
fcc67678 FZ |
3405 | } |
3406 | ||
3407 | /* Copy range from @src to @dst. | |
3408 | * | |
3409 | * See the comment of bdrv_co_copy_range for the parameter and return value | |
3410 | * semantics. */ | |
a5215b8f VSO |
3411 | int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, int64_t src_offset, |
3412 | BdrvChild *dst, int64_t dst_offset, | |
3413 | int64_t bytes, | |
67b51fb9 VSO |
3414 | BdrvRequestFlags read_flags, |
3415 | BdrvRequestFlags write_flags) | |
fcc67678 | 3416 | { |
ecc983a5 FZ |
3417 | trace_bdrv_co_copy_range_to(src, src_offset, dst, dst_offset, bytes, |
3418 | read_flags, write_flags); | |
fcc67678 | 3419 | return bdrv_co_copy_range_internal(src, src_offset, dst, dst_offset, |
67b51fb9 | 3420 | bytes, read_flags, write_flags, false); |
fcc67678 FZ |
3421 | } |
3422 | ||
a5215b8f VSO |
3423 | int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset, |
3424 | BdrvChild *dst, int64_t dst_offset, | |
3425 | int64_t bytes, BdrvRequestFlags read_flags, | |
67b51fb9 | 3426 | BdrvRequestFlags write_flags) |
fcc67678 | 3427 | { |
37aec7d7 FZ |
3428 | return bdrv_co_copy_range_from(src, src_offset, |
3429 | dst, dst_offset, | |
67b51fb9 | 3430 | bytes, read_flags, write_flags); |
fcc67678 | 3431 | } |
3d9f2d2a KW |
3432 | |
3433 | static void bdrv_parent_cb_resize(BlockDriverState *bs) | |
3434 | { | |
3435 | BdrvChild *c; | |
3436 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
bd86fb99 HR |
3437 | if (c->klass->resize) { |
3438 | c->klass->resize(c); | |
3d9f2d2a KW |
3439 | } |
3440 | } | |
3441 | } | |
3442 | ||
3443 | /** | |
3444 | * Truncate file to 'offset' bytes (needed only for file protocols) | |
c80d8b06 HR |
3445 | * |
3446 | * If 'exact' is true, the file must be resized to exactly the given | |
3447 | * 'offset'. Otherwise, it is sufficient for the node to be at least | |
3448 | * 'offset' bytes in length. | |
3d9f2d2a | 3449 | */ |
c80d8b06 | 3450 | int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact, |
7b8e4857 KW |
3451 | PreallocMode prealloc, BdrvRequestFlags flags, |
3452 | Error **errp) | |
3d9f2d2a KW |
3453 | { |
3454 | BlockDriverState *bs = child->bs; | |
23b93525 | 3455 | BdrvChild *filtered, *backing; |
3d9f2d2a | 3456 | BlockDriver *drv = bs->drv; |
1bc5f09f KW |
3457 | BdrvTrackedRequest req; |
3458 | int64_t old_size, new_bytes; | |
3d9f2d2a KW |
3459 | int ret; |
3460 | ||
3d9f2d2a KW |
3461 | |
3462 | /* if bs->drv == NULL, bs is closed, so there's nothing to do here */ | |
3463 | if (!drv) { | |
3464 | error_setg(errp, "No medium inserted"); | |
3465 | return -ENOMEDIUM; | |
3466 | } | |
3467 | if (offset < 0) { | |
3468 | error_setg(errp, "Image size cannot be negative"); | |
3469 | return -EINVAL; | |
3470 | } | |
3471 | ||
69b55e03 | 3472 | ret = bdrv_check_request(offset, 0, errp); |
8b117001 | 3473 | if (ret < 0) { |
8b117001 VSO |
3474 | return ret; |
3475 | } | |
3476 | ||
1bc5f09f KW |
3477 | old_size = bdrv_getlength(bs); |
3478 | if (old_size < 0) { | |
3479 | error_setg_errno(errp, -old_size, "Failed to get old image size"); | |
3480 | return old_size; | |
3481 | } | |
3482 | ||
97efa869 EB |
3483 | if (bdrv_is_read_only(bs)) { |
3484 | error_setg(errp, "Image is read-only"); | |
3485 | return -EACCES; | |
3486 | } | |
3487 | ||
1bc5f09f KW |
3488 | if (offset > old_size) { |
3489 | new_bytes = offset - old_size; | |
3490 | } else { | |
3491 | new_bytes = 0; | |
3492 | } | |
3493 | ||
3d9f2d2a | 3494 | bdrv_inc_in_flight(bs); |
5416a11e FZ |
3495 | tracked_request_begin(&req, bs, offset - new_bytes, new_bytes, |
3496 | BDRV_TRACKED_TRUNCATE); | |
1bc5f09f KW |
3497 | |
3498 | /* If we are growing the image and potentially using preallocation for the | |
3499 | * new area, we need to make sure that no write requests are made to it | |
3500 | * concurrently or they might be overwritten by preallocation. */ | |
3501 | if (new_bytes) { | |
8ac5aab2 | 3502 | bdrv_make_request_serialising(&req, 1); |
cd47d792 | 3503 | } |
cd47d792 FZ |
3504 | ret = bdrv_co_write_req_prepare(child, offset - new_bytes, new_bytes, &req, |
3505 | 0); | |
3506 | if (ret < 0) { | |
3507 | error_setg_errno(errp, -ret, | |
3508 | "Failed to prepare request for truncation"); | |
3509 | goto out; | |
1bc5f09f | 3510 | } |
3d9f2d2a | 3511 | |
93393e69 | 3512 | filtered = bdrv_filter_child(bs); |
23b93525 | 3513 | backing = bdrv_cow_child(bs); |
93393e69 | 3514 | |
955c7d66 KW |
3515 | /* |
3516 | * If the image has a backing file that is large enough that it would | |
3517 | * provide data for the new area, we cannot leave it unallocated because | |
3518 | * then the backing file content would become visible. Instead, zero-fill | |
3519 | * the new area. | |
3520 | * | |
3521 | * Note that if the image has a backing file, but was opened without the | |
3522 | * backing file, taking care of keeping things consistent with that backing | |
3523 | * file is the user's responsibility. | |
3524 | */ | |
23b93525 | 3525 | if (new_bytes && backing) { |
955c7d66 KW |
3526 | int64_t backing_len; |
3527 | ||
23b93525 | 3528 | backing_len = bdrv_getlength(backing->bs); |
955c7d66 KW |
3529 | if (backing_len < 0) { |
3530 | ret = backing_len; | |
3531 | error_setg_errno(errp, -ret, "Could not get backing file size"); | |
3532 | goto out; | |
3533 | } | |
3534 | ||
3535 | if (backing_len > old_size) { | |
3536 | flags |= BDRV_REQ_ZERO_WRITE; | |
3537 | } | |
3538 | } | |
3539 | ||
6b7e8f8b | 3540 | if (drv->bdrv_co_truncate) { |
92b92799 KW |
3541 | if (flags & ~bs->supported_truncate_flags) { |
3542 | error_setg(errp, "Block driver does not support requested flags"); | |
3543 | ret = -ENOTSUP; | |
3544 | goto out; | |
3545 | } | |
3546 | ret = drv->bdrv_co_truncate(bs, offset, exact, prealloc, flags, errp); | |
93393e69 HR |
3547 | } else if (filtered) { |
3548 | ret = bdrv_co_truncate(filtered, offset, exact, prealloc, flags, errp); | |
6b7e8f8b | 3549 | } else { |
3d9f2d2a KW |
3550 | error_setg(errp, "Image format driver does not support resize"); |
3551 | ret = -ENOTSUP; | |
3552 | goto out; | |
3553 | } | |
3d9f2d2a KW |
3554 | if (ret < 0) { |
3555 | goto out; | |
3556 | } | |
6b7e8f8b | 3557 | |
3d9f2d2a KW |
3558 | ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); |
3559 | if (ret < 0) { | |
3560 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
3561 | } else { | |
3562 | offset = bs->total_sectors * BDRV_SECTOR_SIZE; | |
3563 | } | |
cd47d792 FZ |
3564 | /* It's possible that truncation succeeded but refresh_total_sectors |
3565 | * failed, but the latter doesn't affect how we should finish the request. | |
3566 | * Pass 0 as the last parameter so that dirty bitmaps etc. are handled. */ | |
3567 | bdrv_co_write_req_finish(child, offset - new_bytes, new_bytes, &req, 0); | |
3d9f2d2a KW |
3568 | |
3569 | out: | |
1bc5f09f | 3570 | tracked_request_end(&req); |
3d9f2d2a | 3571 | bdrv_dec_in_flight(bs); |
1bc5f09f | 3572 | |
3d9f2d2a KW |
3573 | return ret; |
3574 | } | |
bd54669a VSO |
3575 | |
3576 | void bdrv_cancel_in_flight(BlockDriverState *bs) | |
3577 | { | |
3578 | if (!bs || !bs->drv) { | |
3579 | return; | |
3580 | } | |
3581 | ||
3582 | if (bs->drv->bdrv_cancel_in_flight) { | |
3583 | bs->drv->bdrv_cancel_in_flight(bs); | |
3584 | } | |
3585 | } |