1 /* 2 * Block node draining tests 3 * 4 * Copyright (c) 2017 Kevin Wolf <kwolf@redhat.com> 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #include "qemu/osdep.h" 26 #include "block/block_int.h" 27 #include "block/blockjob_int.h" 28 #include "sysemu/block-backend.h" 29 #include "qapi/error.h" 30 #include "qemu/main-loop.h" 31 #include "iothread.h" 32 33 static QemuEvent done_event; 34 35 typedef struct BDRVTestState { 36 int drain_count; 37 AioContext *bh_indirection_ctx; 38 bool sleep_in_drain_begin; 39 } BDRVTestState; 40 41 static void coroutine_fn sleep_in_drain_begin(void *opaque) 42 { 43 BlockDriverState *bs = opaque; 44 45 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000); 46 bdrv_dec_in_flight(bs); 47 } 48 49 static void bdrv_test_drain_begin(BlockDriverState *bs) 50 { 51 BDRVTestState *s = bs->opaque; 52 s->drain_count++; 53 if (s->sleep_in_drain_begin) { 54 Coroutine *co = qemu_coroutine_create(sleep_in_drain_begin, bs); 55 bdrv_inc_in_flight(bs); 56 aio_co_enter(bdrv_get_aio_context(bs), co); 57 } 58 } 59 60 static void bdrv_test_drain_end(BlockDriverState *bs) 61 { 62 BDRVTestState *s = bs->opaque; 63 s->drain_count--; 64 } 65 66 static void bdrv_test_close(BlockDriverState *bs) 67 { 68 BDRVTestState *s = bs->opaque; 69 g_assert_cmpint(s->drain_count, >, 0); 70 } 71 72 static void co_reenter_bh(void *opaque) 73 { 74 aio_co_wake(opaque); 75 } 76 77 static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs, 78 int64_t offset, int64_t bytes, 79 QEMUIOVector *qiov, 80 BdrvRequestFlags flags) 81 { 82 BDRVTestState *s = bs->opaque; 83 84 /* We want this request to stay until the polling loop in drain waits for 85 * it to complete. We need to sleep a while as bdrv_drain_invoke() comes 86 * first and polls its result, too, but it shouldn't accidentally complete 87 * this request yet. */ 88 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000); 89 90 if (s->bh_indirection_ctx) { 91 aio_bh_schedule_oneshot(s->bh_indirection_ctx, co_reenter_bh, 92 qemu_coroutine_self()); 93 qemu_coroutine_yield(); 94 } 95 96 return 0; 97 } 98 99 static int bdrv_test_change_backing_file(BlockDriverState *bs, 100 const char *backing_file, 101 const char *backing_fmt) 102 { 103 return 0; 104 } 105 106 static BlockDriver bdrv_test = { 107 .format_name = "test", 108 .instance_size = sizeof(BDRVTestState), 109 .supports_backing = true, 110 111 .bdrv_close = bdrv_test_close, 112 .bdrv_co_preadv = bdrv_test_co_preadv, 113 114 .bdrv_drain_begin = bdrv_test_drain_begin, 115 .bdrv_drain_end = bdrv_test_drain_end, 116 117 .bdrv_child_perm = bdrv_default_perms, 118 119 .bdrv_change_backing_file = bdrv_test_change_backing_file, 120 }; 121 122 static void aio_ret_cb(void *opaque, int ret) 123 { 124 int *aio_ret = opaque; 125 *aio_ret = ret; 126 } 127 128 typedef struct CallInCoroutineData { 129 void (*entry)(void); 130 bool done; 131 } CallInCoroutineData; 132 133 static coroutine_fn void call_in_coroutine_entry(void *opaque) 134 { 135 CallInCoroutineData *data = opaque; 136 137 data->entry(); 138 data->done = true; 139 } 140 141 static void call_in_coroutine(void (*entry)(void)) 142 { 143 Coroutine *co; 144 CallInCoroutineData data = { 145 .entry = entry, 146 .done = false, 147 }; 148 149 co = qemu_coroutine_create(call_in_coroutine_entry, &data); 150 qemu_coroutine_enter(co); 151 while (!data.done) { 152 aio_poll(qemu_get_aio_context(), true); 153 } 154 } 155 156 enum drain_type { 157 BDRV_DRAIN_ALL, 158 BDRV_DRAIN, 159 DRAIN_TYPE_MAX, 160 }; 161 162 static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs) 163 { 164 switch (drain_type) { 165 case BDRV_DRAIN_ALL: bdrv_drain_all_begin(); break; 166 case BDRV_DRAIN: bdrv_drained_begin(bs); break; 167 default: g_assert_not_reached(); 168 } 169 } 170 171 static void do_drain_end(enum drain_type drain_type, BlockDriverState *bs) 172 { 173 switch (drain_type) { 174 case BDRV_DRAIN_ALL: bdrv_drain_all_end(); break; 175 case BDRV_DRAIN: bdrv_drained_end(bs); break; 176 default: g_assert_not_reached(); 177 } 178 } 179 180 static void do_drain_begin_unlocked(enum drain_type drain_type, BlockDriverState *bs) 181 { 182 if (drain_type != BDRV_DRAIN_ALL) { 183 aio_context_acquire(bdrv_get_aio_context(bs)); 184 } 185 do_drain_begin(drain_type, bs); 186 if (drain_type != BDRV_DRAIN_ALL) { 187 aio_context_release(bdrv_get_aio_context(bs)); 188 } 189 } 190 191 static BlockBackend * no_coroutine_fn test_setup(void) 192 { 193 BlockBackend *blk; 194 BlockDriverState *bs, *backing; 195 196 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 197 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 198 &error_abort); 199 blk_insert_bs(blk, bs, &error_abort); 200 201 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 202 bdrv_set_backing_hd(bs, backing, &error_abort); 203 204 bdrv_unref(backing); 205 bdrv_unref(bs); 206 207 return blk; 208 } 209 210 static void do_drain_end_unlocked(enum drain_type drain_type, BlockDriverState *bs) 211 { 212 if (drain_type != BDRV_DRAIN_ALL) { 213 aio_context_acquire(bdrv_get_aio_context(bs)); 214 } 215 do_drain_end(drain_type, bs); 216 if (drain_type != BDRV_DRAIN_ALL) { 217 aio_context_release(bdrv_get_aio_context(bs)); 218 } 219 } 220 221 static void test_drv_cb_common(BlockBackend *blk, enum drain_type drain_type, 222 bool recursive) 223 { 224 BlockDriverState *bs = blk_bs(blk); 225 BlockDriverState *backing = bs->backing->bs; 226 BDRVTestState *s, *backing_s; 227 BlockAIOCB *acb; 228 int aio_ret; 229 230 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 231 232 s = bs->opaque; 233 backing_s = backing->opaque; 234 235 /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */ 236 g_assert_cmpint(s->drain_count, ==, 0); 237 g_assert_cmpint(backing_s->drain_count, ==, 0); 238 239 do_drain_begin(drain_type, bs); 240 241 g_assert_cmpint(s->drain_count, ==, 1); 242 g_assert_cmpint(backing_s->drain_count, ==, !!recursive); 243 244 do_drain_end(drain_type, bs); 245 246 g_assert_cmpint(s->drain_count, ==, 0); 247 g_assert_cmpint(backing_s->drain_count, ==, 0); 248 249 /* Now do the same while a request is pending */ 250 aio_ret = -EINPROGRESS; 251 acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); 252 g_assert(acb != NULL); 253 g_assert_cmpint(aio_ret, ==, -EINPROGRESS); 254 255 g_assert_cmpint(s->drain_count, ==, 0); 256 g_assert_cmpint(backing_s->drain_count, ==, 0); 257 258 do_drain_begin(drain_type, bs); 259 260 g_assert_cmpint(aio_ret, ==, 0); 261 g_assert_cmpint(s->drain_count, ==, 1); 262 g_assert_cmpint(backing_s->drain_count, ==, !!recursive); 263 264 do_drain_end(drain_type, bs); 265 266 g_assert_cmpint(s->drain_count, ==, 0); 267 g_assert_cmpint(backing_s->drain_count, ==, 0); 268 } 269 270 static void test_drv_cb_drain_all(void) 271 { 272 BlockBackend *blk = test_setup(); 273 test_drv_cb_common(blk, BDRV_DRAIN_ALL, true); 274 blk_unref(blk); 275 } 276 277 static void test_drv_cb_drain(void) 278 { 279 BlockBackend *blk = test_setup(); 280 test_drv_cb_common(blk, BDRV_DRAIN, false); 281 blk_unref(blk); 282 } 283 284 static void coroutine_fn test_drv_cb_co_drain_all_entry(void) 285 { 286 BlockBackend *blk = blk_all_next(NULL); 287 test_drv_cb_common(blk, BDRV_DRAIN_ALL, true); 288 } 289 290 static void test_drv_cb_co_drain_all(void) 291 { 292 BlockBackend *blk = test_setup(); 293 call_in_coroutine(test_drv_cb_co_drain_all_entry); 294 blk_unref(blk); 295 } 296 297 static void coroutine_fn test_drv_cb_co_drain_entry(void) 298 { 299 BlockBackend *blk = blk_all_next(NULL); 300 test_drv_cb_common(blk, BDRV_DRAIN, false); 301 } 302 303 static void test_drv_cb_co_drain(void) 304 { 305 BlockBackend *blk = test_setup(); 306 call_in_coroutine(test_drv_cb_co_drain_entry); 307 blk_unref(blk); 308 } 309 310 static void test_quiesce_common(BlockBackend *blk, enum drain_type drain_type, 311 bool recursive) 312 { 313 BlockDriverState *bs = blk_bs(blk); 314 BlockDriverState *backing = bs->backing->bs; 315 316 g_assert_cmpint(bs->quiesce_counter, ==, 0); 317 g_assert_cmpint(backing->quiesce_counter, ==, 0); 318 319 do_drain_begin(drain_type, bs); 320 321 if (drain_type == BDRV_DRAIN_ALL) { 322 g_assert_cmpint(bs->quiesce_counter, ==, 2); 323 } else { 324 g_assert_cmpint(bs->quiesce_counter, ==, 1); 325 } 326 g_assert_cmpint(backing->quiesce_counter, ==, !!recursive); 327 328 do_drain_end(drain_type, bs); 329 330 g_assert_cmpint(bs->quiesce_counter, ==, 0); 331 g_assert_cmpint(backing->quiesce_counter, ==, 0); 332 } 333 334 static void test_quiesce_drain_all(void) 335 { 336 BlockBackend *blk = test_setup(); 337 test_quiesce_common(blk, BDRV_DRAIN_ALL, true); 338 blk_unref(blk); 339 } 340 341 static void test_quiesce_drain(void) 342 { 343 BlockBackend *blk = test_setup(); 344 test_quiesce_common(blk, BDRV_DRAIN, false); 345 blk_unref(blk); 346 } 347 348 static void coroutine_fn test_quiesce_co_drain_all_entry(void) 349 { 350 BlockBackend *blk = blk_all_next(NULL); 351 test_quiesce_common(blk, BDRV_DRAIN_ALL, true); 352 } 353 354 static void test_quiesce_co_drain_all(void) 355 { 356 BlockBackend *blk = test_setup(); 357 call_in_coroutine(test_quiesce_co_drain_all_entry); 358 blk_unref(blk); 359 } 360 361 static void coroutine_fn test_quiesce_co_drain_entry(void) 362 { 363 BlockBackend *blk = blk_all_next(NULL); 364 test_quiesce_common(blk, BDRV_DRAIN, false); 365 } 366 367 static void test_quiesce_co_drain(void) 368 { 369 BlockBackend *blk = test_setup(); 370 call_in_coroutine(test_quiesce_co_drain_entry); 371 blk_unref(blk); 372 } 373 374 static void test_nested(void) 375 { 376 BlockBackend *blk; 377 BlockDriverState *bs, *backing; 378 BDRVTestState *s, *backing_s; 379 enum drain_type outer, inner; 380 381 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 382 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 383 &error_abort); 384 s = bs->opaque; 385 blk_insert_bs(blk, bs, &error_abort); 386 387 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 388 backing_s = backing->opaque; 389 bdrv_set_backing_hd(bs, backing, &error_abort); 390 391 for (outer = 0; outer < DRAIN_TYPE_MAX; outer++) { 392 for (inner = 0; inner < DRAIN_TYPE_MAX; inner++) { 393 int backing_quiesce = (outer == BDRV_DRAIN_ALL) + 394 (inner == BDRV_DRAIN_ALL); 395 396 g_assert_cmpint(bs->quiesce_counter, ==, 0); 397 g_assert_cmpint(backing->quiesce_counter, ==, 0); 398 g_assert_cmpint(s->drain_count, ==, 0); 399 g_assert_cmpint(backing_s->drain_count, ==, 0); 400 401 do_drain_begin(outer, bs); 402 do_drain_begin(inner, bs); 403 404 g_assert_cmpint(bs->quiesce_counter, ==, 2 + !!backing_quiesce); 405 g_assert_cmpint(backing->quiesce_counter, ==, backing_quiesce); 406 g_assert_cmpint(s->drain_count, ==, 1); 407 g_assert_cmpint(backing_s->drain_count, ==, !!backing_quiesce); 408 409 do_drain_end(inner, bs); 410 do_drain_end(outer, bs); 411 412 g_assert_cmpint(bs->quiesce_counter, ==, 0); 413 g_assert_cmpint(backing->quiesce_counter, ==, 0); 414 g_assert_cmpint(s->drain_count, ==, 0); 415 g_assert_cmpint(backing_s->drain_count, ==, 0); 416 } 417 } 418 419 bdrv_unref(backing); 420 bdrv_unref(bs); 421 blk_unref(blk); 422 } 423 424 static void test_graph_change_drain_all(void) 425 { 426 BlockBackend *blk_a, *blk_b; 427 BlockDriverState *bs_a, *bs_b; 428 BDRVTestState *a_s, *b_s; 429 430 /* Create node A with a BlockBackend */ 431 blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 432 bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR, 433 &error_abort); 434 a_s = bs_a->opaque; 435 blk_insert_bs(blk_a, bs_a, &error_abort); 436 437 g_assert_cmpint(bs_a->quiesce_counter, ==, 0); 438 g_assert_cmpint(a_s->drain_count, ==, 0); 439 440 /* Call bdrv_drain_all_begin() */ 441 bdrv_drain_all_begin(); 442 443 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 444 g_assert_cmpint(a_s->drain_count, ==, 1); 445 446 /* Create node B with a BlockBackend */ 447 blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 448 bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR, 449 &error_abort); 450 b_s = bs_b->opaque; 451 blk_insert_bs(blk_b, bs_b, &error_abort); 452 453 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 454 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 455 g_assert_cmpint(a_s->drain_count, ==, 1); 456 g_assert_cmpint(b_s->drain_count, ==, 1); 457 458 /* Unref and finally delete node A */ 459 blk_unref(blk_a); 460 461 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 462 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 463 g_assert_cmpint(a_s->drain_count, ==, 1); 464 g_assert_cmpint(b_s->drain_count, ==, 1); 465 466 bdrv_unref(bs_a); 467 468 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 469 g_assert_cmpint(b_s->drain_count, ==, 1); 470 471 /* End the drained section */ 472 bdrv_drain_all_end(); 473 474 g_assert_cmpint(bs_b->quiesce_counter, ==, 0); 475 g_assert_cmpint(b_s->drain_count, ==, 0); 476 g_assert_cmpint(qemu_get_aio_context()->external_disable_cnt, ==, 0); 477 478 bdrv_unref(bs_b); 479 blk_unref(blk_b); 480 } 481 482 struct test_iothread_data { 483 BlockDriverState *bs; 484 enum drain_type drain_type; 485 int *aio_ret; 486 }; 487 488 static void test_iothread_drain_entry(void *opaque) 489 { 490 struct test_iothread_data *data = opaque; 491 492 aio_context_acquire(bdrv_get_aio_context(data->bs)); 493 do_drain_begin(data->drain_type, data->bs); 494 g_assert_cmpint(*data->aio_ret, ==, 0); 495 do_drain_end(data->drain_type, data->bs); 496 aio_context_release(bdrv_get_aio_context(data->bs)); 497 498 qemu_event_set(&done_event); 499 } 500 501 static void test_iothread_aio_cb(void *opaque, int ret) 502 { 503 int *aio_ret = opaque; 504 *aio_ret = ret; 505 qemu_event_set(&done_event); 506 } 507 508 static void test_iothread_main_thread_bh(void *opaque) 509 { 510 struct test_iothread_data *data = opaque; 511 512 /* Test that the AioContext is not yet locked in a random BH that is 513 * executed during drain, otherwise this would deadlock. */ 514 aio_context_acquire(bdrv_get_aio_context(data->bs)); 515 bdrv_flush(data->bs); 516 aio_context_release(bdrv_get_aio_context(data->bs)); 517 } 518 519 /* 520 * Starts an AIO request on a BDS that runs in the AioContext of iothread 1. 521 * The request involves a BH on iothread 2 before it can complete. 522 * 523 * @drain_thread = 0 means that do_drain_begin/end are called from the main 524 * thread, @drain_thread = 1 means that they are called from iothread 1. Drain 525 * for this BDS cannot be called from iothread 2 because only the main thread 526 * may do cross-AioContext polling. 527 */ 528 static void test_iothread_common(enum drain_type drain_type, int drain_thread) 529 { 530 BlockBackend *blk; 531 BlockDriverState *bs; 532 BDRVTestState *s; 533 BlockAIOCB *acb; 534 int aio_ret; 535 struct test_iothread_data data; 536 537 IOThread *a = iothread_new(); 538 IOThread *b = iothread_new(); 539 AioContext *ctx_a = iothread_get_aio_context(a); 540 AioContext *ctx_b = iothread_get_aio_context(b); 541 542 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 543 544 /* bdrv_drain_all() may only be called from the main loop thread */ 545 if (drain_type == BDRV_DRAIN_ALL && drain_thread != 0) { 546 goto out; 547 } 548 549 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 550 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 551 &error_abort); 552 s = bs->opaque; 553 blk_insert_bs(blk, bs, &error_abort); 554 blk_set_disable_request_queuing(blk, true); 555 556 blk_set_aio_context(blk, ctx_a, &error_abort); 557 aio_context_acquire(ctx_a); 558 559 s->bh_indirection_ctx = ctx_b; 560 561 aio_ret = -EINPROGRESS; 562 qemu_event_reset(&done_event); 563 564 if (drain_thread == 0) { 565 acb = blk_aio_preadv(blk, 0, &qiov, 0, test_iothread_aio_cb, &aio_ret); 566 } else { 567 acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); 568 } 569 g_assert(acb != NULL); 570 g_assert_cmpint(aio_ret, ==, -EINPROGRESS); 571 572 aio_context_release(ctx_a); 573 574 data = (struct test_iothread_data) { 575 .bs = bs, 576 .drain_type = drain_type, 577 .aio_ret = &aio_ret, 578 }; 579 580 switch (drain_thread) { 581 case 0: 582 if (drain_type != BDRV_DRAIN_ALL) { 583 aio_context_acquire(ctx_a); 584 } 585 586 aio_bh_schedule_oneshot(ctx_a, test_iothread_main_thread_bh, &data); 587 588 /* The request is running on the IOThread a. Draining its block device 589 * will make sure that it has completed as far as the BDS is concerned, 590 * but the drain in this thread can continue immediately after 591 * bdrv_dec_in_flight() and aio_ret might be assigned only slightly 592 * later. */ 593 do_drain_begin(drain_type, bs); 594 g_assert_cmpint(bs->in_flight, ==, 0); 595 596 if (drain_type != BDRV_DRAIN_ALL) { 597 aio_context_release(ctx_a); 598 } 599 qemu_event_wait(&done_event); 600 if (drain_type != BDRV_DRAIN_ALL) { 601 aio_context_acquire(ctx_a); 602 } 603 604 g_assert_cmpint(aio_ret, ==, 0); 605 do_drain_end(drain_type, bs); 606 607 if (drain_type != BDRV_DRAIN_ALL) { 608 aio_context_release(ctx_a); 609 } 610 break; 611 case 1: 612 aio_bh_schedule_oneshot(ctx_a, test_iothread_drain_entry, &data); 613 qemu_event_wait(&done_event); 614 break; 615 default: 616 g_assert_not_reached(); 617 } 618 619 aio_context_acquire(ctx_a); 620 blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort); 621 aio_context_release(ctx_a); 622 623 bdrv_unref(bs); 624 blk_unref(blk); 625 626 out: 627 iothread_join(a); 628 iothread_join(b); 629 } 630 631 static void test_iothread_drain_all(void) 632 { 633 test_iothread_common(BDRV_DRAIN_ALL, 0); 634 test_iothread_common(BDRV_DRAIN_ALL, 1); 635 } 636 637 static void test_iothread_drain(void) 638 { 639 test_iothread_common(BDRV_DRAIN, 0); 640 test_iothread_common(BDRV_DRAIN, 1); 641 } 642 643 644 typedef struct TestBlockJob { 645 BlockJob common; 646 BlockDriverState *bs; 647 int run_ret; 648 int prepare_ret; 649 bool running; 650 bool should_complete; 651 } TestBlockJob; 652 653 static int test_job_prepare(Job *job) 654 { 655 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 656 657 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 658 bdrv_flush(s->bs); 659 return s->prepare_ret; 660 } 661 662 static void test_job_commit(Job *job) 663 { 664 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 665 666 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 667 bdrv_flush(s->bs); 668 } 669 670 static void test_job_abort(Job *job) 671 { 672 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 673 674 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 675 bdrv_flush(s->bs); 676 } 677 678 static int coroutine_fn test_job_run(Job *job, Error **errp) 679 { 680 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 681 682 /* We are running the actual job code past the pause point in 683 * job_co_entry(). */ 684 s->running = true; 685 686 job_transition_to_ready(&s->common.job); 687 while (!s->should_complete) { 688 /* Avoid job_sleep_ns() because it marks the job as !busy. We want to 689 * emulate some actual activity (probably some I/O) here so that drain 690 * has to wait for this activity to stop. */ 691 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); 692 693 job_pause_point(&s->common.job); 694 } 695 696 return s->run_ret; 697 } 698 699 static void test_job_complete(Job *job, Error **errp) 700 { 701 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 702 s->should_complete = true; 703 } 704 705 BlockJobDriver test_job_driver = { 706 .job_driver = { 707 .instance_size = sizeof(TestBlockJob), 708 .free = block_job_free, 709 .user_resume = block_job_user_resume, 710 .run = test_job_run, 711 .complete = test_job_complete, 712 .prepare = test_job_prepare, 713 .commit = test_job_commit, 714 .abort = test_job_abort, 715 }, 716 }; 717 718 enum test_job_result { 719 TEST_JOB_SUCCESS, 720 TEST_JOB_FAIL_RUN, 721 TEST_JOB_FAIL_PREPARE, 722 }; 723 724 enum test_job_drain_node { 725 TEST_JOB_DRAIN_SRC, 726 TEST_JOB_DRAIN_SRC_CHILD, 727 }; 728 729 static void test_blockjob_common_drain_node(enum drain_type drain_type, 730 bool use_iothread, 731 enum test_job_result result, 732 enum test_job_drain_node drain_node) 733 { 734 BlockBackend *blk_src, *blk_target; 735 BlockDriverState *src, *src_backing, *src_overlay, *target, *drain_bs; 736 BlockJob *job; 737 TestBlockJob *tjob; 738 IOThread *iothread = NULL; 739 AioContext *ctx; 740 int ret; 741 742 src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR, 743 &error_abort); 744 src_backing = bdrv_new_open_driver(&bdrv_test, "source-backing", 745 BDRV_O_RDWR, &error_abort); 746 src_overlay = bdrv_new_open_driver(&bdrv_test, "source-overlay", 747 BDRV_O_RDWR, &error_abort); 748 749 bdrv_set_backing_hd(src_overlay, src, &error_abort); 750 bdrv_unref(src); 751 bdrv_set_backing_hd(src, src_backing, &error_abort); 752 bdrv_unref(src_backing); 753 754 blk_src = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 755 blk_insert_bs(blk_src, src_overlay, &error_abort); 756 757 switch (drain_node) { 758 case TEST_JOB_DRAIN_SRC: 759 drain_bs = src; 760 break; 761 case TEST_JOB_DRAIN_SRC_CHILD: 762 drain_bs = src_backing; 763 break; 764 default: 765 g_assert_not_reached(); 766 } 767 768 if (use_iothread) { 769 iothread = iothread_new(); 770 ctx = iothread_get_aio_context(iothread); 771 blk_set_aio_context(blk_src, ctx, &error_abort); 772 } else { 773 ctx = qemu_get_aio_context(); 774 } 775 776 target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR, 777 &error_abort); 778 blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 779 blk_insert_bs(blk_target, target, &error_abort); 780 blk_set_allow_aio_context_change(blk_target, true); 781 782 aio_context_acquire(ctx); 783 tjob = block_job_create("job0", &test_job_driver, NULL, src, 784 0, BLK_PERM_ALL, 785 0, 0, NULL, NULL, &error_abort); 786 tjob->bs = src; 787 job = &tjob->common; 788 block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort); 789 790 switch (result) { 791 case TEST_JOB_SUCCESS: 792 break; 793 case TEST_JOB_FAIL_RUN: 794 tjob->run_ret = -EIO; 795 break; 796 case TEST_JOB_FAIL_PREPARE: 797 tjob->prepare_ret = -EIO; 798 break; 799 } 800 aio_context_release(ctx); 801 802 job_start(&job->job); 803 804 if (use_iothread) { 805 /* job_co_entry() is run in the I/O thread, wait for the actual job 806 * code to start (we don't want to catch the job in the pause point in 807 * job_co_entry(). */ 808 while (!tjob->running) { 809 aio_poll(qemu_get_aio_context(), false); 810 } 811 } 812 813 WITH_JOB_LOCK_GUARD() { 814 g_assert_cmpint(job->job.pause_count, ==, 0); 815 g_assert_false(job->job.paused); 816 g_assert_true(tjob->running); 817 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 818 } 819 820 do_drain_begin_unlocked(drain_type, drain_bs); 821 822 WITH_JOB_LOCK_GUARD() { 823 if (drain_type == BDRV_DRAIN_ALL) { 824 /* bdrv_drain_all() drains both src and target */ 825 g_assert_cmpint(job->job.pause_count, ==, 2); 826 } else { 827 g_assert_cmpint(job->job.pause_count, ==, 1); 828 } 829 g_assert_true(job->job.paused); 830 g_assert_false(job->job.busy); /* The job is paused */ 831 } 832 833 do_drain_end_unlocked(drain_type, drain_bs); 834 835 if (use_iothread) { 836 /* 837 * Here we are waiting for the paused status to change, 838 * so don't bother protecting the read every time. 839 * 840 * paused is reset in the I/O thread, wait for it 841 */ 842 while (job->job.paused) { 843 aio_poll(qemu_get_aio_context(), false); 844 } 845 } 846 847 WITH_JOB_LOCK_GUARD() { 848 g_assert_cmpint(job->job.pause_count, ==, 0); 849 g_assert_false(job->job.paused); 850 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 851 } 852 853 do_drain_begin_unlocked(drain_type, target); 854 855 WITH_JOB_LOCK_GUARD() { 856 if (drain_type == BDRV_DRAIN_ALL) { 857 /* bdrv_drain_all() drains both src and target */ 858 g_assert_cmpint(job->job.pause_count, ==, 2); 859 } else { 860 g_assert_cmpint(job->job.pause_count, ==, 1); 861 } 862 g_assert_true(job->job.paused); 863 g_assert_false(job->job.busy); /* The job is paused */ 864 } 865 866 do_drain_end_unlocked(drain_type, target); 867 868 if (use_iothread) { 869 /* 870 * Here we are waiting for the paused status to change, 871 * so don't bother protecting the read every time. 872 * 873 * paused is reset in the I/O thread, wait for it 874 */ 875 while (job->job.paused) { 876 aio_poll(qemu_get_aio_context(), false); 877 } 878 } 879 880 WITH_JOB_LOCK_GUARD() { 881 g_assert_cmpint(job->job.pause_count, ==, 0); 882 g_assert_false(job->job.paused); 883 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 884 } 885 886 WITH_JOB_LOCK_GUARD() { 887 ret = job_complete_sync_locked(&job->job, &error_abort); 888 } 889 g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO)); 890 891 aio_context_acquire(ctx); 892 if (use_iothread) { 893 blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort); 894 assert(blk_get_aio_context(blk_target) == qemu_get_aio_context()); 895 } 896 aio_context_release(ctx); 897 898 blk_unref(blk_src); 899 blk_unref(blk_target); 900 bdrv_unref(src_overlay); 901 bdrv_unref(target); 902 903 if (iothread) { 904 iothread_join(iothread); 905 } 906 } 907 908 static void test_blockjob_common(enum drain_type drain_type, bool use_iothread, 909 enum test_job_result result) 910 { 911 test_blockjob_common_drain_node(drain_type, use_iothread, result, 912 TEST_JOB_DRAIN_SRC); 913 test_blockjob_common_drain_node(drain_type, use_iothread, result, 914 TEST_JOB_DRAIN_SRC_CHILD); 915 } 916 917 static void test_blockjob_drain_all(void) 918 { 919 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS); 920 } 921 922 static void test_blockjob_drain(void) 923 { 924 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_SUCCESS); 925 } 926 927 static void test_blockjob_error_drain_all(void) 928 { 929 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_RUN); 930 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_PREPARE); 931 } 932 933 static void test_blockjob_error_drain(void) 934 { 935 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_RUN); 936 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_PREPARE); 937 } 938 939 static void test_blockjob_iothread_drain_all(void) 940 { 941 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_SUCCESS); 942 } 943 944 static void test_blockjob_iothread_drain(void) 945 { 946 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_SUCCESS); 947 } 948 949 static void test_blockjob_iothread_error_drain_all(void) 950 { 951 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_RUN); 952 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_PREPARE); 953 } 954 955 static void test_blockjob_iothread_error_drain(void) 956 { 957 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_RUN); 958 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_PREPARE); 959 } 960 961 962 typedef struct BDRVTestTopState { 963 BdrvChild *wait_child; 964 } BDRVTestTopState; 965 966 static void bdrv_test_top_close(BlockDriverState *bs) 967 { 968 BdrvChild *c, *next_c; 969 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 970 bdrv_unref_child(bs, c); 971 } 972 } 973 974 static int coroutine_fn GRAPH_RDLOCK 975 bdrv_test_top_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 976 QEMUIOVector *qiov, BdrvRequestFlags flags) 977 { 978 BDRVTestTopState *tts = bs->opaque; 979 return bdrv_co_preadv(tts->wait_child, offset, bytes, qiov, flags); 980 } 981 982 static BlockDriver bdrv_test_top_driver = { 983 .format_name = "test_top_driver", 984 .instance_size = sizeof(BDRVTestTopState), 985 986 .bdrv_close = bdrv_test_top_close, 987 .bdrv_co_preadv = bdrv_test_top_co_preadv, 988 989 .bdrv_child_perm = bdrv_default_perms, 990 }; 991 992 typedef struct TestCoDeleteByDrainData { 993 BlockBackend *blk; 994 bool detach_instead_of_delete; 995 bool done; 996 } TestCoDeleteByDrainData; 997 998 static void coroutine_fn test_co_delete_by_drain(void *opaque) 999 { 1000 TestCoDeleteByDrainData *dbdd = opaque; 1001 BlockBackend *blk = dbdd->blk; 1002 BlockDriverState *bs = blk_bs(blk); 1003 BDRVTestTopState *tts = bs->opaque; 1004 void *buffer = g_malloc(65536); 1005 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buffer, 65536); 1006 1007 GRAPH_RDLOCK_GUARD(); 1008 1009 /* Pretend some internal write operation from parent to child. 1010 * Important: We have to read from the child, not from the parent! 1011 * Draining works by first propagating it all up the tree to the 1012 * root and then waiting for drainage from root to the leaves 1013 * (protocol nodes). If we have a request waiting on the root, 1014 * everything will be drained before we go back down the tree, but 1015 * we do not want that. We want to be in the middle of draining 1016 * when this following requests returns. */ 1017 bdrv_co_preadv(tts->wait_child, 0, 65536, &qiov, 0); 1018 1019 g_assert_cmpint(bs->refcnt, ==, 1); 1020 1021 if (!dbdd->detach_instead_of_delete) { 1022 blk_unref(blk); 1023 } else { 1024 BdrvChild *c, *next_c; 1025 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 1026 bdrv_unref_child(bs, c); 1027 } 1028 } 1029 1030 dbdd->done = true; 1031 g_free(buffer); 1032 } 1033 1034 /** 1035 * Test what happens when some BDS has some children, you drain one of 1036 * them and this results in the BDS being deleted. 1037 * 1038 * If @detach_instead_of_delete is set, the BDS is not going to be 1039 * deleted but will only detach all of its children. 1040 */ 1041 static void do_test_delete_by_drain(bool detach_instead_of_delete, 1042 enum drain_type drain_type) 1043 { 1044 BlockBackend *blk; 1045 BlockDriverState *bs, *child_bs, *null_bs; 1046 BDRVTestTopState *tts; 1047 TestCoDeleteByDrainData dbdd; 1048 Coroutine *co; 1049 1050 bs = bdrv_new_open_driver(&bdrv_test_top_driver, "top", BDRV_O_RDWR, 1051 &error_abort); 1052 bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1053 tts = bs->opaque; 1054 1055 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1056 &error_abort); 1057 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, 1058 BDRV_CHILD_DATA, &error_abort); 1059 1060 /* This child will be the one to pass to requests through to, and 1061 * it will stall until a drain occurs */ 1062 child_bs = bdrv_new_open_driver(&bdrv_test, "child", BDRV_O_RDWR, 1063 &error_abort); 1064 child_bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1065 /* Takes our reference to child_bs */ 1066 tts->wait_child = bdrv_attach_child(bs, child_bs, "wait-child", 1067 &child_of_bds, 1068 BDRV_CHILD_DATA | BDRV_CHILD_PRIMARY, 1069 &error_abort); 1070 1071 /* This child is just there to be deleted 1072 * (for detach_instead_of_delete == true) */ 1073 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1074 &error_abort); 1075 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, BDRV_CHILD_DATA, 1076 &error_abort); 1077 1078 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1079 blk_insert_bs(blk, bs, &error_abort); 1080 1081 /* Referenced by blk now */ 1082 bdrv_unref(bs); 1083 1084 g_assert_cmpint(bs->refcnt, ==, 1); 1085 g_assert_cmpint(child_bs->refcnt, ==, 1); 1086 g_assert_cmpint(null_bs->refcnt, ==, 1); 1087 1088 1089 dbdd = (TestCoDeleteByDrainData){ 1090 .blk = blk, 1091 .detach_instead_of_delete = detach_instead_of_delete, 1092 .done = false, 1093 }; 1094 co = qemu_coroutine_create(test_co_delete_by_drain, &dbdd); 1095 qemu_coroutine_enter(co); 1096 1097 /* Drain the child while the read operation is still pending. 1098 * This should result in the operation finishing and 1099 * test_co_delete_by_drain() resuming. Thus, @bs will be deleted 1100 * and the coroutine will exit while this drain operation is still 1101 * in progress. */ 1102 switch (drain_type) { 1103 case BDRV_DRAIN: 1104 bdrv_ref(child_bs); 1105 bdrv_drain(child_bs); 1106 bdrv_unref(child_bs); 1107 break; 1108 case BDRV_DRAIN_ALL: 1109 bdrv_drain_all_begin(); 1110 bdrv_drain_all_end(); 1111 break; 1112 default: 1113 g_assert_not_reached(); 1114 } 1115 1116 while (!dbdd.done) { 1117 aio_poll(qemu_get_aio_context(), true); 1118 } 1119 1120 if (detach_instead_of_delete) { 1121 /* Here, the reference has not passed over to the coroutine, 1122 * so we have to delete the BB ourselves */ 1123 blk_unref(blk); 1124 } 1125 } 1126 1127 static void test_delete_by_drain(void) 1128 { 1129 do_test_delete_by_drain(false, BDRV_DRAIN); 1130 } 1131 1132 static void test_detach_by_drain_all(void) 1133 { 1134 do_test_delete_by_drain(true, BDRV_DRAIN_ALL); 1135 } 1136 1137 static void test_detach_by_drain(void) 1138 { 1139 do_test_delete_by_drain(true, BDRV_DRAIN); 1140 } 1141 1142 1143 struct detach_by_parent_data { 1144 BlockDriverState *parent_b; 1145 BdrvChild *child_b; 1146 BlockDriverState *c; 1147 BdrvChild *child_c; 1148 bool by_parent_cb; 1149 bool detach_on_drain; 1150 }; 1151 static struct detach_by_parent_data detach_by_parent_data; 1152 1153 static void detach_indirect_bh(void *opaque) 1154 { 1155 struct detach_by_parent_data *data = opaque; 1156 1157 bdrv_dec_in_flight(data->child_b->bs); 1158 bdrv_unref_child(data->parent_b, data->child_b); 1159 1160 bdrv_ref(data->c); 1161 data->child_c = bdrv_attach_child(data->parent_b, data->c, "PB-C", 1162 &child_of_bds, BDRV_CHILD_DATA, 1163 &error_abort); 1164 } 1165 1166 static void detach_by_parent_aio_cb(void *opaque, int ret) 1167 { 1168 struct detach_by_parent_data *data = &detach_by_parent_data; 1169 1170 g_assert_cmpint(ret, ==, 0); 1171 if (data->by_parent_cb) { 1172 bdrv_inc_in_flight(data->child_b->bs); 1173 detach_indirect_bh(data); 1174 } 1175 } 1176 1177 static void detach_by_driver_cb_drained_begin(BdrvChild *child) 1178 { 1179 struct detach_by_parent_data *data = &detach_by_parent_data; 1180 1181 if (!data->detach_on_drain) { 1182 return; 1183 } 1184 data->detach_on_drain = false; 1185 1186 bdrv_inc_in_flight(data->child_b->bs); 1187 aio_bh_schedule_oneshot(qemu_get_current_aio_context(), 1188 detach_indirect_bh, &detach_by_parent_data); 1189 child_of_bds.drained_begin(child); 1190 } 1191 1192 static BdrvChildClass detach_by_driver_cb_class; 1193 1194 /* 1195 * Initial graph: 1196 * 1197 * PA PB 1198 * \ / \ 1199 * A B C 1200 * 1201 * by_parent_cb == true: Test that parent callbacks don't poll 1202 * 1203 * PA has a pending write request whose callback changes the child nodes of 1204 * PB: It removes B and adds C instead. The subtree of PB is drained, which 1205 * will indirectly drain the write request, too. 1206 * 1207 * by_parent_cb == false: Test that bdrv_drain_invoke() doesn't poll 1208 * 1209 * PA's BdrvChildClass has a .drained_begin callback that schedules a BH 1210 * that does the same graph change. If bdrv_drain_invoke() calls it, the 1211 * state is messed up, but if it is only polled in the single 1212 * BDRV_POLL_WHILE() at the end of the drain, this should work fine. 1213 */ 1214 static void test_detach_indirect(bool by_parent_cb) 1215 { 1216 BlockBackend *blk; 1217 BlockDriverState *parent_a, *parent_b, *a, *b, *c; 1218 BdrvChild *child_a, *child_b; 1219 BlockAIOCB *acb; 1220 1221 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 1222 1223 if (!by_parent_cb) { 1224 detach_by_driver_cb_class = child_of_bds; 1225 detach_by_driver_cb_class.drained_begin = 1226 detach_by_driver_cb_drained_begin; 1227 detach_by_driver_cb_class.drained_end = NULL; 1228 detach_by_driver_cb_class.drained_poll = NULL; 1229 } 1230 1231 detach_by_parent_data = (struct detach_by_parent_data) { 1232 .detach_on_drain = false, 1233 }; 1234 1235 /* Create all involved nodes */ 1236 parent_a = bdrv_new_open_driver(&bdrv_test, "parent-a", BDRV_O_RDWR, 1237 &error_abort); 1238 parent_b = bdrv_new_open_driver(&bdrv_test, "parent-b", 0, 1239 &error_abort); 1240 1241 a = bdrv_new_open_driver(&bdrv_test, "a", BDRV_O_RDWR, &error_abort); 1242 b = bdrv_new_open_driver(&bdrv_test, "b", BDRV_O_RDWR, &error_abort); 1243 c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort); 1244 1245 /* blk is a BB for parent-a */ 1246 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1247 blk_insert_bs(blk, parent_a, &error_abort); 1248 bdrv_unref(parent_a); 1249 1250 /* If we want to get bdrv_drain_invoke() to call aio_poll(), the driver 1251 * callback must not return immediately. */ 1252 if (!by_parent_cb) { 1253 BDRVTestState *s = parent_a->opaque; 1254 s->sleep_in_drain_begin = true; 1255 } 1256 1257 /* Set child relationships */ 1258 bdrv_ref(b); 1259 bdrv_ref(a); 1260 child_b = bdrv_attach_child(parent_b, b, "PB-B", &child_of_bds, 1261 BDRV_CHILD_DATA, &error_abort); 1262 child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_of_bds, 1263 BDRV_CHILD_COW, &error_abort); 1264 1265 bdrv_ref(a); 1266 bdrv_attach_child(parent_a, a, "PA-A", 1267 by_parent_cb ? &child_of_bds : &detach_by_driver_cb_class, 1268 BDRV_CHILD_DATA, &error_abort); 1269 1270 g_assert_cmpint(parent_a->refcnt, ==, 1); 1271 g_assert_cmpint(parent_b->refcnt, ==, 1); 1272 g_assert_cmpint(a->refcnt, ==, 3); 1273 g_assert_cmpint(b->refcnt, ==, 2); 1274 g_assert_cmpint(c->refcnt, ==, 1); 1275 1276 g_assert(QLIST_FIRST(&parent_b->children) == child_a); 1277 g_assert(QLIST_NEXT(child_a, next) == child_b); 1278 g_assert(QLIST_NEXT(child_b, next) == NULL); 1279 1280 /* Start the evil write request */ 1281 detach_by_parent_data = (struct detach_by_parent_data) { 1282 .parent_b = parent_b, 1283 .child_b = child_b, 1284 .c = c, 1285 .by_parent_cb = by_parent_cb, 1286 .detach_on_drain = true, 1287 }; 1288 acb = blk_aio_preadv(blk, 0, &qiov, 0, detach_by_parent_aio_cb, NULL); 1289 g_assert(acb != NULL); 1290 1291 /* Drain and check the expected result */ 1292 bdrv_drained_begin(parent_b); 1293 bdrv_drained_begin(a); 1294 bdrv_drained_begin(b); 1295 bdrv_drained_begin(c); 1296 1297 g_assert(detach_by_parent_data.child_c != NULL); 1298 1299 g_assert_cmpint(parent_a->refcnt, ==, 1); 1300 g_assert_cmpint(parent_b->refcnt, ==, 1); 1301 g_assert_cmpint(a->refcnt, ==, 3); 1302 g_assert_cmpint(b->refcnt, ==, 1); 1303 g_assert_cmpint(c->refcnt, ==, 2); 1304 1305 g_assert(QLIST_FIRST(&parent_b->children) == detach_by_parent_data.child_c); 1306 g_assert(QLIST_NEXT(detach_by_parent_data.child_c, next) == child_a); 1307 g_assert(QLIST_NEXT(child_a, next) == NULL); 1308 1309 g_assert_cmpint(parent_a->quiesce_counter, ==, 1); 1310 g_assert_cmpint(parent_b->quiesce_counter, ==, 3); 1311 g_assert_cmpint(a->quiesce_counter, ==, 1); 1312 g_assert_cmpint(b->quiesce_counter, ==, 1); 1313 g_assert_cmpint(c->quiesce_counter, ==, 1); 1314 1315 bdrv_drained_end(parent_b); 1316 bdrv_drained_end(a); 1317 bdrv_drained_end(b); 1318 bdrv_drained_end(c); 1319 1320 bdrv_unref(parent_b); 1321 blk_unref(blk); 1322 1323 g_assert_cmpint(a->refcnt, ==, 1); 1324 g_assert_cmpint(b->refcnt, ==, 1); 1325 g_assert_cmpint(c->refcnt, ==, 1); 1326 bdrv_unref(a); 1327 bdrv_unref(b); 1328 bdrv_unref(c); 1329 } 1330 1331 static void test_detach_by_parent_cb(void) 1332 { 1333 test_detach_indirect(true); 1334 } 1335 1336 static void test_detach_by_driver_cb(void) 1337 { 1338 test_detach_indirect(false); 1339 } 1340 1341 static void test_append_to_drained(void) 1342 { 1343 BlockBackend *blk; 1344 BlockDriverState *base, *overlay; 1345 BDRVTestState *base_s, *overlay_s; 1346 1347 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1348 base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort); 1349 base_s = base->opaque; 1350 blk_insert_bs(blk, base, &error_abort); 1351 1352 overlay = bdrv_new_open_driver(&bdrv_test, "overlay", BDRV_O_RDWR, 1353 &error_abort); 1354 overlay_s = overlay->opaque; 1355 1356 do_drain_begin(BDRV_DRAIN, base); 1357 g_assert_cmpint(base->quiesce_counter, ==, 1); 1358 g_assert_cmpint(base_s->drain_count, ==, 1); 1359 g_assert_cmpint(base->in_flight, ==, 0); 1360 1361 bdrv_append(overlay, base, &error_abort); 1362 g_assert_cmpint(base->in_flight, ==, 0); 1363 g_assert_cmpint(overlay->in_flight, ==, 0); 1364 1365 g_assert_cmpint(base->quiesce_counter, ==, 1); 1366 g_assert_cmpint(base_s->drain_count, ==, 1); 1367 g_assert_cmpint(overlay->quiesce_counter, ==, 1); 1368 g_assert_cmpint(overlay_s->drain_count, ==, 1); 1369 1370 do_drain_end(BDRV_DRAIN, base); 1371 1372 g_assert_cmpint(base->quiesce_counter, ==, 0); 1373 g_assert_cmpint(base_s->drain_count, ==, 0); 1374 g_assert_cmpint(overlay->quiesce_counter, ==, 0); 1375 g_assert_cmpint(overlay_s->drain_count, ==, 0); 1376 1377 bdrv_unref(overlay); 1378 bdrv_unref(base); 1379 blk_unref(blk); 1380 } 1381 1382 static void test_set_aio_context(void) 1383 { 1384 BlockDriverState *bs; 1385 IOThread *a = iothread_new(); 1386 IOThread *b = iothread_new(); 1387 AioContext *ctx_a = iothread_get_aio_context(a); 1388 AioContext *ctx_b = iothread_get_aio_context(b); 1389 1390 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 1391 &error_abort); 1392 1393 bdrv_drained_begin(bs); 1394 bdrv_try_change_aio_context(bs, ctx_a, NULL, &error_abort); 1395 1396 aio_context_acquire(ctx_a); 1397 bdrv_drained_end(bs); 1398 1399 bdrv_drained_begin(bs); 1400 bdrv_try_change_aio_context(bs, ctx_b, NULL, &error_abort); 1401 aio_context_release(ctx_a); 1402 aio_context_acquire(ctx_b); 1403 bdrv_try_change_aio_context(bs, qemu_get_aio_context(), NULL, &error_abort); 1404 aio_context_release(ctx_b); 1405 bdrv_drained_end(bs); 1406 1407 bdrv_unref(bs); 1408 iothread_join(a); 1409 iothread_join(b); 1410 } 1411 1412 1413 typedef struct TestDropBackingBlockJob { 1414 BlockJob common; 1415 bool should_complete; 1416 bool *did_complete; 1417 BlockDriverState *detach_also; 1418 BlockDriverState *bs; 1419 } TestDropBackingBlockJob; 1420 1421 static int coroutine_fn test_drop_backing_job_run(Job *job, Error **errp) 1422 { 1423 TestDropBackingBlockJob *s = 1424 container_of(job, TestDropBackingBlockJob, common.job); 1425 1426 while (!s->should_complete) { 1427 job_sleep_ns(job, 0); 1428 } 1429 1430 return 0; 1431 } 1432 1433 static void test_drop_backing_job_commit(Job *job) 1434 { 1435 TestDropBackingBlockJob *s = 1436 container_of(job, TestDropBackingBlockJob, common.job); 1437 1438 bdrv_set_backing_hd(s->bs, NULL, &error_abort); 1439 bdrv_set_backing_hd(s->detach_also, NULL, &error_abort); 1440 1441 *s->did_complete = true; 1442 } 1443 1444 static const BlockJobDriver test_drop_backing_job_driver = { 1445 .job_driver = { 1446 .instance_size = sizeof(TestDropBackingBlockJob), 1447 .free = block_job_free, 1448 .user_resume = block_job_user_resume, 1449 .run = test_drop_backing_job_run, 1450 .commit = test_drop_backing_job_commit, 1451 } 1452 }; 1453 1454 /** 1455 * Creates a child node with three parent nodes on it, and then runs a 1456 * block job on the final one, parent-node-2. 1457 * 1458 * The job is then asked to complete before a section where the child 1459 * is drained. 1460 * 1461 * Ending this section will undrain the child's parents, first 1462 * parent-node-2, then parent-node-1, then parent-node-0 -- the parent 1463 * list is in reverse order of how they were added. Ending the drain 1464 * on parent-node-2 will resume the job, thus completing it and 1465 * scheduling job_exit(). 1466 * 1467 * Ending the drain on parent-node-1 will poll the AioContext, which 1468 * lets job_exit() and thus test_drop_backing_job_commit() run. That 1469 * function first removes the child as parent-node-2's backing file. 1470 * 1471 * In old (and buggy) implementations, there are two problems with 1472 * that: 1473 * (A) bdrv_drain_invoke() polls for every node that leaves the 1474 * drained section. This means that job_exit() is scheduled 1475 * before the child has left the drained section. Its 1476 * quiesce_counter is therefore still 1 when it is removed from 1477 * parent-node-2. 1478 * 1479 * (B) bdrv_replace_child_noperm() calls drained_end() on the old 1480 * child's parents as many times as the child is quiesced. This 1481 * means it will call drained_end() on parent-node-2 once. 1482 * Because parent-node-2 is no longer quiesced at this point, this 1483 * will fail. 1484 * 1485 * bdrv_replace_child_noperm() therefore must call drained_end() on 1486 * the parent only if it really is still drained because the child is 1487 * drained. 1488 * 1489 * If removing child from parent-node-2 was successful (as it should 1490 * be), test_drop_backing_job_commit() will then also remove the child 1491 * from parent-node-0. 1492 * 1493 * With an old version of our drain infrastructure ((A) above), that 1494 * resulted in the following flow: 1495 * 1496 * 1. child attempts to leave its drained section. The call recurses 1497 * to its parents. 1498 * 1499 * 2. parent-node-2 leaves the drained section. Polling in 1500 * bdrv_drain_invoke() will schedule job_exit(). 1501 * 1502 * 3. parent-node-1 leaves the drained section. Polling in 1503 * bdrv_drain_invoke() will run job_exit(), thus disconnecting 1504 * parent-node-0 from the child node. 1505 * 1506 * 4. bdrv_parent_drained_end() uses a QLIST_FOREACH_SAFE() loop to 1507 * iterate over the parents. Thus, it now accesses the BdrvChild 1508 * object that used to connect parent-node-0 and the child node. 1509 * However, that object no longer exists, so it accesses a dangling 1510 * pointer. 1511 * 1512 * The solution is to only poll once when running a bdrv_drained_end() 1513 * operation, specifically at the end when all drained_end() 1514 * operations for all involved nodes have been scheduled. 1515 * Note that this also solves (A) above, thus hiding (B). 1516 */ 1517 static void test_blockjob_commit_by_drained_end(void) 1518 { 1519 BlockDriverState *bs_child, *bs_parents[3]; 1520 TestDropBackingBlockJob *job; 1521 bool job_has_completed = false; 1522 int i; 1523 1524 bs_child = bdrv_new_open_driver(&bdrv_test, "child-node", BDRV_O_RDWR, 1525 &error_abort); 1526 1527 for (i = 0; i < 3; i++) { 1528 char name[32]; 1529 snprintf(name, sizeof(name), "parent-node-%i", i); 1530 bs_parents[i] = bdrv_new_open_driver(&bdrv_test, name, BDRV_O_RDWR, 1531 &error_abort); 1532 bdrv_set_backing_hd(bs_parents[i], bs_child, &error_abort); 1533 } 1534 1535 job = block_job_create("job", &test_drop_backing_job_driver, NULL, 1536 bs_parents[2], 0, BLK_PERM_ALL, 0, 0, NULL, NULL, 1537 &error_abort); 1538 job->bs = bs_parents[2]; 1539 1540 job->detach_also = bs_parents[0]; 1541 job->did_complete = &job_has_completed; 1542 1543 job_start(&job->common.job); 1544 1545 job->should_complete = true; 1546 bdrv_drained_begin(bs_child); 1547 g_assert(!job_has_completed); 1548 bdrv_drained_end(bs_child); 1549 aio_poll(qemu_get_aio_context(), false); 1550 g_assert(job_has_completed); 1551 1552 bdrv_unref(bs_parents[0]); 1553 bdrv_unref(bs_parents[1]); 1554 bdrv_unref(bs_parents[2]); 1555 bdrv_unref(bs_child); 1556 } 1557 1558 1559 typedef struct TestSimpleBlockJob { 1560 BlockJob common; 1561 bool should_complete; 1562 bool *did_complete; 1563 } TestSimpleBlockJob; 1564 1565 static int coroutine_fn test_simple_job_run(Job *job, Error **errp) 1566 { 1567 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1568 1569 while (!s->should_complete) { 1570 job_sleep_ns(job, 0); 1571 } 1572 1573 return 0; 1574 } 1575 1576 static void test_simple_job_clean(Job *job) 1577 { 1578 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1579 *s->did_complete = true; 1580 } 1581 1582 static const BlockJobDriver test_simple_job_driver = { 1583 .job_driver = { 1584 .instance_size = sizeof(TestSimpleBlockJob), 1585 .free = block_job_free, 1586 .user_resume = block_job_user_resume, 1587 .run = test_simple_job_run, 1588 .clean = test_simple_job_clean, 1589 }, 1590 }; 1591 1592 static int drop_intermediate_poll_update_filename(BdrvChild *child, 1593 BlockDriverState *new_base, 1594 const char *filename, 1595 Error **errp) 1596 { 1597 /* 1598 * We are free to poll here, which may change the block graph, if 1599 * it is not drained. 1600 */ 1601 1602 /* If the job is not drained: Complete it, schedule job_exit() */ 1603 aio_poll(qemu_get_current_aio_context(), false); 1604 /* If the job is not drained: Run job_exit(), finish the job */ 1605 aio_poll(qemu_get_current_aio_context(), false); 1606 1607 return 0; 1608 } 1609 1610 /** 1611 * Test a poll in the midst of bdrv_drop_intermediate(). 1612 * 1613 * bdrv_drop_intermediate() calls BdrvChildClass.update_filename(), 1614 * which can yield or poll. This may lead to graph changes, unless 1615 * the whole subtree in question is drained. 1616 * 1617 * We test this on the following graph: 1618 * 1619 * Job 1620 * 1621 * | 1622 * job-node 1623 * | 1624 * v 1625 * 1626 * job-node 1627 * 1628 * | 1629 * backing 1630 * | 1631 * v 1632 * 1633 * node-2 --chain--> node-1 --chain--> node-0 1634 * 1635 * We drop node-1 with bdrv_drop_intermediate(top=node-1, base=node-0). 1636 * 1637 * This first updates node-2's backing filename by invoking 1638 * drop_intermediate_poll_update_filename(), which polls twice. This 1639 * causes the job to finish, which in turns causes the job-node to be 1640 * deleted. 1641 * 1642 * bdrv_drop_intermediate() uses a QLIST_FOREACH_SAFE() loop, so it 1643 * already has a pointer to the BdrvChild edge between job-node and 1644 * node-1. When it tries to handle that edge, we probably get a 1645 * segmentation fault because the object no longer exists. 1646 * 1647 * 1648 * The solution is for bdrv_drop_intermediate() to drain top's 1649 * subtree. This prevents graph changes from happening just because 1650 * BdrvChildClass.update_filename() yields or polls. Thus, the block 1651 * job is paused during that drained section and must finish before or 1652 * after. 1653 * 1654 * (In addition, bdrv_replace_child() must keep the job paused.) 1655 */ 1656 static void test_drop_intermediate_poll(void) 1657 { 1658 static BdrvChildClass chain_child_class; 1659 BlockDriverState *chain[3]; 1660 TestSimpleBlockJob *job; 1661 BlockDriverState *job_node; 1662 bool job_has_completed = false; 1663 int i; 1664 int ret; 1665 1666 chain_child_class = child_of_bds; 1667 chain_child_class.update_filename = drop_intermediate_poll_update_filename; 1668 1669 for (i = 0; i < 3; i++) { 1670 char name[32]; 1671 snprintf(name, 32, "node-%i", i); 1672 1673 chain[i] = bdrv_new_open_driver(&bdrv_test, name, 0, &error_abort); 1674 } 1675 1676 job_node = bdrv_new_open_driver(&bdrv_test, "job-node", BDRV_O_RDWR, 1677 &error_abort); 1678 bdrv_set_backing_hd(job_node, chain[1], &error_abort); 1679 1680 /* 1681 * Establish the chain last, so the chain links are the first 1682 * elements in the BDS.parents lists 1683 */ 1684 for (i = 0; i < 3; i++) { 1685 if (i) { 1686 /* Takes the reference to chain[i - 1] */ 1687 bdrv_attach_child(chain[i], chain[i - 1], "chain", 1688 &chain_child_class, BDRV_CHILD_COW, &error_abort); 1689 } 1690 } 1691 1692 job = block_job_create("job", &test_simple_job_driver, NULL, job_node, 1693 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort); 1694 1695 /* The job has a reference now */ 1696 bdrv_unref(job_node); 1697 1698 job->did_complete = &job_has_completed; 1699 1700 job_start(&job->common.job); 1701 job->should_complete = true; 1702 1703 g_assert(!job_has_completed); 1704 ret = bdrv_drop_intermediate(chain[1], chain[0], NULL); 1705 aio_poll(qemu_get_aio_context(), false); 1706 g_assert(ret == 0); 1707 g_assert(job_has_completed); 1708 1709 bdrv_unref(chain[2]); 1710 } 1711 1712 1713 typedef struct BDRVReplaceTestState { 1714 bool setup_completed; 1715 bool was_drained; 1716 bool was_undrained; 1717 bool has_read; 1718 1719 int drain_count; 1720 1721 bool yield_before_read; 1722 Coroutine *io_co; 1723 Coroutine *drain_co; 1724 } BDRVReplaceTestState; 1725 1726 static void bdrv_replace_test_close(BlockDriverState *bs) 1727 { 1728 } 1729 1730 /** 1731 * If @bs has a backing file: 1732 * Yield if .yield_before_read is true (and wait for drain_begin to 1733 * wake us up). 1734 * Forward the read to bs->backing. Set .has_read to true. 1735 * If drain_begin has woken us, wake it in turn. 1736 * 1737 * Otherwise: 1738 * Set .has_read to true and return success. 1739 */ 1740 static int coroutine_fn GRAPH_RDLOCK 1741 bdrv_replace_test_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 1742 QEMUIOVector *qiov, BdrvRequestFlags flags) 1743 { 1744 BDRVReplaceTestState *s = bs->opaque; 1745 1746 if (bs->backing) { 1747 int ret; 1748 1749 g_assert(!s->drain_count); 1750 1751 s->io_co = qemu_coroutine_self(); 1752 if (s->yield_before_read) { 1753 s->yield_before_read = false; 1754 qemu_coroutine_yield(); 1755 } 1756 s->io_co = NULL; 1757 1758 ret = bdrv_co_preadv(bs->backing, offset, bytes, qiov, 0); 1759 s->has_read = true; 1760 1761 /* Wake up drain_co if it runs */ 1762 if (s->drain_co) { 1763 aio_co_wake(s->drain_co); 1764 } 1765 1766 return ret; 1767 } 1768 1769 s->has_read = true; 1770 return 0; 1771 } 1772 1773 static void coroutine_fn bdrv_replace_test_drain_co(void *opaque) 1774 { 1775 BlockDriverState *bs = opaque; 1776 BDRVReplaceTestState *s = bs->opaque; 1777 1778 /* Keep waking io_co up until it is done */ 1779 while (s->io_co) { 1780 aio_co_wake(s->io_co); 1781 s->io_co = NULL; 1782 qemu_coroutine_yield(); 1783 } 1784 s->drain_co = NULL; 1785 bdrv_dec_in_flight(bs); 1786 } 1787 1788 /** 1789 * If .drain_count is 0, wake up .io_co if there is one; and set 1790 * .was_drained. 1791 * Increment .drain_count. 1792 */ 1793 static void bdrv_replace_test_drain_begin(BlockDriverState *bs) 1794 { 1795 BDRVReplaceTestState *s = bs->opaque; 1796 1797 if (!s->setup_completed) { 1798 return; 1799 } 1800 1801 if (!s->drain_count) { 1802 s->drain_co = qemu_coroutine_create(bdrv_replace_test_drain_co, bs); 1803 bdrv_inc_in_flight(bs); 1804 aio_co_enter(bdrv_get_aio_context(bs), s->drain_co); 1805 s->was_drained = true; 1806 } 1807 s->drain_count++; 1808 } 1809 1810 static void coroutine_fn bdrv_replace_test_read_entry(void *opaque) 1811 { 1812 BlockDriverState *bs = opaque; 1813 char data; 1814 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); 1815 int ret; 1816 1817 /* Queue a read request post-drain */ 1818 bdrv_graph_co_rdlock(); 1819 ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); 1820 bdrv_graph_co_rdunlock(); 1821 1822 g_assert(ret >= 0); 1823 bdrv_dec_in_flight(bs); 1824 } 1825 1826 /** 1827 * Reduce .drain_count, set .was_undrained once it reaches 0. 1828 * If .drain_count reaches 0 and the node has a backing file, issue a 1829 * read request. 1830 */ 1831 static void bdrv_replace_test_drain_end(BlockDriverState *bs) 1832 { 1833 BDRVReplaceTestState *s = bs->opaque; 1834 1835 if (!s->setup_completed) { 1836 return; 1837 } 1838 1839 g_assert(s->drain_count > 0); 1840 if (!--s->drain_count) { 1841 s->was_undrained = true; 1842 1843 if (bs->backing) { 1844 Coroutine *co = qemu_coroutine_create(bdrv_replace_test_read_entry, 1845 bs); 1846 bdrv_inc_in_flight(bs); 1847 aio_co_enter(bdrv_get_aio_context(bs), co); 1848 } 1849 } 1850 } 1851 1852 static BlockDriver bdrv_replace_test = { 1853 .format_name = "replace_test", 1854 .instance_size = sizeof(BDRVReplaceTestState), 1855 .supports_backing = true, 1856 1857 .bdrv_close = bdrv_replace_test_close, 1858 .bdrv_co_preadv = bdrv_replace_test_co_preadv, 1859 1860 .bdrv_drain_begin = bdrv_replace_test_drain_begin, 1861 .bdrv_drain_end = bdrv_replace_test_drain_end, 1862 1863 .bdrv_child_perm = bdrv_default_perms, 1864 }; 1865 1866 static void coroutine_fn test_replace_child_mid_drain_read_co(void *opaque) 1867 { 1868 int ret; 1869 char data; 1870 1871 ret = blk_co_pread(opaque, 0, 1, &data, 0); 1872 g_assert(ret >= 0); 1873 } 1874 1875 /** 1876 * We test two things: 1877 * (1) bdrv_replace_child_noperm() must not undrain the parent if both 1878 * children are drained. 1879 * (2) bdrv_replace_child_noperm() must never flush I/O requests to a 1880 * drained child. If the old child is drained, it must flush I/O 1881 * requests after the new one has been attached. If the new child 1882 * is drained, it must flush I/O requests before the old one is 1883 * detached. 1884 * 1885 * To do so, we create one parent node and two child nodes; then 1886 * attach one of the children (old_child_bs) to the parent, then 1887 * drain both old_child_bs and new_child_bs according to 1888 * old_drain_count and new_drain_count, respectively, and finally 1889 * we invoke bdrv_replace_node() to replace old_child_bs by 1890 * new_child_bs. 1891 * 1892 * The test block driver we use here (bdrv_replace_test) has a read 1893 * function that: 1894 * - For the parent node, can optionally yield, and then forwards the 1895 * read to bdrv_preadv(), 1896 * - For the child node, just returns immediately. 1897 * 1898 * If the read yields, the drain_begin function will wake it up. 1899 * 1900 * The drain_end function issues a read on the parent once it is fully 1901 * undrained (which simulates requests starting to come in again). 1902 */ 1903 static void do_test_replace_child_mid_drain(int old_drain_count, 1904 int new_drain_count) 1905 { 1906 BlockBackend *parent_blk; 1907 BlockDriverState *parent_bs; 1908 BlockDriverState *old_child_bs, *new_child_bs; 1909 BDRVReplaceTestState *parent_s; 1910 BDRVReplaceTestState *old_child_s, *new_child_s; 1911 Coroutine *io_co; 1912 int i; 1913 1914 parent_bs = bdrv_new_open_driver(&bdrv_replace_test, "parent", 0, 1915 &error_abort); 1916 parent_s = parent_bs->opaque; 1917 1918 parent_blk = blk_new(qemu_get_aio_context(), 1919 BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL); 1920 blk_insert_bs(parent_blk, parent_bs, &error_abort); 1921 1922 old_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "old-child", 0, 1923 &error_abort); 1924 new_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "new-child", 0, 1925 &error_abort); 1926 old_child_s = old_child_bs->opaque; 1927 new_child_s = new_child_bs->opaque; 1928 1929 /* So that we can read something */ 1930 parent_bs->total_sectors = 1; 1931 old_child_bs->total_sectors = 1; 1932 new_child_bs->total_sectors = 1; 1933 1934 bdrv_ref(old_child_bs); 1935 bdrv_attach_child(parent_bs, old_child_bs, "child", &child_of_bds, 1936 BDRV_CHILD_COW, &error_abort); 1937 parent_s->setup_completed = true; 1938 1939 for (i = 0; i < old_drain_count; i++) { 1940 bdrv_drained_begin(old_child_bs); 1941 } 1942 for (i = 0; i < new_drain_count; i++) { 1943 bdrv_drained_begin(new_child_bs); 1944 } 1945 1946 if (!old_drain_count) { 1947 /* 1948 * Start a read operation that will yield, so it will not 1949 * complete before the node is drained. 1950 */ 1951 parent_s->yield_before_read = true; 1952 io_co = qemu_coroutine_create(test_replace_child_mid_drain_read_co, 1953 parent_blk); 1954 qemu_coroutine_enter(io_co); 1955 } 1956 1957 /* If we have started a read operation, it should have yielded */ 1958 g_assert(!parent_s->has_read); 1959 1960 /* Reset drained status so we can see what bdrv_replace_node() does */ 1961 parent_s->was_drained = false; 1962 parent_s->was_undrained = false; 1963 1964 g_assert(parent_bs->quiesce_counter == old_drain_count); 1965 bdrv_replace_node(old_child_bs, new_child_bs, &error_abort); 1966 g_assert(parent_bs->quiesce_counter == new_drain_count); 1967 1968 if (!old_drain_count && !new_drain_count) { 1969 /* 1970 * From undrained to undrained drains and undrains the parent, 1971 * because bdrv_replace_node() contains a drained section for 1972 * @old_child_bs. 1973 */ 1974 g_assert(parent_s->was_drained && parent_s->was_undrained); 1975 } else if (!old_drain_count && new_drain_count) { 1976 /* 1977 * From undrained to drained should drain the parent and keep 1978 * it that way. 1979 */ 1980 g_assert(parent_s->was_drained && !parent_s->was_undrained); 1981 } else if (old_drain_count && !new_drain_count) { 1982 /* 1983 * From drained to undrained should undrain the parent and 1984 * keep it that way. 1985 */ 1986 g_assert(!parent_s->was_drained && parent_s->was_undrained); 1987 } else /* if (old_drain_count && new_drain_count) */ { 1988 /* 1989 * From drained to drained must not undrain the parent at any 1990 * point 1991 */ 1992 g_assert(!parent_s->was_drained && !parent_s->was_undrained); 1993 } 1994 1995 if (!old_drain_count || !new_drain_count) { 1996 /* 1997 * If !old_drain_count, we have started a read request before 1998 * bdrv_replace_node(). If !new_drain_count, the parent must 1999 * have been undrained at some point, and 2000 * bdrv_replace_test_co_drain_end() starts a read request 2001 * then. 2002 */ 2003 g_assert(parent_s->has_read); 2004 } else { 2005 /* 2006 * If the parent was never undrained, there is no way to start 2007 * a read request. 2008 */ 2009 g_assert(!parent_s->has_read); 2010 } 2011 2012 /* A drained child must have not received any request */ 2013 g_assert(!(old_drain_count && old_child_s->has_read)); 2014 g_assert(!(new_drain_count && new_child_s->has_read)); 2015 2016 for (i = 0; i < new_drain_count; i++) { 2017 bdrv_drained_end(new_child_bs); 2018 } 2019 for (i = 0; i < old_drain_count; i++) { 2020 bdrv_drained_end(old_child_bs); 2021 } 2022 2023 /* 2024 * By now, bdrv_replace_test_co_drain_end() must have been called 2025 * at some point while the new child was attached to the parent. 2026 */ 2027 g_assert(parent_s->has_read); 2028 g_assert(new_child_s->has_read); 2029 2030 blk_unref(parent_blk); 2031 bdrv_unref(parent_bs); 2032 bdrv_unref(old_child_bs); 2033 bdrv_unref(new_child_bs); 2034 } 2035 2036 static void test_replace_child_mid_drain(void) 2037 { 2038 int old_drain_count, new_drain_count; 2039 2040 for (old_drain_count = 0; old_drain_count < 2; old_drain_count++) { 2041 for (new_drain_count = 0; new_drain_count < 2; new_drain_count++) { 2042 do_test_replace_child_mid_drain(old_drain_count, new_drain_count); 2043 } 2044 } 2045 } 2046 2047 int main(int argc, char **argv) 2048 { 2049 int ret; 2050 2051 bdrv_init(); 2052 qemu_init_main_loop(&error_abort); 2053 2054 g_test_init(&argc, &argv, NULL); 2055 qemu_event_init(&done_event, false); 2056 2057 g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all); 2058 g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain); 2059 2060 g_test_add_func("/bdrv-drain/driver-cb/co/drain_all", 2061 test_drv_cb_co_drain_all); 2062 g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain); 2063 2064 g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all); 2065 g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain); 2066 2067 g_test_add_func("/bdrv-drain/quiesce/co/drain_all", 2068 test_quiesce_co_drain_all); 2069 g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain); 2070 2071 g_test_add_func("/bdrv-drain/nested", test_nested); 2072 2073 g_test_add_func("/bdrv-drain/graph-change/drain_all", 2074 test_graph_change_drain_all); 2075 2076 g_test_add_func("/bdrv-drain/iothread/drain_all", test_iothread_drain_all); 2077 g_test_add_func("/bdrv-drain/iothread/drain", test_iothread_drain); 2078 2079 g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all); 2080 g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain); 2081 2082 g_test_add_func("/bdrv-drain/blockjob/error/drain_all", 2083 test_blockjob_error_drain_all); 2084 g_test_add_func("/bdrv-drain/blockjob/error/drain", 2085 test_blockjob_error_drain); 2086 2087 g_test_add_func("/bdrv-drain/blockjob/iothread/drain_all", 2088 test_blockjob_iothread_drain_all); 2089 g_test_add_func("/bdrv-drain/blockjob/iothread/drain", 2090 test_blockjob_iothread_drain); 2091 2092 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_all", 2093 test_blockjob_iothread_error_drain_all); 2094 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain", 2095 test_blockjob_iothread_error_drain); 2096 2097 g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain); 2098 g_test_add_func("/bdrv-drain/detach/drain_all", test_detach_by_drain_all); 2099 g_test_add_func("/bdrv-drain/detach/drain", test_detach_by_drain); 2100 g_test_add_func("/bdrv-drain/detach/parent_cb", test_detach_by_parent_cb); 2101 g_test_add_func("/bdrv-drain/detach/driver_cb", test_detach_by_driver_cb); 2102 2103 g_test_add_func("/bdrv-drain/attach/drain", test_append_to_drained); 2104 2105 g_test_add_func("/bdrv-drain/set_aio_context", test_set_aio_context); 2106 2107 g_test_add_func("/bdrv-drain/blockjob/commit_by_drained_end", 2108 test_blockjob_commit_by_drained_end); 2109 2110 g_test_add_func("/bdrv-drain/bdrv_drop_intermediate/poll", 2111 test_drop_intermediate_poll); 2112 2113 g_test_add_func("/bdrv-drain/replace_child/mid-drain", 2114 test_replace_child_mid_drain); 2115 2116 ret = g_test_run(); 2117 qemu_event_destroy(&done_event); 2118 return ret; 2119 } 2120