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); 476 477 bdrv_unref(bs_b); 478 blk_unref(blk_b); 479 } 480 481 struct test_iothread_data { 482 BlockDriverState *bs; 483 enum drain_type drain_type; 484 int *aio_ret; 485 bool co_done; 486 }; 487 488 static void coroutine_fn test_iothread_drain_co_entry(void *opaque) 489 { 490 struct test_iothread_data *data = opaque; 491 492 do_drain_begin(data->drain_type, data->bs); 493 g_assert_cmpint(*data->aio_ret, ==, 0); 494 do_drain_end(data->drain_type, data->bs); 495 496 data->co_done = true; 497 aio_wait_kick(); 498 } 499 500 static void test_iothread_aio_cb(void *opaque, int ret) 501 { 502 int *aio_ret = opaque; 503 *aio_ret = ret; 504 qemu_event_set(&done_event); 505 } 506 507 static void test_iothread_main_thread_bh(void *opaque) 508 { 509 struct test_iothread_data *data = opaque; 510 511 /* Test that the AioContext is not yet locked in a random BH that is 512 * executed during drain, otherwise this would deadlock. */ 513 aio_context_acquire(bdrv_get_aio_context(data->bs)); 514 bdrv_flush(data->bs); 515 bdrv_dec_in_flight(data->bs); /* incremented by test_iothread_common() */ 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 Coroutine *co; 535 int aio_ret; 536 struct test_iothread_data data; 537 538 IOThread *a = iothread_new(); 539 IOThread *b = iothread_new(); 540 AioContext *ctx_a = iothread_get_aio_context(a); 541 AioContext *ctx_b = iothread_get_aio_context(b); 542 543 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 544 545 /* bdrv_drain_all() may only be called from the main loop thread */ 546 if (drain_type == BDRV_DRAIN_ALL && drain_thread != 0) { 547 goto out; 548 } 549 550 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 551 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 552 &error_abort); 553 s = bs->opaque; 554 blk_insert_bs(blk, bs, &error_abort); 555 blk_set_disable_request_queuing(blk, true); 556 557 blk_set_aio_context(blk, ctx_a, &error_abort); 558 aio_context_acquire(ctx_a); 559 560 s->bh_indirection_ctx = ctx_b; 561 562 aio_ret = -EINPROGRESS; 563 qemu_event_reset(&done_event); 564 565 if (drain_thread == 0) { 566 acb = blk_aio_preadv(blk, 0, &qiov, 0, test_iothread_aio_cb, &aio_ret); 567 } else { 568 acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); 569 } 570 g_assert(acb != NULL); 571 g_assert_cmpint(aio_ret, ==, -EINPROGRESS); 572 573 aio_context_release(ctx_a); 574 575 data = (struct test_iothread_data) { 576 .bs = bs, 577 .drain_type = drain_type, 578 .aio_ret = &aio_ret, 579 }; 580 581 switch (drain_thread) { 582 case 0: 583 if (drain_type != BDRV_DRAIN_ALL) { 584 aio_context_acquire(ctx_a); 585 } 586 587 /* 588 * Increment in_flight so that do_drain_begin() waits for 589 * test_iothread_main_thread_bh(). This prevents the race between 590 * test_iothread_main_thread_bh() in IOThread a and do_drain_begin() in 591 * this thread. test_iothread_main_thread_bh() decrements in_flight. 592 */ 593 bdrv_inc_in_flight(bs); 594 aio_bh_schedule_oneshot(ctx_a, test_iothread_main_thread_bh, &data); 595 596 /* The request is running on the IOThread a. Draining its block device 597 * will make sure that it has completed as far as the BDS is concerned, 598 * but the drain in this thread can continue immediately after 599 * bdrv_dec_in_flight() and aio_ret might be assigned only slightly 600 * later. */ 601 do_drain_begin(drain_type, bs); 602 g_assert_cmpint(bs->in_flight, ==, 0); 603 604 if (drain_type != BDRV_DRAIN_ALL) { 605 aio_context_release(ctx_a); 606 } 607 qemu_event_wait(&done_event); 608 if (drain_type != BDRV_DRAIN_ALL) { 609 aio_context_acquire(ctx_a); 610 } 611 612 g_assert_cmpint(aio_ret, ==, 0); 613 do_drain_end(drain_type, bs); 614 615 if (drain_type != BDRV_DRAIN_ALL) { 616 aio_context_release(ctx_a); 617 } 618 break; 619 case 1: 620 co = qemu_coroutine_create(test_iothread_drain_co_entry, &data); 621 aio_co_enter(ctx_a, co); 622 AIO_WAIT_WHILE_UNLOCKED(NULL, !data.co_done); 623 break; 624 default: 625 g_assert_not_reached(); 626 } 627 628 aio_context_acquire(ctx_a); 629 blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort); 630 aio_context_release(ctx_a); 631 632 bdrv_unref(bs); 633 blk_unref(blk); 634 635 out: 636 iothread_join(a); 637 iothread_join(b); 638 } 639 640 static void test_iothread_drain_all(void) 641 { 642 test_iothread_common(BDRV_DRAIN_ALL, 0); 643 test_iothread_common(BDRV_DRAIN_ALL, 1); 644 } 645 646 static void test_iothread_drain(void) 647 { 648 test_iothread_common(BDRV_DRAIN, 0); 649 test_iothread_common(BDRV_DRAIN, 1); 650 } 651 652 653 typedef struct TestBlockJob { 654 BlockJob common; 655 BlockDriverState *bs; 656 int run_ret; 657 int prepare_ret; 658 bool running; 659 bool should_complete; 660 } TestBlockJob; 661 662 static int test_job_prepare(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 return s->prepare_ret; 669 } 670 671 static void test_job_commit(Job *job) 672 { 673 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 674 675 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 676 bdrv_flush(s->bs); 677 } 678 679 static void test_job_abort(Job *job) 680 { 681 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 682 683 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 684 bdrv_flush(s->bs); 685 } 686 687 static int coroutine_fn test_job_run(Job *job, Error **errp) 688 { 689 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 690 691 /* We are running the actual job code past the pause point in 692 * job_co_entry(). */ 693 s->running = true; 694 695 job_transition_to_ready(&s->common.job); 696 while (!s->should_complete) { 697 /* Avoid job_sleep_ns() because it marks the job as !busy. We want to 698 * emulate some actual activity (probably some I/O) here so that drain 699 * has to wait for this activity to stop. */ 700 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); 701 702 job_pause_point(&s->common.job); 703 } 704 705 return s->run_ret; 706 } 707 708 static void test_job_complete(Job *job, Error **errp) 709 { 710 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 711 s->should_complete = true; 712 } 713 714 BlockJobDriver test_job_driver = { 715 .job_driver = { 716 .instance_size = sizeof(TestBlockJob), 717 .free = block_job_free, 718 .user_resume = block_job_user_resume, 719 .run = test_job_run, 720 .complete = test_job_complete, 721 .prepare = test_job_prepare, 722 .commit = test_job_commit, 723 .abort = test_job_abort, 724 }, 725 }; 726 727 enum test_job_result { 728 TEST_JOB_SUCCESS, 729 TEST_JOB_FAIL_RUN, 730 TEST_JOB_FAIL_PREPARE, 731 }; 732 733 enum test_job_drain_node { 734 TEST_JOB_DRAIN_SRC, 735 TEST_JOB_DRAIN_SRC_CHILD, 736 }; 737 738 static void test_blockjob_common_drain_node(enum drain_type drain_type, 739 bool use_iothread, 740 enum test_job_result result, 741 enum test_job_drain_node drain_node) 742 { 743 BlockBackend *blk_src, *blk_target; 744 BlockDriverState *src, *src_backing, *src_overlay, *target, *drain_bs; 745 BlockJob *job; 746 TestBlockJob *tjob; 747 IOThread *iothread = NULL; 748 AioContext *ctx; 749 int ret; 750 751 src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR, 752 &error_abort); 753 src_backing = bdrv_new_open_driver(&bdrv_test, "source-backing", 754 BDRV_O_RDWR, &error_abort); 755 src_overlay = bdrv_new_open_driver(&bdrv_test, "source-overlay", 756 BDRV_O_RDWR, &error_abort); 757 758 bdrv_set_backing_hd(src_overlay, src, &error_abort); 759 bdrv_unref(src); 760 bdrv_set_backing_hd(src, src_backing, &error_abort); 761 bdrv_unref(src_backing); 762 763 blk_src = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 764 blk_insert_bs(blk_src, src_overlay, &error_abort); 765 766 switch (drain_node) { 767 case TEST_JOB_DRAIN_SRC: 768 drain_bs = src; 769 break; 770 case TEST_JOB_DRAIN_SRC_CHILD: 771 drain_bs = src_backing; 772 break; 773 default: 774 g_assert_not_reached(); 775 } 776 777 if (use_iothread) { 778 iothread = iothread_new(); 779 ctx = iothread_get_aio_context(iothread); 780 blk_set_aio_context(blk_src, ctx, &error_abort); 781 } else { 782 ctx = qemu_get_aio_context(); 783 } 784 785 target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR, 786 &error_abort); 787 blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 788 blk_insert_bs(blk_target, target, &error_abort); 789 blk_set_allow_aio_context_change(blk_target, true); 790 791 aio_context_acquire(ctx); 792 tjob = block_job_create("job0", &test_job_driver, NULL, src, 793 0, BLK_PERM_ALL, 794 0, 0, NULL, NULL, &error_abort); 795 tjob->bs = src; 796 job = &tjob->common; 797 block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort); 798 799 switch (result) { 800 case TEST_JOB_SUCCESS: 801 break; 802 case TEST_JOB_FAIL_RUN: 803 tjob->run_ret = -EIO; 804 break; 805 case TEST_JOB_FAIL_PREPARE: 806 tjob->prepare_ret = -EIO; 807 break; 808 } 809 aio_context_release(ctx); 810 811 job_start(&job->job); 812 813 if (use_iothread) { 814 /* job_co_entry() is run in the I/O thread, wait for the actual job 815 * code to start (we don't want to catch the job in the pause point in 816 * job_co_entry(). */ 817 while (!tjob->running) { 818 aio_poll(qemu_get_aio_context(), false); 819 } 820 } 821 822 WITH_JOB_LOCK_GUARD() { 823 g_assert_cmpint(job->job.pause_count, ==, 0); 824 g_assert_false(job->job.paused); 825 g_assert_true(tjob->running); 826 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 827 } 828 829 do_drain_begin_unlocked(drain_type, drain_bs); 830 831 WITH_JOB_LOCK_GUARD() { 832 if (drain_type == BDRV_DRAIN_ALL) { 833 /* bdrv_drain_all() drains both src and target */ 834 g_assert_cmpint(job->job.pause_count, ==, 2); 835 } else { 836 g_assert_cmpint(job->job.pause_count, ==, 1); 837 } 838 g_assert_true(job->job.paused); 839 g_assert_false(job->job.busy); /* The job is paused */ 840 } 841 842 do_drain_end_unlocked(drain_type, drain_bs); 843 844 if (use_iothread) { 845 /* 846 * Here we are waiting for the paused status to change, 847 * so don't bother protecting the read every time. 848 * 849 * paused is reset in the I/O thread, wait for it 850 */ 851 while (job->job.paused) { 852 aio_poll(qemu_get_aio_context(), false); 853 } 854 } 855 856 WITH_JOB_LOCK_GUARD() { 857 g_assert_cmpint(job->job.pause_count, ==, 0); 858 g_assert_false(job->job.paused); 859 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 860 } 861 862 do_drain_begin_unlocked(drain_type, target); 863 864 WITH_JOB_LOCK_GUARD() { 865 if (drain_type == BDRV_DRAIN_ALL) { 866 /* bdrv_drain_all() drains both src and target */ 867 g_assert_cmpint(job->job.pause_count, ==, 2); 868 } else { 869 g_assert_cmpint(job->job.pause_count, ==, 1); 870 } 871 g_assert_true(job->job.paused); 872 g_assert_false(job->job.busy); /* The job is paused */ 873 } 874 875 do_drain_end_unlocked(drain_type, target); 876 877 if (use_iothread) { 878 /* 879 * Here we are waiting for the paused status to change, 880 * so don't bother protecting the read every time. 881 * 882 * paused is reset in the I/O thread, wait for it 883 */ 884 while (job->job.paused) { 885 aio_poll(qemu_get_aio_context(), false); 886 } 887 } 888 889 WITH_JOB_LOCK_GUARD() { 890 g_assert_cmpint(job->job.pause_count, ==, 0); 891 g_assert_false(job->job.paused); 892 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 893 } 894 895 WITH_JOB_LOCK_GUARD() { 896 ret = job_complete_sync_locked(&job->job, &error_abort); 897 } 898 g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO)); 899 900 aio_context_acquire(ctx); 901 if (use_iothread) { 902 blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort); 903 assert(blk_get_aio_context(blk_target) == qemu_get_aio_context()); 904 } 905 aio_context_release(ctx); 906 907 blk_unref(blk_src); 908 blk_unref(blk_target); 909 bdrv_unref(src_overlay); 910 bdrv_unref(target); 911 912 if (iothread) { 913 iothread_join(iothread); 914 } 915 } 916 917 static void test_blockjob_common(enum drain_type drain_type, bool use_iothread, 918 enum test_job_result result) 919 { 920 test_blockjob_common_drain_node(drain_type, use_iothread, result, 921 TEST_JOB_DRAIN_SRC); 922 test_blockjob_common_drain_node(drain_type, use_iothread, result, 923 TEST_JOB_DRAIN_SRC_CHILD); 924 } 925 926 static void test_blockjob_drain_all(void) 927 { 928 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS); 929 } 930 931 static void test_blockjob_drain(void) 932 { 933 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_SUCCESS); 934 } 935 936 static void test_blockjob_error_drain_all(void) 937 { 938 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_RUN); 939 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_PREPARE); 940 } 941 942 static void test_blockjob_error_drain(void) 943 { 944 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_RUN); 945 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_PREPARE); 946 } 947 948 static void test_blockjob_iothread_drain_all(void) 949 { 950 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_SUCCESS); 951 } 952 953 static void test_blockjob_iothread_drain(void) 954 { 955 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_SUCCESS); 956 } 957 958 static void test_blockjob_iothread_error_drain_all(void) 959 { 960 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_RUN); 961 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_PREPARE); 962 } 963 964 static void test_blockjob_iothread_error_drain(void) 965 { 966 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_RUN); 967 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_PREPARE); 968 } 969 970 971 typedef struct BDRVTestTopState { 972 BdrvChild *wait_child; 973 } BDRVTestTopState; 974 975 static void bdrv_test_top_close(BlockDriverState *bs) 976 { 977 BdrvChild *c, *next_c; 978 979 bdrv_graph_wrlock(NULL); 980 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 981 bdrv_unref_child(bs, c); 982 } 983 bdrv_graph_wrunlock(); 984 } 985 986 static int coroutine_fn GRAPH_RDLOCK 987 bdrv_test_top_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 988 QEMUIOVector *qiov, BdrvRequestFlags flags) 989 { 990 BDRVTestTopState *tts = bs->opaque; 991 return bdrv_co_preadv(tts->wait_child, offset, bytes, qiov, flags); 992 } 993 994 static BlockDriver bdrv_test_top_driver = { 995 .format_name = "test_top_driver", 996 .instance_size = sizeof(BDRVTestTopState), 997 998 .bdrv_close = bdrv_test_top_close, 999 .bdrv_co_preadv = bdrv_test_top_co_preadv, 1000 1001 .bdrv_child_perm = bdrv_default_perms, 1002 }; 1003 1004 typedef struct TestCoDeleteByDrainData { 1005 BlockBackend *blk; 1006 bool detach_instead_of_delete; 1007 bool done; 1008 } TestCoDeleteByDrainData; 1009 1010 static void coroutine_fn test_co_delete_by_drain(void *opaque) 1011 { 1012 TestCoDeleteByDrainData *dbdd = opaque; 1013 BlockBackend *blk = dbdd->blk; 1014 BlockDriverState *bs = blk_bs(blk); 1015 BDRVTestTopState *tts = bs->opaque; 1016 void *buffer = g_malloc(65536); 1017 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buffer, 65536); 1018 1019 /* Pretend some internal write operation from parent to child. 1020 * Important: We have to read from the child, not from the parent! 1021 * Draining works by first propagating it all up the tree to the 1022 * root and then waiting for drainage from root to the leaves 1023 * (protocol nodes). If we have a request waiting on the root, 1024 * everything will be drained before we go back down the tree, but 1025 * we do not want that. We want to be in the middle of draining 1026 * when this following requests returns. */ 1027 bdrv_graph_co_rdlock(); 1028 bdrv_co_preadv(tts->wait_child, 0, 65536, &qiov, 0); 1029 bdrv_graph_co_rdunlock(); 1030 1031 g_assert_cmpint(bs->refcnt, ==, 1); 1032 1033 if (!dbdd->detach_instead_of_delete) { 1034 blk_co_unref(blk); 1035 } else { 1036 BdrvChild *c, *next_c; 1037 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 1038 bdrv_co_unref_child(bs, c); 1039 } 1040 } 1041 1042 dbdd->done = true; 1043 g_free(buffer); 1044 } 1045 1046 /** 1047 * Test what happens when some BDS has some children, you drain one of 1048 * them and this results in the BDS being deleted. 1049 * 1050 * If @detach_instead_of_delete is set, the BDS is not going to be 1051 * deleted but will only detach all of its children. 1052 */ 1053 static void do_test_delete_by_drain(bool detach_instead_of_delete, 1054 enum drain_type drain_type) 1055 { 1056 BlockBackend *blk; 1057 BlockDriverState *bs, *child_bs, *null_bs; 1058 BDRVTestTopState *tts; 1059 TestCoDeleteByDrainData dbdd; 1060 Coroutine *co; 1061 1062 bs = bdrv_new_open_driver(&bdrv_test_top_driver, "top", BDRV_O_RDWR, 1063 &error_abort); 1064 bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1065 tts = bs->opaque; 1066 1067 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1068 &error_abort); 1069 bdrv_graph_wrlock(NULL); 1070 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, 1071 BDRV_CHILD_DATA, &error_abort); 1072 bdrv_graph_wrunlock(); 1073 1074 /* This child will be the one to pass to requests through to, and 1075 * it will stall until a drain occurs */ 1076 child_bs = bdrv_new_open_driver(&bdrv_test, "child", BDRV_O_RDWR, 1077 &error_abort); 1078 child_bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1079 /* Takes our reference to child_bs */ 1080 bdrv_graph_wrlock(NULL); 1081 tts->wait_child = bdrv_attach_child(bs, child_bs, "wait-child", 1082 &child_of_bds, 1083 BDRV_CHILD_DATA | BDRV_CHILD_PRIMARY, 1084 &error_abort); 1085 bdrv_graph_wrunlock(); 1086 1087 /* This child is just there to be deleted 1088 * (for detach_instead_of_delete == true) */ 1089 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1090 &error_abort); 1091 bdrv_graph_wrlock(NULL); 1092 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, BDRV_CHILD_DATA, 1093 &error_abort); 1094 bdrv_graph_wrunlock(); 1095 1096 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1097 blk_insert_bs(blk, bs, &error_abort); 1098 1099 /* Referenced by blk now */ 1100 bdrv_unref(bs); 1101 1102 g_assert_cmpint(bs->refcnt, ==, 1); 1103 g_assert_cmpint(child_bs->refcnt, ==, 1); 1104 g_assert_cmpint(null_bs->refcnt, ==, 1); 1105 1106 1107 dbdd = (TestCoDeleteByDrainData){ 1108 .blk = blk, 1109 .detach_instead_of_delete = detach_instead_of_delete, 1110 .done = false, 1111 }; 1112 co = qemu_coroutine_create(test_co_delete_by_drain, &dbdd); 1113 qemu_coroutine_enter(co); 1114 1115 /* Drain the child while the read operation is still pending. 1116 * This should result in the operation finishing and 1117 * test_co_delete_by_drain() resuming. Thus, @bs will be deleted 1118 * and the coroutine will exit while this drain operation is still 1119 * in progress. */ 1120 switch (drain_type) { 1121 case BDRV_DRAIN: 1122 bdrv_ref(child_bs); 1123 bdrv_drain(child_bs); 1124 bdrv_unref(child_bs); 1125 break; 1126 case BDRV_DRAIN_ALL: 1127 bdrv_drain_all_begin(); 1128 bdrv_drain_all_end(); 1129 break; 1130 default: 1131 g_assert_not_reached(); 1132 } 1133 1134 while (!dbdd.done) { 1135 aio_poll(qemu_get_aio_context(), true); 1136 } 1137 1138 if (detach_instead_of_delete) { 1139 /* Here, the reference has not passed over to the coroutine, 1140 * so we have to delete the BB ourselves */ 1141 blk_unref(blk); 1142 } 1143 } 1144 1145 static void test_delete_by_drain(void) 1146 { 1147 do_test_delete_by_drain(false, BDRV_DRAIN); 1148 } 1149 1150 static void test_detach_by_drain_all(void) 1151 { 1152 do_test_delete_by_drain(true, BDRV_DRAIN_ALL); 1153 } 1154 1155 static void test_detach_by_drain(void) 1156 { 1157 do_test_delete_by_drain(true, BDRV_DRAIN); 1158 } 1159 1160 1161 struct detach_by_parent_data { 1162 BlockDriverState *parent_b; 1163 BdrvChild *child_b; 1164 BlockDriverState *c; 1165 BdrvChild *child_c; 1166 bool by_parent_cb; 1167 bool detach_on_drain; 1168 }; 1169 static struct detach_by_parent_data detach_by_parent_data; 1170 1171 static void detach_indirect_bh(void *opaque) 1172 { 1173 struct detach_by_parent_data *data = opaque; 1174 1175 bdrv_dec_in_flight(data->child_b->bs); 1176 1177 bdrv_graph_wrlock(NULL); 1178 bdrv_unref_child(data->parent_b, data->child_b); 1179 1180 bdrv_ref(data->c); 1181 data->child_c = bdrv_attach_child(data->parent_b, data->c, "PB-C", 1182 &child_of_bds, BDRV_CHILD_DATA, 1183 &error_abort); 1184 bdrv_graph_wrunlock(); 1185 } 1186 1187 static void detach_by_parent_aio_cb(void *opaque, int ret) 1188 { 1189 struct detach_by_parent_data *data = &detach_by_parent_data; 1190 1191 g_assert_cmpint(ret, ==, 0); 1192 if (data->by_parent_cb) { 1193 bdrv_inc_in_flight(data->child_b->bs); 1194 detach_indirect_bh(data); 1195 } 1196 } 1197 1198 static void detach_by_driver_cb_drained_begin(BdrvChild *child) 1199 { 1200 struct detach_by_parent_data *data = &detach_by_parent_data; 1201 1202 if (!data->detach_on_drain) { 1203 return; 1204 } 1205 data->detach_on_drain = false; 1206 1207 bdrv_inc_in_flight(data->child_b->bs); 1208 aio_bh_schedule_oneshot(qemu_get_current_aio_context(), 1209 detach_indirect_bh, &detach_by_parent_data); 1210 child_of_bds.drained_begin(child); 1211 } 1212 1213 static BdrvChildClass detach_by_driver_cb_class; 1214 1215 /* 1216 * Initial graph: 1217 * 1218 * PA PB 1219 * \ / \ 1220 * A B C 1221 * 1222 * by_parent_cb == true: Test that parent callbacks don't poll 1223 * 1224 * PA has a pending write request whose callback changes the child nodes of 1225 * PB: It removes B and adds C instead. The subtree of PB is drained, which 1226 * will indirectly drain the write request, too. 1227 * 1228 * by_parent_cb == false: Test that bdrv_drain_invoke() doesn't poll 1229 * 1230 * PA's BdrvChildClass has a .drained_begin callback that schedules a BH 1231 * that does the same graph change. If bdrv_drain_invoke() calls it, the 1232 * state is messed up, but if it is only polled in the single 1233 * BDRV_POLL_WHILE() at the end of the drain, this should work fine. 1234 */ 1235 static void test_detach_indirect(bool by_parent_cb) 1236 { 1237 BlockBackend *blk; 1238 BlockDriverState *parent_a, *parent_b, *a, *b, *c; 1239 BdrvChild *child_a, *child_b; 1240 BlockAIOCB *acb; 1241 1242 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 1243 1244 if (!by_parent_cb) { 1245 detach_by_driver_cb_class = child_of_bds; 1246 detach_by_driver_cb_class.drained_begin = 1247 detach_by_driver_cb_drained_begin; 1248 detach_by_driver_cb_class.drained_end = NULL; 1249 detach_by_driver_cb_class.drained_poll = NULL; 1250 } 1251 1252 detach_by_parent_data = (struct detach_by_parent_data) { 1253 .detach_on_drain = false, 1254 }; 1255 1256 /* Create all involved nodes */ 1257 parent_a = bdrv_new_open_driver(&bdrv_test, "parent-a", BDRV_O_RDWR, 1258 &error_abort); 1259 parent_b = bdrv_new_open_driver(&bdrv_test, "parent-b", 0, 1260 &error_abort); 1261 1262 a = bdrv_new_open_driver(&bdrv_test, "a", BDRV_O_RDWR, &error_abort); 1263 b = bdrv_new_open_driver(&bdrv_test, "b", BDRV_O_RDWR, &error_abort); 1264 c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort); 1265 1266 /* blk is a BB for parent-a */ 1267 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1268 blk_insert_bs(blk, parent_a, &error_abort); 1269 bdrv_unref(parent_a); 1270 1271 /* If we want to get bdrv_drain_invoke() to call aio_poll(), the driver 1272 * callback must not return immediately. */ 1273 if (!by_parent_cb) { 1274 BDRVTestState *s = parent_a->opaque; 1275 s->sleep_in_drain_begin = true; 1276 } 1277 1278 /* Set child relationships */ 1279 bdrv_ref(b); 1280 bdrv_ref(a); 1281 bdrv_graph_wrlock(NULL); 1282 child_b = bdrv_attach_child(parent_b, b, "PB-B", &child_of_bds, 1283 BDRV_CHILD_DATA, &error_abort); 1284 child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_of_bds, 1285 BDRV_CHILD_COW, &error_abort); 1286 1287 bdrv_ref(a); 1288 bdrv_attach_child(parent_a, a, "PA-A", 1289 by_parent_cb ? &child_of_bds : &detach_by_driver_cb_class, 1290 BDRV_CHILD_DATA, &error_abort); 1291 bdrv_graph_wrunlock(); 1292 1293 g_assert_cmpint(parent_a->refcnt, ==, 1); 1294 g_assert_cmpint(parent_b->refcnt, ==, 1); 1295 g_assert_cmpint(a->refcnt, ==, 3); 1296 g_assert_cmpint(b->refcnt, ==, 2); 1297 g_assert_cmpint(c->refcnt, ==, 1); 1298 1299 g_assert(QLIST_FIRST(&parent_b->children) == child_a); 1300 g_assert(QLIST_NEXT(child_a, next) == child_b); 1301 g_assert(QLIST_NEXT(child_b, next) == NULL); 1302 1303 /* Start the evil write request */ 1304 detach_by_parent_data = (struct detach_by_parent_data) { 1305 .parent_b = parent_b, 1306 .child_b = child_b, 1307 .c = c, 1308 .by_parent_cb = by_parent_cb, 1309 .detach_on_drain = true, 1310 }; 1311 acb = blk_aio_preadv(blk, 0, &qiov, 0, detach_by_parent_aio_cb, NULL); 1312 g_assert(acb != NULL); 1313 1314 /* Drain and check the expected result */ 1315 bdrv_drained_begin(parent_b); 1316 bdrv_drained_begin(a); 1317 bdrv_drained_begin(b); 1318 bdrv_drained_begin(c); 1319 1320 g_assert(detach_by_parent_data.child_c != NULL); 1321 1322 g_assert_cmpint(parent_a->refcnt, ==, 1); 1323 g_assert_cmpint(parent_b->refcnt, ==, 1); 1324 g_assert_cmpint(a->refcnt, ==, 3); 1325 g_assert_cmpint(b->refcnt, ==, 1); 1326 g_assert_cmpint(c->refcnt, ==, 2); 1327 1328 g_assert(QLIST_FIRST(&parent_b->children) == detach_by_parent_data.child_c); 1329 g_assert(QLIST_NEXT(detach_by_parent_data.child_c, next) == child_a); 1330 g_assert(QLIST_NEXT(child_a, next) == NULL); 1331 1332 g_assert_cmpint(parent_a->quiesce_counter, ==, 1); 1333 g_assert_cmpint(parent_b->quiesce_counter, ==, 3); 1334 g_assert_cmpint(a->quiesce_counter, ==, 1); 1335 g_assert_cmpint(b->quiesce_counter, ==, 1); 1336 g_assert_cmpint(c->quiesce_counter, ==, 1); 1337 1338 bdrv_drained_end(parent_b); 1339 bdrv_drained_end(a); 1340 bdrv_drained_end(b); 1341 bdrv_drained_end(c); 1342 1343 bdrv_unref(parent_b); 1344 blk_unref(blk); 1345 1346 g_assert_cmpint(a->refcnt, ==, 1); 1347 g_assert_cmpint(b->refcnt, ==, 1); 1348 g_assert_cmpint(c->refcnt, ==, 1); 1349 bdrv_unref(a); 1350 bdrv_unref(b); 1351 bdrv_unref(c); 1352 } 1353 1354 static void test_detach_by_parent_cb(void) 1355 { 1356 test_detach_indirect(true); 1357 } 1358 1359 static void test_detach_by_driver_cb(void) 1360 { 1361 test_detach_indirect(false); 1362 } 1363 1364 static void test_append_to_drained(void) 1365 { 1366 BlockBackend *blk; 1367 BlockDriverState *base, *overlay; 1368 BDRVTestState *base_s, *overlay_s; 1369 1370 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1371 base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort); 1372 base_s = base->opaque; 1373 blk_insert_bs(blk, base, &error_abort); 1374 1375 overlay = bdrv_new_open_driver(&bdrv_test, "overlay", BDRV_O_RDWR, 1376 &error_abort); 1377 overlay_s = overlay->opaque; 1378 1379 do_drain_begin(BDRV_DRAIN, base); 1380 g_assert_cmpint(base->quiesce_counter, ==, 1); 1381 g_assert_cmpint(base_s->drain_count, ==, 1); 1382 g_assert_cmpint(base->in_flight, ==, 0); 1383 1384 aio_context_acquire(qemu_get_aio_context()); 1385 bdrv_append(overlay, base, &error_abort); 1386 aio_context_release(qemu_get_aio_context()); 1387 1388 g_assert_cmpint(base->in_flight, ==, 0); 1389 g_assert_cmpint(overlay->in_flight, ==, 0); 1390 1391 g_assert_cmpint(base->quiesce_counter, ==, 1); 1392 g_assert_cmpint(base_s->drain_count, ==, 1); 1393 g_assert_cmpint(overlay->quiesce_counter, ==, 1); 1394 g_assert_cmpint(overlay_s->drain_count, ==, 1); 1395 1396 do_drain_end(BDRV_DRAIN, base); 1397 1398 g_assert_cmpint(base->quiesce_counter, ==, 0); 1399 g_assert_cmpint(base_s->drain_count, ==, 0); 1400 g_assert_cmpint(overlay->quiesce_counter, ==, 0); 1401 g_assert_cmpint(overlay_s->drain_count, ==, 0); 1402 1403 bdrv_unref(overlay); 1404 bdrv_unref(base); 1405 blk_unref(blk); 1406 } 1407 1408 static void test_set_aio_context(void) 1409 { 1410 BlockDriverState *bs; 1411 IOThread *a = iothread_new(); 1412 IOThread *b = iothread_new(); 1413 AioContext *ctx_a = iothread_get_aio_context(a); 1414 AioContext *ctx_b = iothread_get_aio_context(b); 1415 1416 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 1417 &error_abort); 1418 1419 bdrv_drained_begin(bs); 1420 bdrv_try_change_aio_context(bs, ctx_a, NULL, &error_abort); 1421 1422 aio_context_acquire(ctx_a); 1423 bdrv_drained_end(bs); 1424 1425 bdrv_drained_begin(bs); 1426 bdrv_try_change_aio_context(bs, ctx_b, NULL, &error_abort); 1427 aio_context_release(ctx_a); 1428 aio_context_acquire(ctx_b); 1429 bdrv_try_change_aio_context(bs, qemu_get_aio_context(), NULL, &error_abort); 1430 aio_context_release(ctx_b); 1431 bdrv_drained_end(bs); 1432 1433 bdrv_unref(bs); 1434 iothread_join(a); 1435 iothread_join(b); 1436 } 1437 1438 1439 typedef struct TestDropBackingBlockJob { 1440 BlockJob common; 1441 bool should_complete; 1442 bool *did_complete; 1443 BlockDriverState *detach_also; 1444 BlockDriverState *bs; 1445 } TestDropBackingBlockJob; 1446 1447 static int coroutine_fn test_drop_backing_job_run(Job *job, Error **errp) 1448 { 1449 TestDropBackingBlockJob *s = 1450 container_of(job, TestDropBackingBlockJob, common.job); 1451 1452 while (!s->should_complete) { 1453 job_sleep_ns(job, 0); 1454 } 1455 1456 return 0; 1457 } 1458 1459 static void test_drop_backing_job_commit(Job *job) 1460 { 1461 TestDropBackingBlockJob *s = 1462 container_of(job, TestDropBackingBlockJob, common.job); 1463 1464 bdrv_set_backing_hd(s->bs, NULL, &error_abort); 1465 bdrv_set_backing_hd(s->detach_also, NULL, &error_abort); 1466 1467 *s->did_complete = true; 1468 } 1469 1470 static const BlockJobDriver test_drop_backing_job_driver = { 1471 .job_driver = { 1472 .instance_size = sizeof(TestDropBackingBlockJob), 1473 .free = block_job_free, 1474 .user_resume = block_job_user_resume, 1475 .run = test_drop_backing_job_run, 1476 .commit = test_drop_backing_job_commit, 1477 } 1478 }; 1479 1480 /** 1481 * Creates a child node with three parent nodes on it, and then runs a 1482 * block job on the final one, parent-node-2. 1483 * 1484 * The job is then asked to complete before a section where the child 1485 * is drained. 1486 * 1487 * Ending this section will undrain the child's parents, first 1488 * parent-node-2, then parent-node-1, then parent-node-0 -- the parent 1489 * list is in reverse order of how they were added. Ending the drain 1490 * on parent-node-2 will resume the job, thus completing it and 1491 * scheduling job_exit(). 1492 * 1493 * Ending the drain on parent-node-1 will poll the AioContext, which 1494 * lets job_exit() and thus test_drop_backing_job_commit() run. That 1495 * function first removes the child as parent-node-2's backing file. 1496 * 1497 * In old (and buggy) implementations, there are two problems with 1498 * that: 1499 * (A) bdrv_drain_invoke() polls for every node that leaves the 1500 * drained section. This means that job_exit() is scheduled 1501 * before the child has left the drained section. Its 1502 * quiesce_counter is therefore still 1 when it is removed from 1503 * parent-node-2. 1504 * 1505 * (B) bdrv_replace_child_noperm() calls drained_end() on the old 1506 * child's parents as many times as the child is quiesced. This 1507 * means it will call drained_end() on parent-node-2 once. 1508 * Because parent-node-2 is no longer quiesced at this point, this 1509 * will fail. 1510 * 1511 * bdrv_replace_child_noperm() therefore must call drained_end() on 1512 * the parent only if it really is still drained because the child is 1513 * drained. 1514 * 1515 * If removing child from parent-node-2 was successful (as it should 1516 * be), test_drop_backing_job_commit() will then also remove the child 1517 * from parent-node-0. 1518 * 1519 * With an old version of our drain infrastructure ((A) above), that 1520 * resulted in the following flow: 1521 * 1522 * 1. child attempts to leave its drained section. The call recurses 1523 * to its parents. 1524 * 1525 * 2. parent-node-2 leaves the drained section. Polling in 1526 * bdrv_drain_invoke() will schedule job_exit(). 1527 * 1528 * 3. parent-node-1 leaves the drained section. Polling in 1529 * bdrv_drain_invoke() will run job_exit(), thus disconnecting 1530 * parent-node-0 from the child node. 1531 * 1532 * 4. bdrv_parent_drained_end() uses a QLIST_FOREACH_SAFE() loop to 1533 * iterate over the parents. Thus, it now accesses the BdrvChild 1534 * object that used to connect parent-node-0 and the child node. 1535 * However, that object no longer exists, so it accesses a dangling 1536 * pointer. 1537 * 1538 * The solution is to only poll once when running a bdrv_drained_end() 1539 * operation, specifically at the end when all drained_end() 1540 * operations for all involved nodes have been scheduled. 1541 * Note that this also solves (A) above, thus hiding (B). 1542 */ 1543 static void test_blockjob_commit_by_drained_end(void) 1544 { 1545 BlockDriverState *bs_child, *bs_parents[3]; 1546 TestDropBackingBlockJob *job; 1547 bool job_has_completed = false; 1548 int i; 1549 1550 bs_child = bdrv_new_open_driver(&bdrv_test, "child-node", BDRV_O_RDWR, 1551 &error_abort); 1552 1553 for (i = 0; i < 3; i++) { 1554 char name[32]; 1555 snprintf(name, sizeof(name), "parent-node-%i", i); 1556 bs_parents[i] = bdrv_new_open_driver(&bdrv_test, name, BDRV_O_RDWR, 1557 &error_abort); 1558 bdrv_set_backing_hd(bs_parents[i], bs_child, &error_abort); 1559 } 1560 1561 job = block_job_create("job", &test_drop_backing_job_driver, NULL, 1562 bs_parents[2], 0, BLK_PERM_ALL, 0, 0, NULL, NULL, 1563 &error_abort); 1564 job->bs = bs_parents[2]; 1565 1566 job->detach_also = bs_parents[0]; 1567 job->did_complete = &job_has_completed; 1568 1569 job_start(&job->common.job); 1570 1571 job->should_complete = true; 1572 bdrv_drained_begin(bs_child); 1573 g_assert(!job_has_completed); 1574 bdrv_drained_end(bs_child); 1575 aio_poll(qemu_get_aio_context(), false); 1576 g_assert(job_has_completed); 1577 1578 bdrv_unref(bs_parents[0]); 1579 bdrv_unref(bs_parents[1]); 1580 bdrv_unref(bs_parents[2]); 1581 bdrv_unref(bs_child); 1582 } 1583 1584 1585 typedef struct TestSimpleBlockJob { 1586 BlockJob common; 1587 bool should_complete; 1588 bool *did_complete; 1589 } TestSimpleBlockJob; 1590 1591 static int coroutine_fn test_simple_job_run(Job *job, Error **errp) 1592 { 1593 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1594 1595 while (!s->should_complete) { 1596 job_sleep_ns(job, 0); 1597 } 1598 1599 return 0; 1600 } 1601 1602 static void test_simple_job_clean(Job *job) 1603 { 1604 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1605 *s->did_complete = true; 1606 } 1607 1608 static const BlockJobDriver test_simple_job_driver = { 1609 .job_driver = { 1610 .instance_size = sizeof(TestSimpleBlockJob), 1611 .free = block_job_free, 1612 .user_resume = block_job_user_resume, 1613 .run = test_simple_job_run, 1614 .clean = test_simple_job_clean, 1615 }, 1616 }; 1617 1618 static int drop_intermediate_poll_update_filename(BdrvChild *child, 1619 BlockDriverState *new_base, 1620 const char *filename, 1621 Error **errp) 1622 { 1623 /* 1624 * We are free to poll here, which may change the block graph, if 1625 * it is not drained. 1626 */ 1627 1628 /* If the job is not drained: Complete it, schedule job_exit() */ 1629 aio_poll(qemu_get_current_aio_context(), false); 1630 /* If the job is not drained: Run job_exit(), finish the job */ 1631 aio_poll(qemu_get_current_aio_context(), false); 1632 1633 return 0; 1634 } 1635 1636 /** 1637 * Test a poll in the midst of bdrv_drop_intermediate(). 1638 * 1639 * bdrv_drop_intermediate() calls BdrvChildClass.update_filename(), 1640 * which can yield or poll. This may lead to graph changes, unless 1641 * the whole subtree in question is drained. 1642 * 1643 * We test this on the following graph: 1644 * 1645 * Job 1646 * 1647 * | 1648 * job-node 1649 * | 1650 * v 1651 * 1652 * job-node 1653 * 1654 * | 1655 * backing 1656 * | 1657 * v 1658 * 1659 * node-2 --chain--> node-1 --chain--> node-0 1660 * 1661 * We drop node-1 with bdrv_drop_intermediate(top=node-1, base=node-0). 1662 * 1663 * This first updates node-2's backing filename by invoking 1664 * drop_intermediate_poll_update_filename(), which polls twice. This 1665 * causes the job to finish, which in turns causes the job-node to be 1666 * deleted. 1667 * 1668 * bdrv_drop_intermediate() uses a QLIST_FOREACH_SAFE() loop, so it 1669 * already has a pointer to the BdrvChild edge between job-node and 1670 * node-1. When it tries to handle that edge, we probably get a 1671 * segmentation fault because the object no longer exists. 1672 * 1673 * 1674 * The solution is for bdrv_drop_intermediate() to drain top's 1675 * subtree. This prevents graph changes from happening just because 1676 * BdrvChildClass.update_filename() yields or polls. Thus, the block 1677 * job is paused during that drained section and must finish before or 1678 * after. 1679 * 1680 * (In addition, bdrv_replace_child() must keep the job paused.) 1681 */ 1682 static void test_drop_intermediate_poll(void) 1683 { 1684 static BdrvChildClass chain_child_class; 1685 BlockDriverState *chain[3]; 1686 TestSimpleBlockJob *job; 1687 BlockDriverState *job_node; 1688 bool job_has_completed = false; 1689 int i; 1690 int ret; 1691 1692 chain_child_class = child_of_bds; 1693 chain_child_class.update_filename = drop_intermediate_poll_update_filename; 1694 1695 for (i = 0; i < 3; i++) { 1696 char name[32]; 1697 snprintf(name, 32, "node-%i", i); 1698 1699 chain[i] = bdrv_new_open_driver(&bdrv_test, name, 0, &error_abort); 1700 } 1701 1702 job_node = bdrv_new_open_driver(&bdrv_test, "job-node", BDRV_O_RDWR, 1703 &error_abort); 1704 bdrv_set_backing_hd(job_node, chain[1], &error_abort); 1705 1706 /* 1707 * Establish the chain last, so the chain links are the first 1708 * elements in the BDS.parents lists 1709 */ 1710 bdrv_graph_wrlock(NULL); 1711 for (i = 0; i < 3; i++) { 1712 if (i) { 1713 /* Takes the reference to chain[i - 1] */ 1714 bdrv_attach_child(chain[i], chain[i - 1], "chain", 1715 &chain_child_class, BDRV_CHILD_COW, &error_abort); 1716 } 1717 } 1718 bdrv_graph_wrunlock(); 1719 1720 job = block_job_create("job", &test_simple_job_driver, NULL, job_node, 1721 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort); 1722 1723 /* The job has a reference now */ 1724 bdrv_unref(job_node); 1725 1726 job->did_complete = &job_has_completed; 1727 1728 job_start(&job->common.job); 1729 job->should_complete = true; 1730 1731 g_assert(!job_has_completed); 1732 ret = bdrv_drop_intermediate(chain[1], chain[0], NULL); 1733 aio_poll(qemu_get_aio_context(), false); 1734 g_assert(ret == 0); 1735 g_assert(job_has_completed); 1736 1737 bdrv_unref(chain[2]); 1738 } 1739 1740 1741 typedef struct BDRVReplaceTestState { 1742 bool setup_completed; 1743 bool was_drained; 1744 bool was_undrained; 1745 bool has_read; 1746 1747 int drain_count; 1748 1749 bool yield_before_read; 1750 Coroutine *io_co; 1751 Coroutine *drain_co; 1752 } BDRVReplaceTestState; 1753 1754 static void bdrv_replace_test_close(BlockDriverState *bs) 1755 { 1756 } 1757 1758 /** 1759 * If @bs has a backing file: 1760 * Yield if .yield_before_read is true (and wait for drain_begin to 1761 * wake us up). 1762 * Forward the read to bs->backing. Set .has_read to true. 1763 * If drain_begin has woken us, wake it in turn. 1764 * 1765 * Otherwise: 1766 * Set .has_read to true and return success. 1767 */ 1768 static int coroutine_fn GRAPH_RDLOCK 1769 bdrv_replace_test_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 1770 QEMUIOVector *qiov, BdrvRequestFlags flags) 1771 { 1772 BDRVReplaceTestState *s = bs->opaque; 1773 1774 if (bs->backing) { 1775 int ret; 1776 1777 g_assert(!s->drain_count); 1778 1779 s->io_co = qemu_coroutine_self(); 1780 if (s->yield_before_read) { 1781 s->yield_before_read = false; 1782 qemu_coroutine_yield(); 1783 } 1784 s->io_co = NULL; 1785 1786 ret = bdrv_co_preadv(bs->backing, offset, bytes, qiov, 0); 1787 s->has_read = true; 1788 1789 /* Wake up drain_co if it runs */ 1790 if (s->drain_co) { 1791 aio_co_wake(s->drain_co); 1792 } 1793 1794 return ret; 1795 } 1796 1797 s->has_read = true; 1798 return 0; 1799 } 1800 1801 static void coroutine_fn bdrv_replace_test_drain_co(void *opaque) 1802 { 1803 BlockDriverState *bs = opaque; 1804 BDRVReplaceTestState *s = bs->opaque; 1805 1806 /* Keep waking io_co up until it is done */ 1807 while (s->io_co) { 1808 aio_co_wake(s->io_co); 1809 s->io_co = NULL; 1810 qemu_coroutine_yield(); 1811 } 1812 s->drain_co = NULL; 1813 bdrv_dec_in_flight(bs); 1814 } 1815 1816 /** 1817 * If .drain_count is 0, wake up .io_co if there is one; and set 1818 * .was_drained. 1819 * Increment .drain_count. 1820 */ 1821 static void bdrv_replace_test_drain_begin(BlockDriverState *bs) 1822 { 1823 BDRVReplaceTestState *s = bs->opaque; 1824 1825 if (!s->setup_completed) { 1826 return; 1827 } 1828 1829 if (!s->drain_count) { 1830 s->drain_co = qemu_coroutine_create(bdrv_replace_test_drain_co, bs); 1831 bdrv_inc_in_flight(bs); 1832 aio_co_enter(bdrv_get_aio_context(bs), s->drain_co); 1833 s->was_drained = true; 1834 } 1835 s->drain_count++; 1836 } 1837 1838 static void coroutine_fn bdrv_replace_test_read_entry(void *opaque) 1839 { 1840 BlockDriverState *bs = opaque; 1841 char data; 1842 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); 1843 int ret; 1844 1845 /* Queue a read request post-drain */ 1846 bdrv_graph_co_rdlock(); 1847 ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); 1848 bdrv_graph_co_rdunlock(); 1849 1850 g_assert(ret >= 0); 1851 bdrv_dec_in_flight(bs); 1852 } 1853 1854 /** 1855 * Reduce .drain_count, set .was_undrained once it reaches 0. 1856 * If .drain_count reaches 0 and the node has a backing file, issue a 1857 * read request. 1858 */ 1859 static void bdrv_replace_test_drain_end(BlockDriverState *bs) 1860 { 1861 BDRVReplaceTestState *s = bs->opaque; 1862 1863 if (!s->setup_completed) { 1864 return; 1865 } 1866 1867 g_assert(s->drain_count > 0); 1868 if (!--s->drain_count) { 1869 s->was_undrained = true; 1870 1871 if (bs->backing) { 1872 Coroutine *co = qemu_coroutine_create(bdrv_replace_test_read_entry, 1873 bs); 1874 bdrv_inc_in_flight(bs); 1875 aio_co_enter(bdrv_get_aio_context(bs), co); 1876 } 1877 } 1878 } 1879 1880 static BlockDriver bdrv_replace_test = { 1881 .format_name = "replace_test", 1882 .instance_size = sizeof(BDRVReplaceTestState), 1883 .supports_backing = true, 1884 1885 .bdrv_close = bdrv_replace_test_close, 1886 .bdrv_co_preadv = bdrv_replace_test_co_preadv, 1887 1888 .bdrv_drain_begin = bdrv_replace_test_drain_begin, 1889 .bdrv_drain_end = bdrv_replace_test_drain_end, 1890 1891 .bdrv_child_perm = bdrv_default_perms, 1892 }; 1893 1894 static void coroutine_fn test_replace_child_mid_drain_read_co(void *opaque) 1895 { 1896 int ret; 1897 char data; 1898 1899 ret = blk_co_pread(opaque, 0, 1, &data, 0); 1900 g_assert(ret >= 0); 1901 } 1902 1903 /** 1904 * We test two things: 1905 * (1) bdrv_replace_child_noperm() must not undrain the parent if both 1906 * children are drained. 1907 * (2) bdrv_replace_child_noperm() must never flush I/O requests to a 1908 * drained child. If the old child is drained, it must flush I/O 1909 * requests after the new one has been attached. If the new child 1910 * is drained, it must flush I/O requests before the old one is 1911 * detached. 1912 * 1913 * To do so, we create one parent node and two child nodes; then 1914 * attach one of the children (old_child_bs) to the parent, then 1915 * drain both old_child_bs and new_child_bs according to 1916 * old_drain_count and new_drain_count, respectively, and finally 1917 * we invoke bdrv_replace_node() to replace old_child_bs by 1918 * new_child_bs. 1919 * 1920 * The test block driver we use here (bdrv_replace_test) has a read 1921 * function that: 1922 * - For the parent node, can optionally yield, and then forwards the 1923 * read to bdrv_preadv(), 1924 * - For the child node, just returns immediately. 1925 * 1926 * If the read yields, the drain_begin function will wake it up. 1927 * 1928 * The drain_end function issues a read on the parent once it is fully 1929 * undrained (which simulates requests starting to come in again). 1930 */ 1931 static void do_test_replace_child_mid_drain(int old_drain_count, 1932 int new_drain_count) 1933 { 1934 BlockBackend *parent_blk; 1935 BlockDriverState *parent_bs; 1936 BlockDriverState *old_child_bs, *new_child_bs; 1937 BDRVReplaceTestState *parent_s; 1938 BDRVReplaceTestState *old_child_s, *new_child_s; 1939 Coroutine *io_co; 1940 int i; 1941 1942 parent_bs = bdrv_new_open_driver(&bdrv_replace_test, "parent", 0, 1943 &error_abort); 1944 parent_s = parent_bs->opaque; 1945 1946 parent_blk = blk_new(qemu_get_aio_context(), 1947 BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL); 1948 blk_insert_bs(parent_blk, parent_bs, &error_abort); 1949 1950 old_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "old-child", 0, 1951 &error_abort); 1952 new_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "new-child", 0, 1953 &error_abort); 1954 old_child_s = old_child_bs->opaque; 1955 new_child_s = new_child_bs->opaque; 1956 1957 /* So that we can read something */ 1958 parent_bs->total_sectors = 1; 1959 old_child_bs->total_sectors = 1; 1960 new_child_bs->total_sectors = 1; 1961 1962 bdrv_ref(old_child_bs); 1963 bdrv_graph_wrlock(NULL); 1964 bdrv_attach_child(parent_bs, old_child_bs, "child", &child_of_bds, 1965 BDRV_CHILD_COW, &error_abort); 1966 bdrv_graph_wrunlock(); 1967 parent_s->setup_completed = true; 1968 1969 for (i = 0; i < old_drain_count; i++) { 1970 bdrv_drained_begin(old_child_bs); 1971 } 1972 for (i = 0; i < new_drain_count; i++) { 1973 bdrv_drained_begin(new_child_bs); 1974 } 1975 1976 if (!old_drain_count) { 1977 /* 1978 * Start a read operation that will yield, so it will not 1979 * complete before the node is drained. 1980 */ 1981 parent_s->yield_before_read = true; 1982 io_co = qemu_coroutine_create(test_replace_child_mid_drain_read_co, 1983 parent_blk); 1984 qemu_coroutine_enter(io_co); 1985 } 1986 1987 /* If we have started a read operation, it should have yielded */ 1988 g_assert(!parent_s->has_read); 1989 1990 /* Reset drained status so we can see what bdrv_replace_node() does */ 1991 parent_s->was_drained = false; 1992 parent_s->was_undrained = false; 1993 1994 g_assert(parent_bs->quiesce_counter == old_drain_count); 1995 bdrv_replace_node(old_child_bs, new_child_bs, &error_abort); 1996 g_assert(parent_bs->quiesce_counter == new_drain_count); 1997 1998 if (!old_drain_count && !new_drain_count) { 1999 /* 2000 * From undrained to undrained drains and undrains the parent, 2001 * because bdrv_replace_node() contains a drained section for 2002 * @old_child_bs. 2003 */ 2004 g_assert(parent_s->was_drained && parent_s->was_undrained); 2005 } else if (!old_drain_count && new_drain_count) { 2006 /* 2007 * From undrained to drained should drain the parent and keep 2008 * it that way. 2009 */ 2010 g_assert(parent_s->was_drained && !parent_s->was_undrained); 2011 } else if (old_drain_count && !new_drain_count) { 2012 /* 2013 * From drained to undrained should undrain the parent and 2014 * keep it that way. 2015 */ 2016 g_assert(!parent_s->was_drained && parent_s->was_undrained); 2017 } else /* if (old_drain_count && new_drain_count) */ { 2018 /* 2019 * From drained to drained must not undrain the parent at any 2020 * point 2021 */ 2022 g_assert(!parent_s->was_drained && !parent_s->was_undrained); 2023 } 2024 2025 if (!old_drain_count || !new_drain_count) { 2026 /* 2027 * If !old_drain_count, we have started a read request before 2028 * bdrv_replace_node(). If !new_drain_count, the parent must 2029 * have been undrained at some point, and 2030 * bdrv_replace_test_co_drain_end() starts a read request 2031 * then. 2032 */ 2033 g_assert(parent_s->has_read); 2034 } else { 2035 /* 2036 * If the parent was never undrained, there is no way to start 2037 * a read request. 2038 */ 2039 g_assert(!parent_s->has_read); 2040 } 2041 2042 /* A drained child must have not received any request */ 2043 g_assert(!(old_drain_count && old_child_s->has_read)); 2044 g_assert(!(new_drain_count && new_child_s->has_read)); 2045 2046 for (i = 0; i < new_drain_count; i++) { 2047 bdrv_drained_end(new_child_bs); 2048 } 2049 for (i = 0; i < old_drain_count; i++) { 2050 bdrv_drained_end(old_child_bs); 2051 } 2052 2053 /* 2054 * By now, bdrv_replace_test_co_drain_end() must have been called 2055 * at some point while the new child was attached to the parent. 2056 */ 2057 g_assert(parent_s->has_read); 2058 g_assert(new_child_s->has_read); 2059 2060 blk_unref(parent_blk); 2061 bdrv_unref(parent_bs); 2062 bdrv_unref(old_child_bs); 2063 bdrv_unref(new_child_bs); 2064 } 2065 2066 static void test_replace_child_mid_drain(void) 2067 { 2068 int old_drain_count, new_drain_count; 2069 2070 for (old_drain_count = 0; old_drain_count < 2; old_drain_count++) { 2071 for (new_drain_count = 0; new_drain_count < 2; new_drain_count++) { 2072 do_test_replace_child_mid_drain(old_drain_count, new_drain_count); 2073 } 2074 } 2075 } 2076 2077 int main(int argc, char **argv) 2078 { 2079 int ret; 2080 2081 bdrv_init(); 2082 qemu_init_main_loop(&error_abort); 2083 2084 g_test_init(&argc, &argv, NULL); 2085 qemu_event_init(&done_event, false); 2086 2087 g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all); 2088 g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain); 2089 2090 g_test_add_func("/bdrv-drain/driver-cb/co/drain_all", 2091 test_drv_cb_co_drain_all); 2092 g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain); 2093 2094 g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all); 2095 g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain); 2096 2097 g_test_add_func("/bdrv-drain/quiesce/co/drain_all", 2098 test_quiesce_co_drain_all); 2099 g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain); 2100 2101 g_test_add_func("/bdrv-drain/nested", test_nested); 2102 2103 g_test_add_func("/bdrv-drain/graph-change/drain_all", 2104 test_graph_change_drain_all); 2105 2106 g_test_add_func("/bdrv-drain/iothread/drain_all", test_iothread_drain_all); 2107 g_test_add_func("/bdrv-drain/iothread/drain", test_iothread_drain); 2108 2109 g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all); 2110 g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain); 2111 2112 g_test_add_func("/bdrv-drain/blockjob/error/drain_all", 2113 test_blockjob_error_drain_all); 2114 g_test_add_func("/bdrv-drain/blockjob/error/drain", 2115 test_blockjob_error_drain); 2116 2117 g_test_add_func("/bdrv-drain/blockjob/iothread/drain_all", 2118 test_blockjob_iothread_drain_all); 2119 g_test_add_func("/bdrv-drain/blockjob/iothread/drain", 2120 test_blockjob_iothread_drain); 2121 2122 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_all", 2123 test_blockjob_iothread_error_drain_all); 2124 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain", 2125 test_blockjob_iothread_error_drain); 2126 2127 g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain); 2128 g_test_add_func("/bdrv-drain/detach/drain_all", test_detach_by_drain_all); 2129 g_test_add_func("/bdrv-drain/detach/drain", test_detach_by_drain); 2130 g_test_add_func("/bdrv-drain/detach/parent_cb", test_detach_by_parent_cb); 2131 g_test_add_func("/bdrv-drain/detach/driver_cb", test_detach_by_driver_cb); 2132 2133 g_test_add_func("/bdrv-drain/attach/drain", test_append_to_drained); 2134 2135 g_test_add_func("/bdrv-drain/set_aio_context", test_set_aio_context); 2136 2137 g_test_add_func("/bdrv-drain/blockjob/commit_by_drained_end", 2138 test_blockjob_commit_by_drained_end); 2139 2140 g_test_add_func("/bdrv-drain/bdrv_drop_intermediate/poll", 2141 test_drop_intermediate_poll); 2142 2143 g_test_add_func("/bdrv-drain/replace_child/mid-drain", 2144 test_replace_child_mid_drain); 2145 2146 ret = g_test_run(); 2147 qemu_event_destroy(&done_event); 2148 return ret; 2149 } 2150