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_co_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_co_change_backing_file = bdrv_test_co_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 do_drain_begin(drain_type, bs); 183 } 184 185 static BlockBackend * no_coroutine_fn test_setup(void) 186 { 187 BlockBackend *blk; 188 BlockDriverState *bs, *backing; 189 190 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 191 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 192 &error_abort); 193 blk_insert_bs(blk, bs, &error_abort); 194 195 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 196 bdrv_set_backing_hd(bs, backing, &error_abort); 197 198 bdrv_unref(backing); 199 bdrv_unref(bs); 200 201 return blk; 202 } 203 204 static void do_drain_end_unlocked(enum drain_type drain_type, BlockDriverState *bs) 205 { 206 do_drain_end(drain_type, bs); 207 } 208 209 /* 210 * Locking the block graph would be a bit cumbersome here because this function 211 * is called both in coroutine and non-coroutine context. We know this is a test 212 * and nothing else is running, so don't bother with TSA. 213 */ 214 static void coroutine_mixed_fn TSA_NO_TSA 215 test_drv_cb_common(BlockBackend *blk, enum drain_type drain_type, 216 bool recursive) 217 { 218 BlockDriverState *bs = blk_bs(blk); 219 BlockDriverState *backing = bs->backing->bs; 220 BDRVTestState *s, *backing_s; 221 BlockAIOCB *acb; 222 int aio_ret; 223 224 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 225 226 s = bs->opaque; 227 backing_s = backing->opaque; 228 229 /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */ 230 g_assert_cmpint(s->drain_count, ==, 0); 231 g_assert_cmpint(backing_s->drain_count, ==, 0); 232 233 do_drain_begin(drain_type, bs); 234 235 g_assert_cmpint(s->drain_count, ==, 1); 236 g_assert_cmpint(backing_s->drain_count, ==, !!recursive); 237 238 do_drain_end(drain_type, bs); 239 240 g_assert_cmpint(s->drain_count, ==, 0); 241 g_assert_cmpint(backing_s->drain_count, ==, 0); 242 243 /* Now do the same while a request is pending */ 244 aio_ret = -EINPROGRESS; 245 acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); 246 g_assert(acb != NULL); 247 g_assert_cmpint(aio_ret, ==, -EINPROGRESS); 248 249 g_assert_cmpint(s->drain_count, ==, 0); 250 g_assert_cmpint(backing_s->drain_count, ==, 0); 251 252 do_drain_begin(drain_type, bs); 253 254 g_assert_cmpint(aio_ret, ==, 0); 255 g_assert_cmpint(s->drain_count, ==, 1); 256 g_assert_cmpint(backing_s->drain_count, ==, !!recursive); 257 258 do_drain_end(drain_type, bs); 259 260 g_assert_cmpint(s->drain_count, ==, 0); 261 g_assert_cmpint(backing_s->drain_count, ==, 0); 262 } 263 264 static void test_drv_cb_drain_all(void) 265 { 266 BlockBackend *blk = test_setup(); 267 test_drv_cb_common(blk, BDRV_DRAIN_ALL, true); 268 blk_unref(blk); 269 } 270 271 static void test_drv_cb_drain(void) 272 { 273 BlockBackend *blk = test_setup(); 274 test_drv_cb_common(blk, BDRV_DRAIN, false); 275 blk_unref(blk); 276 } 277 278 static void coroutine_fn test_drv_cb_co_drain_all_entry(void) 279 { 280 BlockBackend *blk = blk_all_next(NULL); 281 test_drv_cb_common(blk, BDRV_DRAIN_ALL, true); 282 } 283 284 static void test_drv_cb_co_drain_all(void) 285 { 286 BlockBackend *blk = test_setup(); 287 call_in_coroutine(test_drv_cb_co_drain_all_entry); 288 blk_unref(blk); 289 } 290 291 static void coroutine_fn test_drv_cb_co_drain_entry(void) 292 { 293 BlockBackend *blk = blk_all_next(NULL); 294 test_drv_cb_common(blk, BDRV_DRAIN, false); 295 } 296 297 static void test_drv_cb_co_drain(void) 298 { 299 BlockBackend *blk = test_setup(); 300 call_in_coroutine(test_drv_cb_co_drain_entry); 301 blk_unref(blk); 302 } 303 304 /* 305 * Locking the block graph would be a bit cumbersome here because this function 306 * is called both in coroutine and non-coroutine context. We know this is a test 307 * and nothing else is running, so don't bother with TSA. 308 */ 309 static void coroutine_mixed_fn TSA_NO_TSA 310 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 bdrv_flush(data->bs); 512 bdrv_dec_in_flight(data->bs); /* incremented by test_iothread_common() */ 513 } 514 515 /* 516 * Starts an AIO request on a BDS that runs in the AioContext of iothread 1. 517 * The request involves a BH on iothread 2 before it can complete. 518 * 519 * @drain_thread = 0 means that do_drain_begin/end are called from the main 520 * thread, @drain_thread = 1 means that they are called from iothread 1. Drain 521 * for this BDS cannot be called from iothread 2 because only the main thread 522 * may do cross-AioContext polling. 523 */ 524 static void test_iothread_common(enum drain_type drain_type, int drain_thread) 525 { 526 BlockBackend *blk; 527 BlockDriverState *bs; 528 BDRVTestState *s; 529 BlockAIOCB *acb; 530 Coroutine *co; 531 int aio_ret; 532 struct test_iothread_data data; 533 534 IOThread *a = iothread_new(); 535 IOThread *b = iothread_new(); 536 AioContext *ctx_a = iothread_get_aio_context(a); 537 AioContext *ctx_b = iothread_get_aio_context(b); 538 539 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 540 541 /* bdrv_drain_all() may only be called from the main loop thread */ 542 if (drain_type == BDRV_DRAIN_ALL && drain_thread != 0) { 543 goto out; 544 } 545 546 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 547 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 548 &error_abort); 549 s = bs->opaque; 550 blk_insert_bs(blk, bs, &error_abort); 551 blk_set_disable_request_queuing(blk, true); 552 553 blk_set_aio_context(blk, ctx_a, &error_abort); 554 555 s->bh_indirection_ctx = ctx_b; 556 557 aio_ret = -EINPROGRESS; 558 qemu_event_reset(&done_event); 559 560 if (drain_thread == 0) { 561 acb = blk_aio_preadv(blk, 0, &qiov, 0, test_iothread_aio_cb, &aio_ret); 562 } else { 563 acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); 564 } 565 g_assert(acb != NULL); 566 g_assert_cmpint(aio_ret, ==, -EINPROGRESS); 567 568 data = (struct test_iothread_data) { 569 .bs = bs, 570 .drain_type = drain_type, 571 .aio_ret = &aio_ret, 572 }; 573 574 switch (drain_thread) { 575 case 0: 576 /* 577 * Increment in_flight so that do_drain_begin() waits for 578 * test_iothread_main_thread_bh(). This prevents the race between 579 * test_iothread_main_thread_bh() in IOThread a and do_drain_begin() in 580 * this thread. test_iothread_main_thread_bh() decrements in_flight. 581 */ 582 bdrv_inc_in_flight(bs); 583 aio_bh_schedule_oneshot(ctx_a, test_iothread_main_thread_bh, &data); 584 585 /* The request is running on the IOThread a. Draining its block device 586 * will make sure that it has completed as far as the BDS is concerned, 587 * but the drain in this thread can continue immediately after 588 * bdrv_dec_in_flight() and aio_ret might be assigned only slightly 589 * later. */ 590 do_drain_begin(drain_type, bs); 591 g_assert_cmpint(bs->in_flight, ==, 0); 592 593 qemu_event_wait(&done_event); 594 595 g_assert_cmpint(aio_ret, ==, 0); 596 do_drain_end(drain_type, bs); 597 break; 598 case 1: 599 co = qemu_coroutine_create(test_iothread_drain_co_entry, &data); 600 aio_co_enter(ctx_a, co); 601 AIO_WAIT_WHILE_UNLOCKED(NULL, !data.co_done); 602 break; 603 default: 604 g_assert_not_reached(); 605 } 606 607 blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort); 608 609 bdrv_unref(bs); 610 blk_unref(blk); 611 612 out: 613 iothread_join(a); 614 iothread_join(b); 615 } 616 617 static void test_iothread_drain_all(void) 618 { 619 test_iothread_common(BDRV_DRAIN_ALL, 0); 620 test_iothread_common(BDRV_DRAIN_ALL, 1); 621 } 622 623 static void test_iothread_drain(void) 624 { 625 test_iothread_common(BDRV_DRAIN, 0); 626 test_iothread_common(BDRV_DRAIN, 1); 627 } 628 629 630 typedef struct TestBlockJob { 631 BlockJob common; 632 BlockDriverState *bs; 633 int run_ret; 634 int prepare_ret; 635 bool running; 636 bool should_complete; 637 } TestBlockJob; 638 639 static int test_job_prepare(Job *job) 640 { 641 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 642 643 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 644 bdrv_flush(s->bs); 645 return s->prepare_ret; 646 } 647 648 static void test_job_commit(Job *job) 649 { 650 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 651 652 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 653 bdrv_flush(s->bs); 654 } 655 656 static void test_job_abort(Job *job) 657 { 658 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 659 660 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 661 bdrv_flush(s->bs); 662 } 663 664 static int coroutine_fn test_job_run(Job *job, Error **errp) 665 { 666 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 667 668 /* We are running the actual job code past the pause point in 669 * job_co_entry(). */ 670 s->running = true; 671 672 job_transition_to_ready(&s->common.job); 673 while (!s->should_complete) { 674 /* Avoid job_sleep_ns() because it marks the job as !busy. We want to 675 * emulate some actual activity (probably some I/O) here so that drain 676 * has to wait for this activity to stop. */ 677 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); 678 679 job_pause_point(&s->common.job); 680 } 681 682 return s->run_ret; 683 } 684 685 static void test_job_complete(Job *job, Error **errp) 686 { 687 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 688 s->should_complete = true; 689 } 690 691 BlockJobDriver test_job_driver = { 692 .job_driver = { 693 .instance_size = sizeof(TestBlockJob), 694 .free = block_job_free, 695 .user_resume = block_job_user_resume, 696 .run = test_job_run, 697 .complete = test_job_complete, 698 .prepare = test_job_prepare, 699 .commit = test_job_commit, 700 .abort = test_job_abort, 701 }, 702 }; 703 704 enum test_job_result { 705 TEST_JOB_SUCCESS, 706 TEST_JOB_FAIL_RUN, 707 TEST_JOB_FAIL_PREPARE, 708 }; 709 710 enum test_job_drain_node { 711 TEST_JOB_DRAIN_SRC, 712 TEST_JOB_DRAIN_SRC_CHILD, 713 }; 714 715 static void test_blockjob_common_drain_node(enum drain_type drain_type, 716 bool use_iothread, 717 enum test_job_result result, 718 enum test_job_drain_node drain_node) 719 { 720 BlockBackend *blk_src, *blk_target; 721 BlockDriverState *src, *src_backing, *src_overlay, *target, *drain_bs; 722 BlockJob *job; 723 TestBlockJob *tjob; 724 IOThread *iothread = NULL; 725 int ret; 726 727 src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR, 728 &error_abort); 729 src_backing = bdrv_new_open_driver(&bdrv_test, "source-backing", 730 BDRV_O_RDWR, &error_abort); 731 src_overlay = bdrv_new_open_driver(&bdrv_test, "source-overlay", 732 BDRV_O_RDWR, &error_abort); 733 734 bdrv_set_backing_hd(src_overlay, src, &error_abort); 735 bdrv_unref(src); 736 bdrv_set_backing_hd(src, src_backing, &error_abort); 737 bdrv_unref(src_backing); 738 739 blk_src = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 740 blk_insert_bs(blk_src, src_overlay, &error_abort); 741 742 switch (drain_node) { 743 case TEST_JOB_DRAIN_SRC: 744 drain_bs = src; 745 break; 746 case TEST_JOB_DRAIN_SRC_CHILD: 747 drain_bs = src_backing; 748 break; 749 default: 750 g_assert_not_reached(); 751 } 752 753 if (use_iothread) { 754 AioContext *ctx; 755 756 iothread = iothread_new(); 757 ctx = iothread_get_aio_context(iothread); 758 blk_set_aio_context(blk_src, ctx, &error_abort); 759 } 760 761 target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR, 762 &error_abort); 763 blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 764 blk_insert_bs(blk_target, target, &error_abort); 765 blk_set_allow_aio_context_change(blk_target, true); 766 767 tjob = block_job_create("job0", &test_job_driver, NULL, src, 768 0, BLK_PERM_ALL, 769 0, 0, NULL, NULL, &error_abort); 770 tjob->bs = src; 771 job = &tjob->common; 772 773 bdrv_graph_wrlock(); 774 block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort); 775 bdrv_graph_wrunlock(); 776 777 switch (result) { 778 case TEST_JOB_SUCCESS: 779 break; 780 case TEST_JOB_FAIL_RUN: 781 tjob->run_ret = -EIO; 782 break; 783 case TEST_JOB_FAIL_PREPARE: 784 tjob->prepare_ret = -EIO; 785 break; 786 } 787 788 job_start(&job->job); 789 790 if (use_iothread) { 791 /* job_co_entry() is run in the I/O thread, wait for the actual job 792 * code to start (we don't want to catch the job in the pause point in 793 * job_co_entry(). */ 794 while (!tjob->running) { 795 aio_poll(qemu_get_aio_context(), false); 796 } 797 } 798 799 WITH_JOB_LOCK_GUARD() { 800 g_assert_cmpint(job->job.pause_count, ==, 0); 801 g_assert_false(job->job.paused); 802 g_assert_true(tjob->running); 803 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 804 } 805 806 do_drain_begin_unlocked(drain_type, drain_bs); 807 808 WITH_JOB_LOCK_GUARD() { 809 if (drain_type == BDRV_DRAIN_ALL) { 810 /* bdrv_drain_all() drains both src and target */ 811 g_assert_cmpint(job->job.pause_count, ==, 2); 812 } else { 813 g_assert_cmpint(job->job.pause_count, ==, 1); 814 } 815 g_assert_true(job->job.paused); 816 g_assert_false(job->job.busy); /* The job is paused */ 817 } 818 819 do_drain_end_unlocked(drain_type, drain_bs); 820 821 if (use_iothread) { 822 /* 823 * Here we are waiting for the paused status to change, 824 * so don't bother protecting the read every time. 825 * 826 * paused is reset in the I/O thread, wait for it 827 */ 828 while (job->job.paused) { 829 aio_poll(qemu_get_aio_context(), false); 830 } 831 } 832 833 WITH_JOB_LOCK_GUARD() { 834 g_assert_cmpint(job->job.pause_count, ==, 0); 835 g_assert_false(job->job.paused); 836 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 837 } 838 839 do_drain_begin_unlocked(drain_type, target); 840 841 WITH_JOB_LOCK_GUARD() { 842 if (drain_type == BDRV_DRAIN_ALL) { 843 /* bdrv_drain_all() drains both src and target */ 844 g_assert_cmpint(job->job.pause_count, ==, 2); 845 } else { 846 g_assert_cmpint(job->job.pause_count, ==, 1); 847 } 848 g_assert_true(job->job.paused); 849 g_assert_false(job->job.busy); /* The job is paused */ 850 } 851 852 do_drain_end_unlocked(drain_type, target); 853 854 if (use_iothread) { 855 /* 856 * Here we are waiting for the paused status to change, 857 * so don't bother protecting the read every time. 858 * 859 * paused is reset in the I/O thread, wait for it 860 */ 861 while (job->job.paused) { 862 aio_poll(qemu_get_aio_context(), false); 863 } 864 } 865 866 WITH_JOB_LOCK_GUARD() { 867 g_assert_cmpint(job->job.pause_count, ==, 0); 868 g_assert_false(job->job.paused); 869 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 870 } 871 872 WITH_JOB_LOCK_GUARD() { 873 ret = job_complete_sync_locked(&job->job, &error_abort); 874 } 875 g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO)); 876 877 if (use_iothread) { 878 blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort); 879 assert(blk_get_aio_context(blk_target) == qemu_get_aio_context()); 880 } 881 882 blk_unref(blk_src); 883 blk_unref(blk_target); 884 bdrv_unref(src_overlay); 885 bdrv_unref(target); 886 887 if (iothread) { 888 iothread_join(iothread); 889 } 890 } 891 892 static void test_blockjob_common(enum drain_type drain_type, bool use_iothread, 893 enum test_job_result result) 894 { 895 test_blockjob_common_drain_node(drain_type, use_iothread, result, 896 TEST_JOB_DRAIN_SRC); 897 test_blockjob_common_drain_node(drain_type, use_iothread, result, 898 TEST_JOB_DRAIN_SRC_CHILD); 899 } 900 901 static void test_blockjob_drain_all(void) 902 { 903 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS); 904 } 905 906 static void test_blockjob_drain(void) 907 { 908 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_SUCCESS); 909 } 910 911 static void test_blockjob_error_drain_all(void) 912 { 913 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_RUN); 914 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_PREPARE); 915 } 916 917 static void test_blockjob_error_drain(void) 918 { 919 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_RUN); 920 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_PREPARE); 921 } 922 923 static void test_blockjob_iothread_drain_all(void) 924 { 925 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_SUCCESS); 926 } 927 928 static void test_blockjob_iothread_drain(void) 929 { 930 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_SUCCESS); 931 } 932 933 static void test_blockjob_iothread_error_drain_all(void) 934 { 935 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_RUN); 936 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_PREPARE); 937 } 938 939 static void test_blockjob_iothread_error_drain(void) 940 { 941 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_RUN); 942 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_PREPARE); 943 } 944 945 946 typedef struct BDRVTestTopState { 947 BdrvChild *wait_child; 948 } BDRVTestTopState; 949 950 static void bdrv_test_top_close(BlockDriverState *bs) 951 { 952 BdrvChild *c, *next_c; 953 954 bdrv_graph_wrlock(); 955 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 956 bdrv_unref_child(bs, c); 957 } 958 bdrv_graph_wrunlock(); 959 } 960 961 static int coroutine_fn GRAPH_RDLOCK 962 bdrv_test_top_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 963 QEMUIOVector *qiov, BdrvRequestFlags flags) 964 { 965 BDRVTestTopState *tts = bs->opaque; 966 return bdrv_co_preadv(tts->wait_child, offset, bytes, qiov, flags); 967 } 968 969 static BlockDriver bdrv_test_top_driver = { 970 .format_name = "test_top_driver", 971 .instance_size = sizeof(BDRVTestTopState), 972 973 .bdrv_close = bdrv_test_top_close, 974 .bdrv_co_preadv = bdrv_test_top_co_preadv, 975 976 .bdrv_child_perm = bdrv_default_perms, 977 }; 978 979 typedef struct TestCoDeleteByDrainData { 980 BlockBackend *blk; 981 bool detach_instead_of_delete; 982 bool done; 983 } TestCoDeleteByDrainData; 984 985 static void coroutine_fn test_co_delete_by_drain(void *opaque) 986 { 987 TestCoDeleteByDrainData *dbdd = opaque; 988 BlockBackend *blk = dbdd->blk; 989 BlockDriverState *bs = blk_bs(blk); 990 BDRVTestTopState *tts = bs->opaque; 991 void *buffer = g_malloc(65536); 992 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buffer, 65536); 993 994 /* Pretend some internal write operation from parent to child. 995 * Important: We have to read from the child, not from the parent! 996 * Draining works by first propagating it all up the tree to the 997 * root and then waiting for drainage from root to the leaves 998 * (protocol nodes). If we have a request waiting on the root, 999 * everything will be drained before we go back down the tree, but 1000 * we do not want that. We want to be in the middle of draining 1001 * when this following requests returns. */ 1002 bdrv_graph_co_rdlock(); 1003 bdrv_co_preadv(tts->wait_child, 0, 65536, &qiov, 0); 1004 bdrv_graph_co_rdunlock(); 1005 1006 g_assert_cmpint(bs->refcnt, ==, 1); 1007 1008 if (!dbdd->detach_instead_of_delete) { 1009 blk_co_unref(blk); 1010 } else { 1011 BdrvChild *c, *next_c; 1012 bdrv_graph_co_rdlock(); 1013 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 1014 bdrv_graph_co_rdunlock(); 1015 bdrv_co_unref_child(bs, c); 1016 bdrv_graph_co_rdlock(); 1017 } 1018 bdrv_graph_co_rdunlock(); 1019 } 1020 1021 dbdd->done = true; 1022 g_free(buffer); 1023 } 1024 1025 /** 1026 * Test what happens when some BDS has some children, you drain one of 1027 * them and this results in the BDS being deleted. 1028 * 1029 * If @detach_instead_of_delete is set, the BDS is not going to be 1030 * deleted but will only detach all of its children. 1031 */ 1032 static void do_test_delete_by_drain(bool detach_instead_of_delete, 1033 enum drain_type drain_type) 1034 { 1035 BlockBackend *blk; 1036 BlockDriverState *bs, *child_bs, *null_bs; 1037 BDRVTestTopState *tts; 1038 TestCoDeleteByDrainData dbdd; 1039 Coroutine *co; 1040 1041 bs = bdrv_new_open_driver(&bdrv_test_top_driver, "top", BDRV_O_RDWR, 1042 &error_abort); 1043 bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1044 tts = bs->opaque; 1045 1046 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1047 &error_abort); 1048 bdrv_graph_wrlock(); 1049 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, 1050 BDRV_CHILD_DATA, &error_abort); 1051 bdrv_graph_wrunlock(); 1052 1053 /* This child will be the one to pass to requests through to, and 1054 * it will stall until a drain occurs */ 1055 child_bs = bdrv_new_open_driver(&bdrv_test, "child", BDRV_O_RDWR, 1056 &error_abort); 1057 child_bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1058 /* Takes our reference to child_bs */ 1059 bdrv_graph_wrlock(); 1060 tts->wait_child = bdrv_attach_child(bs, child_bs, "wait-child", 1061 &child_of_bds, 1062 BDRV_CHILD_DATA | BDRV_CHILD_PRIMARY, 1063 &error_abort); 1064 bdrv_graph_wrunlock(); 1065 1066 /* This child is just there to be deleted 1067 * (for detach_instead_of_delete == true) */ 1068 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1069 &error_abort); 1070 bdrv_graph_wrlock(); 1071 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, BDRV_CHILD_DATA, 1072 &error_abort); 1073 bdrv_graph_wrunlock(); 1074 1075 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1076 blk_insert_bs(blk, bs, &error_abort); 1077 1078 /* Referenced by blk now */ 1079 bdrv_unref(bs); 1080 1081 g_assert_cmpint(bs->refcnt, ==, 1); 1082 g_assert_cmpint(child_bs->refcnt, ==, 1); 1083 g_assert_cmpint(null_bs->refcnt, ==, 1); 1084 1085 1086 dbdd = (TestCoDeleteByDrainData){ 1087 .blk = blk, 1088 .detach_instead_of_delete = detach_instead_of_delete, 1089 .done = false, 1090 }; 1091 co = qemu_coroutine_create(test_co_delete_by_drain, &dbdd); 1092 qemu_coroutine_enter(co); 1093 1094 /* Drain the child while the read operation is still pending. 1095 * This should result in the operation finishing and 1096 * test_co_delete_by_drain() resuming. Thus, @bs will be deleted 1097 * and the coroutine will exit while this drain operation is still 1098 * in progress. */ 1099 switch (drain_type) { 1100 case BDRV_DRAIN: 1101 bdrv_ref(child_bs); 1102 bdrv_drain(child_bs); 1103 bdrv_unref(child_bs); 1104 break; 1105 case BDRV_DRAIN_ALL: 1106 bdrv_drain_all_begin(); 1107 bdrv_drain_all_end(); 1108 break; 1109 default: 1110 g_assert_not_reached(); 1111 } 1112 1113 while (!dbdd.done) { 1114 aio_poll(qemu_get_aio_context(), true); 1115 } 1116 1117 if (detach_instead_of_delete) { 1118 /* Here, the reference has not passed over to the coroutine, 1119 * so we have to delete the BB ourselves */ 1120 blk_unref(blk); 1121 } 1122 } 1123 1124 static void test_delete_by_drain(void) 1125 { 1126 do_test_delete_by_drain(false, BDRV_DRAIN); 1127 } 1128 1129 static void test_detach_by_drain_all(void) 1130 { 1131 do_test_delete_by_drain(true, BDRV_DRAIN_ALL); 1132 } 1133 1134 static void test_detach_by_drain(void) 1135 { 1136 do_test_delete_by_drain(true, BDRV_DRAIN); 1137 } 1138 1139 1140 struct detach_by_parent_data { 1141 BlockDriverState *parent_b; 1142 BdrvChild *child_b; 1143 BlockDriverState *c; 1144 BdrvChild *child_c; 1145 bool by_parent_cb; 1146 bool detach_on_drain; 1147 }; 1148 static struct detach_by_parent_data detach_by_parent_data; 1149 1150 static void no_coroutine_fn detach_indirect_bh(void *opaque) 1151 { 1152 struct detach_by_parent_data *data = opaque; 1153 1154 bdrv_dec_in_flight(data->child_b->bs); 1155 1156 bdrv_graph_wrlock(); 1157 bdrv_unref_child(data->parent_b, data->child_b); 1158 1159 bdrv_ref(data->c); 1160 data->child_c = bdrv_attach_child(data->parent_b, data->c, "PB-C", 1161 &child_of_bds, BDRV_CHILD_DATA, 1162 &error_abort); 1163 bdrv_graph_wrunlock(); 1164 } 1165 1166 static void coroutine_mixed_fn 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 aio_bh_schedule_oneshot(qemu_get_current_aio_context(), 1174 detach_indirect_bh, &detach_by_parent_data); 1175 } 1176 } 1177 1178 static void GRAPH_RDLOCK detach_by_driver_cb_drained_begin(BdrvChild *child) 1179 { 1180 struct detach_by_parent_data *data = &detach_by_parent_data; 1181 1182 if (!data->detach_on_drain) { 1183 return; 1184 } 1185 data->detach_on_drain = false; 1186 1187 bdrv_inc_in_flight(data->child_b->bs); 1188 aio_bh_schedule_oneshot(qemu_get_current_aio_context(), 1189 detach_indirect_bh, &detach_by_parent_data); 1190 child_of_bds.drained_begin(child); 1191 } 1192 1193 static BdrvChildClass detach_by_driver_cb_class; 1194 1195 /* 1196 * Initial graph: 1197 * 1198 * PA PB 1199 * \ / \ 1200 * A B C 1201 * 1202 * by_parent_cb == true: Test that parent callbacks don't poll 1203 * 1204 * PA has a pending write request whose callback changes the child nodes of 1205 * PB: It removes B and adds C instead. The subtree of PB is drained, which 1206 * will indirectly drain the write request, too. 1207 * 1208 * by_parent_cb == false: Test that bdrv_drain_invoke() doesn't poll 1209 * 1210 * PA's BdrvChildClass has a .drained_begin callback that schedules a BH 1211 * that does the same graph change. If bdrv_drain_invoke() calls it, the 1212 * state is messed up, but if it is only polled in the single 1213 * BDRV_POLL_WHILE() at the end of the drain, this should work fine. 1214 */ 1215 static void TSA_NO_TSA test_detach_indirect(bool by_parent_cb) 1216 { 1217 BlockBackend *blk; 1218 BlockDriverState *parent_a, *parent_b, *a, *b, *c; 1219 BdrvChild *child_a, *child_b; 1220 BlockAIOCB *acb; 1221 1222 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 1223 1224 if (!by_parent_cb) { 1225 detach_by_driver_cb_class = child_of_bds; 1226 detach_by_driver_cb_class.drained_begin = 1227 detach_by_driver_cb_drained_begin; 1228 detach_by_driver_cb_class.drained_end = NULL; 1229 detach_by_driver_cb_class.drained_poll = NULL; 1230 } 1231 1232 detach_by_parent_data = (struct detach_by_parent_data) { 1233 .detach_on_drain = false, 1234 }; 1235 1236 /* Create all involved nodes */ 1237 parent_a = bdrv_new_open_driver(&bdrv_test, "parent-a", BDRV_O_RDWR, 1238 &error_abort); 1239 parent_b = bdrv_new_open_driver(&bdrv_test, "parent-b", 0, 1240 &error_abort); 1241 1242 a = bdrv_new_open_driver(&bdrv_test, "a", BDRV_O_RDWR, &error_abort); 1243 b = bdrv_new_open_driver(&bdrv_test, "b", BDRV_O_RDWR, &error_abort); 1244 c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort); 1245 1246 /* blk is a BB for parent-a */ 1247 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1248 blk_insert_bs(blk, parent_a, &error_abort); 1249 bdrv_unref(parent_a); 1250 1251 /* If we want to get bdrv_drain_invoke() to call aio_poll(), the driver 1252 * callback must not return immediately. */ 1253 if (!by_parent_cb) { 1254 BDRVTestState *s = parent_a->opaque; 1255 s->sleep_in_drain_begin = true; 1256 } 1257 1258 /* Set child relationships */ 1259 bdrv_ref(b); 1260 bdrv_ref(a); 1261 bdrv_graph_wrlock(); 1262 child_b = bdrv_attach_child(parent_b, b, "PB-B", &child_of_bds, 1263 BDRV_CHILD_DATA, &error_abort); 1264 child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_of_bds, 1265 BDRV_CHILD_COW, &error_abort); 1266 1267 bdrv_ref(a); 1268 bdrv_attach_child(parent_a, a, "PA-A", 1269 by_parent_cb ? &child_of_bds : &detach_by_driver_cb_class, 1270 BDRV_CHILD_DATA, &error_abort); 1271 bdrv_graph_wrunlock(); 1272 1273 g_assert_cmpint(parent_a->refcnt, ==, 1); 1274 g_assert_cmpint(parent_b->refcnt, ==, 1); 1275 g_assert_cmpint(a->refcnt, ==, 3); 1276 g_assert_cmpint(b->refcnt, ==, 2); 1277 g_assert_cmpint(c->refcnt, ==, 1); 1278 1279 g_assert(QLIST_FIRST(&parent_b->children) == child_a); 1280 g_assert(QLIST_NEXT(child_a, next) == child_b); 1281 g_assert(QLIST_NEXT(child_b, next) == NULL); 1282 1283 /* Start the evil write request */ 1284 detach_by_parent_data = (struct detach_by_parent_data) { 1285 .parent_b = parent_b, 1286 .child_b = child_b, 1287 .c = c, 1288 .by_parent_cb = by_parent_cb, 1289 .detach_on_drain = true, 1290 }; 1291 acb = blk_aio_preadv(blk, 0, &qiov, 0, detach_by_parent_aio_cb, NULL); 1292 g_assert(acb != NULL); 1293 1294 /* Drain and check the expected result */ 1295 bdrv_drained_begin(parent_b); 1296 bdrv_drained_begin(a); 1297 bdrv_drained_begin(b); 1298 bdrv_drained_begin(c); 1299 1300 g_assert(detach_by_parent_data.child_c != NULL); 1301 1302 g_assert_cmpint(parent_a->refcnt, ==, 1); 1303 g_assert_cmpint(parent_b->refcnt, ==, 1); 1304 g_assert_cmpint(a->refcnt, ==, 3); 1305 g_assert_cmpint(b->refcnt, ==, 1); 1306 g_assert_cmpint(c->refcnt, ==, 2); 1307 1308 g_assert(QLIST_FIRST(&parent_b->children) == detach_by_parent_data.child_c); 1309 g_assert(QLIST_NEXT(detach_by_parent_data.child_c, next) == child_a); 1310 g_assert(QLIST_NEXT(child_a, next) == NULL); 1311 1312 g_assert_cmpint(parent_a->quiesce_counter, ==, 1); 1313 g_assert_cmpint(parent_b->quiesce_counter, ==, 3); 1314 g_assert_cmpint(a->quiesce_counter, ==, 1); 1315 g_assert_cmpint(b->quiesce_counter, ==, 1); 1316 g_assert_cmpint(c->quiesce_counter, ==, 1); 1317 1318 bdrv_drained_end(parent_b); 1319 bdrv_drained_end(a); 1320 bdrv_drained_end(b); 1321 bdrv_drained_end(c); 1322 1323 bdrv_unref(parent_b); 1324 blk_unref(blk); 1325 1326 g_assert_cmpint(a->refcnt, ==, 1); 1327 g_assert_cmpint(b->refcnt, ==, 1); 1328 g_assert_cmpint(c->refcnt, ==, 1); 1329 bdrv_unref(a); 1330 bdrv_unref(b); 1331 bdrv_unref(c); 1332 } 1333 1334 static void test_detach_by_parent_cb(void) 1335 { 1336 test_detach_indirect(true); 1337 } 1338 1339 static void test_detach_by_driver_cb(void) 1340 { 1341 test_detach_indirect(false); 1342 } 1343 1344 static void test_append_to_drained(void) 1345 { 1346 BlockBackend *blk; 1347 BlockDriverState *base, *overlay; 1348 BDRVTestState *base_s, *overlay_s; 1349 1350 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1351 base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort); 1352 base_s = base->opaque; 1353 blk_insert_bs(blk, base, &error_abort); 1354 1355 overlay = bdrv_new_open_driver(&bdrv_test, "overlay", BDRV_O_RDWR, 1356 &error_abort); 1357 overlay_s = overlay->opaque; 1358 1359 do_drain_begin(BDRV_DRAIN, base); 1360 g_assert_cmpint(base->quiesce_counter, ==, 1); 1361 g_assert_cmpint(base_s->drain_count, ==, 1); 1362 g_assert_cmpint(base->in_flight, ==, 0); 1363 1364 bdrv_append(overlay, base, &error_abort); 1365 1366 g_assert_cmpint(base->in_flight, ==, 0); 1367 g_assert_cmpint(overlay->in_flight, ==, 0); 1368 1369 g_assert_cmpint(base->quiesce_counter, ==, 1); 1370 g_assert_cmpint(base_s->drain_count, ==, 1); 1371 g_assert_cmpint(overlay->quiesce_counter, ==, 1); 1372 g_assert_cmpint(overlay_s->drain_count, ==, 1); 1373 1374 do_drain_end(BDRV_DRAIN, base); 1375 1376 g_assert_cmpint(base->quiesce_counter, ==, 0); 1377 g_assert_cmpint(base_s->drain_count, ==, 0); 1378 g_assert_cmpint(overlay->quiesce_counter, ==, 0); 1379 g_assert_cmpint(overlay_s->drain_count, ==, 0); 1380 1381 bdrv_unref(overlay); 1382 bdrv_unref(base); 1383 blk_unref(blk); 1384 } 1385 1386 static void test_set_aio_context(void) 1387 { 1388 BlockDriverState *bs; 1389 IOThread *a = iothread_new(); 1390 IOThread *b = iothread_new(); 1391 AioContext *ctx_a = iothread_get_aio_context(a); 1392 AioContext *ctx_b = iothread_get_aio_context(b); 1393 1394 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 1395 &error_abort); 1396 1397 bdrv_drained_begin(bs); 1398 bdrv_try_change_aio_context(bs, ctx_a, NULL, &error_abort); 1399 bdrv_drained_end(bs); 1400 1401 bdrv_drained_begin(bs); 1402 bdrv_try_change_aio_context(bs, ctx_b, NULL, &error_abort); 1403 bdrv_try_change_aio_context(bs, qemu_get_aio_context(), NULL, &error_abort); 1404 bdrv_drained_end(bs); 1405 1406 bdrv_unref(bs); 1407 iothread_join(a); 1408 iothread_join(b); 1409 } 1410 1411 1412 typedef struct TestDropBackingBlockJob { 1413 BlockJob common; 1414 bool should_complete; 1415 bool *did_complete; 1416 BlockDriverState *detach_also; 1417 BlockDriverState *bs; 1418 } TestDropBackingBlockJob; 1419 1420 static int coroutine_fn test_drop_backing_job_run(Job *job, Error **errp) 1421 { 1422 TestDropBackingBlockJob *s = 1423 container_of(job, TestDropBackingBlockJob, common.job); 1424 1425 while (!s->should_complete) { 1426 job_sleep_ns(job, 0); 1427 } 1428 1429 return 0; 1430 } 1431 1432 static void test_drop_backing_job_commit(Job *job) 1433 { 1434 TestDropBackingBlockJob *s = 1435 container_of(job, TestDropBackingBlockJob, common.job); 1436 1437 bdrv_set_backing_hd(s->bs, NULL, &error_abort); 1438 bdrv_set_backing_hd(s->detach_also, NULL, &error_abort); 1439 1440 *s->did_complete = true; 1441 } 1442 1443 static const BlockJobDriver test_drop_backing_job_driver = { 1444 .job_driver = { 1445 .instance_size = sizeof(TestDropBackingBlockJob), 1446 .free = block_job_free, 1447 .user_resume = block_job_user_resume, 1448 .run = test_drop_backing_job_run, 1449 .commit = test_drop_backing_job_commit, 1450 } 1451 }; 1452 1453 /** 1454 * Creates a child node with three parent nodes on it, and then runs a 1455 * block job on the final one, parent-node-2. 1456 * 1457 * The job is then asked to complete before a section where the child 1458 * is drained. 1459 * 1460 * Ending this section will undrain the child's parents, first 1461 * parent-node-2, then parent-node-1, then parent-node-0 -- the parent 1462 * list is in reverse order of how they were added. Ending the drain 1463 * on parent-node-2 will resume the job, thus completing it and 1464 * scheduling job_exit(). 1465 * 1466 * Ending the drain on parent-node-1 will poll the AioContext, which 1467 * lets job_exit() and thus test_drop_backing_job_commit() run. That 1468 * function first removes the child as parent-node-2's backing file. 1469 * 1470 * In old (and buggy) implementations, there are two problems with 1471 * that: 1472 * (A) bdrv_drain_invoke() polls for every node that leaves the 1473 * drained section. This means that job_exit() is scheduled 1474 * before the child has left the drained section. Its 1475 * quiesce_counter is therefore still 1 when it is removed from 1476 * parent-node-2. 1477 * 1478 * (B) bdrv_replace_child_noperm() calls drained_end() on the old 1479 * child's parents as many times as the child is quiesced. This 1480 * means it will call drained_end() on parent-node-2 once. 1481 * Because parent-node-2 is no longer quiesced at this point, this 1482 * will fail. 1483 * 1484 * bdrv_replace_child_noperm() therefore must call drained_end() on 1485 * the parent only if it really is still drained because the child is 1486 * drained. 1487 * 1488 * If removing child from parent-node-2 was successful (as it should 1489 * be), test_drop_backing_job_commit() will then also remove the child 1490 * from parent-node-0. 1491 * 1492 * With an old version of our drain infrastructure ((A) above), that 1493 * resulted in the following flow: 1494 * 1495 * 1. child attempts to leave its drained section. The call recurses 1496 * to its parents. 1497 * 1498 * 2. parent-node-2 leaves the drained section. Polling in 1499 * bdrv_drain_invoke() will schedule job_exit(). 1500 * 1501 * 3. parent-node-1 leaves the drained section. Polling in 1502 * bdrv_drain_invoke() will run job_exit(), thus disconnecting 1503 * parent-node-0 from the child node. 1504 * 1505 * 4. bdrv_parent_drained_end() uses a QLIST_FOREACH_SAFE() loop to 1506 * iterate over the parents. Thus, it now accesses the BdrvChild 1507 * object that used to connect parent-node-0 and the child node. 1508 * However, that object no longer exists, so it accesses a dangling 1509 * pointer. 1510 * 1511 * The solution is to only poll once when running a bdrv_drained_end() 1512 * operation, specifically at the end when all drained_end() 1513 * operations for all involved nodes have been scheduled. 1514 * Note that this also solves (A) above, thus hiding (B). 1515 */ 1516 static void test_blockjob_commit_by_drained_end(void) 1517 { 1518 BlockDriverState *bs_child, *bs_parents[3]; 1519 TestDropBackingBlockJob *job; 1520 bool job_has_completed = false; 1521 int i; 1522 1523 bs_child = bdrv_new_open_driver(&bdrv_test, "child-node", BDRV_O_RDWR, 1524 &error_abort); 1525 1526 for (i = 0; i < 3; i++) { 1527 char name[32]; 1528 snprintf(name, sizeof(name), "parent-node-%i", i); 1529 bs_parents[i] = bdrv_new_open_driver(&bdrv_test, name, BDRV_O_RDWR, 1530 &error_abort); 1531 bdrv_set_backing_hd(bs_parents[i], bs_child, &error_abort); 1532 } 1533 1534 job = block_job_create("job", &test_drop_backing_job_driver, NULL, 1535 bs_parents[2], 0, BLK_PERM_ALL, 0, 0, NULL, NULL, 1536 &error_abort); 1537 job->bs = bs_parents[2]; 1538 1539 job->detach_also = bs_parents[0]; 1540 job->did_complete = &job_has_completed; 1541 1542 job_start(&job->common.job); 1543 1544 job->should_complete = true; 1545 bdrv_drained_begin(bs_child); 1546 g_assert(!job_has_completed); 1547 bdrv_drained_end(bs_child); 1548 aio_poll(qemu_get_aio_context(), false); 1549 g_assert(job_has_completed); 1550 1551 bdrv_unref(bs_parents[0]); 1552 bdrv_unref(bs_parents[1]); 1553 bdrv_unref(bs_parents[2]); 1554 bdrv_unref(bs_child); 1555 } 1556 1557 1558 typedef struct TestSimpleBlockJob { 1559 BlockJob common; 1560 bool should_complete; 1561 bool *did_complete; 1562 } TestSimpleBlockJob; 1563 1564 static int coroutine_fn test_simple_job_run(Job *job, Error **errp) 1565 { 1566 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1567 1568 while (!s->should_complete) { 1569 job_sleep_ns(job, 0); 1570 } 1571 1572 return 0; 1573 } 1574 1575 static void test_simple_job_clean(Job *job) 1576 { 1577 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1578 *s->did_complete = true; 1579 } 1580 1581 static const BlockJobDriver test_simple_job_driver = { 1582 .job_driver = { 1583 .instance_size = sizeof(TestSimpleBlockJob), 1584 .free = block_job_free, 1585 .user_resume = block_job_user_resume, 1586 .run = test_simple_job_run, 1587 .clean = test_simple_job_clean, 1588 }, 1589 }; 1590 1591 static int drop_intermediate_poll_update_filename(BdrvChild *child, 1592 BlockDriverState *new_base, 1593 const char *filename, 1594 bool backing_mask_protocol, 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 bdrv_graph_wrlock(); 1685 for (i = 0; i < 3; i++) { 1686 if (i) { 1687 /* Takes the reference to chain[i - 1] */ 1688 bdrv_attach_child(chain[i], chain[i - 1], "chain", 1689 &chain_child_class, BDRV_CHILD_COW, &error_abort); 1690 } 1691 } 1692 bdrv_graph_wrunlock(); 1693 1694 job = block_job_create("job", &test_simple_job_driver, NULL, job_node, 1695 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort); 1696 1697 /* The job has a reference now */ 1698 bdrv_unref(job_node); 1699 1700 job->did_complete = &job_has_completed; 1701 1702 job_start(&job->common.job); 1703 job->should_complete = true; 1704 1705 g_assert(!job_has_completed); 1706 ret = bdrv_drop_intermediate(chain[1], chain[0], NULL, false); 1707 aio_poll(qemu_get_aio_context(), false); 1708 g_assert(ret == 0); 1709 g_assert(job_has_completed); 1710 1711 bdrv_unref(chain[2]); 1712 } 1713 1714 1715 typedef struct BDRVReplaceTestState { 1716 bool setup_completed; 1717 bool was_drained; 1718 bool was_undrained; 1719 bool has_read; 1720 1721 int drain_count; 1722 1723 bool yield_before_read; 1724 Coroutine *io_co; 1725 Coroutine *drain_co; 1726 } BDRVReplaceTestState; 1727 1728 static void bdrv_replace_test_close(BlockDriverState *bs) 1729 { 1730 } 1731 1732 /** 1733 * If @bs has a backing file: 1734 * Yield if .yield_before_read is true (and wait for drain_begin to 1735 * wake us up). 1736 * Forward the read to bs->backing. Set .has_read to true. 1737 * If drain_begin has woken us, wake it in turn. 1738 * 1739 * Otherwise: 1740 * Set .has_read to true and return success. 1741 */ 1742 static int coroutine_fn GRAPH_RDLOCK 1743 bdrv_replace_test_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 1744 QEMUIOVector *qiov, BdrvRequestFlags flags) 1745 { 1746 BDRVReplaceTestState *s = bs->opaque; 1747 1748 if (bs->backing) { 1749 int ret; 1750 1751 g_assert(!s->drain_count); 1752 1753 s->io_co = qemu_coroutine_self(); 1754 if (s->yield_before_read) { 1755 s->yield_before_read = false; 1756 qemu_coroutine_yield(); 1757 } 1758 s->io_co = NULL; 1759 1760 ret = bdrv_co_preadv(bs->backing, offset, bytes, qiov, 0); 1761 s->has_read = true; 1762 1763 /* Wake up drain_co if it runs */ 1764 if (s->drain_co) { 1765 aio_co_wake(s->drain_co); 1766 } 1767 1768 return ret; 1769 } 1770 1771 s->has_read = true; 1772 return 0; 1773 } 1774 1775 static void coroutine_fn bdrv_replace_test_drain_co(void *opaque) 1776 { 1777 BlockDriverState *bs = opaque; 1778 BDRVReplaceTestState *s = bs->opaque; 1779 1780 /* Keep waking io_co up until it is done */ 1781 while (s->io_co) { 1782 aio_co_wake(s->io_co); 1783 s->io_co = NULL; 1784 qemu_coroutine_yield(); 1785 } 1786 s->drain_co = NULL; 1787 bdrv_dec_in_flight(bs); 1788 } 1789 1790 /** 1791 * If .drain_count is 0, wake up .io_co if there is one; and set 1792 * .was_drained. 1793 * Increment .drain_count. 1794 */ 1795 static void bdrv_replace_test_drain_begin(BlockDriverState *bs) 1796 { 1797 BDRVReplaceTestState *s = bs->opaque; 1798 1799 if (!s->setup_completed) { 1800 return; 1801 } 1802 1803 if (!s->drain_count) { 1804 s->drain_co = qemu_coroutine_create(bdrv_replace_test_drain_co, bs); 1805 bdrv_inc_in_flight(bs); 1806 aio_co_enter(bdrv_get_aio_context(bs), s->drain_co); 1807 s->was_drained = true; 1808 } 1809 s->drain_count++; 1810 } 1811 1812 static void coroutine_fn bdrv_replace_test_read_entry(void *opaque) 1813 { 1814 BlockDriverState *bs = opaque; 1815 char data; 1816 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); 1817 int ret; 1818 1819 /* Queue a read request post-drain */ 1820 bdrv_graph_co_rdlock(); 1821 ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); 1822 bdrv_graph_co_rdunlock(); 1823 1824 g_assert(ret >= 0); 1825 bdrv_dec_in_flight(bs); 1826 } 1827 1828 /** 1829 * Reduce .drain_count, set .was_undrained once it reaches 0. 1830 * If .drain_count reaches 0 and the node has a backing file, issue a 1831 * read request. 1832 */ 1833 static void bdrv_replace_test_drain_end(BlockDriverState *bs) 1834 { 1835 BDRVReplaceTestState *s = bs->opaque; 1836 1837 GRAPH_RDLOCK_GUARD_MAINLOOP(); 1838 1839 if (!s->setup_completed) { 1840 return; 1841 } 1842 1843 g_assert(s->drain_count > 0); 1844 if (!--s->drain_count) { 1845 s->was_undrained = true; 1846 1847 if (bs->backing) { 1848 Coroutine *co = qemu_coroutine_create(bdrv_replace_test_read_entry, 1849 bs); 1850 bdrv_inc_in_flight(bs); 1851 aio_co_enter(bdrv_get_aio_context(bs), co); 1852 } 1853 } 1854 } 1855 1856 static BlockDriver bdrv_replace_test = { 1857 .format_name = "replace_test", 1858 .instance_size = sizeof(BDRVReplaceTestState), 1859 .supports_backing = true, 1860 1861 .bdrv_close = bdrv_replace_test_close, 1862 .bdrv_co_preadv = bdrv_replace_test_co_preadv, 1863 1864 .bdrv_drain_begin = bdrv_replace_test_drain_begin, 1865 .bdrv_drain_end = bdrv_replace_test_drain_end, 1866 1867 .bdrv_child_perm = bdrv_default_perms, 1868 }; 1869 1870 static void coroutine_fn test_replace_child_mid_drain_read_co(void *opaque) 1871 { 1872 int ret; 1873 char data; 1874 1875 ret = blk_co_pread(opaque, 0, 1, &data, 0); 1876 g_assert(ret >= 0); 1877 } 1878 1879 /** 1880 * We test two things: 1881 * (1) bdrv_replace_child_noperm() must not undrain the parent if both 1882 * children are drained. 1883 * (2) bdrv_replace_child_noperm() must never flush I/O requests to a 1884 * drained child. If the old child is drained, it must flush I/O 1885 * requests after the new one has been attached. If the new child 1886 * is drained, it must flush I/O requests before the old one is 1887 * detached. 1888 * 1889 * To do so, we create one parent node and two child nodes; then 1890 * attach one of the children (old_child_bs) to the parent, then 1891 * drain both old_child_bs and new_child_bs according to 1892 * old_drain_count and new_drain_count, respectively, and finally 1893 * we invoke bdrv_replace_node() to replace old_child_bs by 1894 * new_child_bs. 1895 * 1896 * The test block driver we use here (bdrv_replace_test) has a read 1897 * function that: 1898 * - For the parent node, can optionally yield, and then forwards the 1899 * read to bdrv_preadv(), 1900 * - For the child node, just returns immediately. 1901 * 1902 * If the read yields, the drain_begin function will wake it up. 1903 * 1904 * The drain_end function issues a read on the parent once it is fully 1905 * undrained (which simulates requests starting to come in again). 1906 */ 1907 static void do_test_replace_child_mid_drain(int old_drain_count, 1908 int new_drain_count) 1909 { 1910 BlockBackend *parent_blk; 1911 BlockDriverState *parent_bs; 1912 BlockDriverState *old_child_bs, *new_child_bs; 1913 BDRVReplaceTestState *parent_s; 1914 BDRVReplaceTestState *old_child_s, *new_child_s; 1915 Coroutine *io_co; 1916 int i; 1917 1918 parent_bs = bdrv_new_open_driver(&bdrv_replace_test, "parent", 0, 1919 &error_abort); 1920 parent_s = parent_bs->opaque; 1921 1922 parent_blk = blk_new(qemu_get_aio_context(), 1923 BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL); 1924 blk_insert_bs(parent_blk, parent_bs, &error_abort); 1925 1926 old_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "old-child", 0, 1927 &error_abort); 1928 new_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "new-child", 0, 1929 &error_abort); 1930 old_child_s = old_child_bs->opaque; 1931 new_child_s = new_child_bs->opaque; 1932 1933 /* So that we can read something */ 1934 parent_bs->total_sectors = 1; 1935 old_child_bs->total_sectors = 1; 1936 new_child_bs->total_sectors = 1; 1937 1938 bdrv_ref(old_child_bs); 1939 bdrv_graph_wrlock(); 1940 bdrv_attach_child(parent_bs, old_child_bs, "child", &child_of_bds, 1941 BDRV_CHILD_COW, &error_abort); 1942 bdrv_graph_wrunlock(); 1943 parent_s->setup_completed = true; 1944 1945 for (i = 0; i < old_drain_count; i++) { 1946 bdrv_drained_begin(old_child_bs); 1947 } 1948 for (i = 0; i < new_drain_count; i++) { 1949 bdrv_drained_begin(new_child_bs); 1950 } 1951 1952 if (!old_drain_count) { 1953 /* 1954 * Start a read operation that will yield, so it will not 1955 * complete before the node is drained. 1956 */ 1957 parent_s->yield_before_read = true; 1958 io_co = qemu_coroutine_create(test_replace_child_mid_drain_read_co, 1959 parent_blk); 1960 qemu_coroutine_enter(io_co); 1961 } 1962 1963 /* If we have started a read operation, it should have yielded */ 1964 g_assert(!parent_s->has_read); 1965 1966 /* Reset drained status so we can see what bdrv_replace_node() does */ 1967 parent_s->was_drained = false; 1968 parent_s->was_undrained = false; 1969 1970 g_assert(parent_bs->quiesce_counter == old_drain_count); 1971 bdrv_drained_begin(old_child_bs); 1972 bdrv_drained_begin(new_child_bs); 1973 bdrv_graph_wrlock(); 1974 bdrv_replace_node(old_child_bs, new_child_bs, &error_abort); 1975 bdrv_graph_wrunlock(); 1976 bdrv_drained_end(new_child_bs); 1977 bdrv_drained_end(old_child_bs); 1978 g_assert(parent_bs->quiesce_counter == new_drain_count); 1979 1980 if (!old_drain_count && !new_drain_count) { 1981 /* 1982 * From undrained to undrained drains and undrains the parent, 1983 * because bdrv_replace_node() contains a drained section for 1984 * @old_child_bs. 1985 */ 1986 g_assert(parent_s->was_drained && parent_s->was_undrained); 1987 } else if (!old_drain_count && new_drain_count) { 1988 /* 1989 * From undrained to drained should drain the parent and keep 1990 * it that way. 1991 */ 1992 g_assert(parent_s->was_drained && !parent_s->was_undrained); 1993 } else if (old_drain_count && !new_drain_count) { 1994 /* 1995 * From drained to undrained should undrain the parent and 1996 * keep it that way. 1997 */ 1998 g_assert(!parent_s->was_drained && parent_s->was_undrained); 1999 } else /* if (old_drain_count && new_drain_count) */ { 2000 /* 2001 * From drained to drained must not undrain the parent at any 2002 * point 2003 */ 2004 g_assert(!parent_s->was_drained && !parent_s->was_undrained); 2005 } 2006 2007 if (!old_drain_count || !new_drain_count) { 2008 /* 2009 * If !old_drain_count, we have started a read request before 2010 * bdrv_replace_node(). If !new_drain_count, the parent must 2011 * have been undrained at some point, and 2012 * bdrv_replace_test_co_drain_end() starts a read request 2013 * then. 2014 */ 2015 g_assert(parent_s->has_read); 2016 } else { 2017 /* 2018 * If the parent was never undrained, there is no way to start 2019 * a read request. 2020 */ 2021 g_assert(!parent_s->has_read); 2022 } 2023 2024 /* A drained child must have not received any request */ 2025 g_assert(!(old_drain_count && old_child_s->has_read)); 2026 g_assert(!(new_drain_count && new_child_s->has_read)); 2027 2028 for (i = 0; i < new_drain_count; i++) { 2029 bdrv_drained_end(new_child_bs); 2030 } 2031 for (i = 0; i < old_drain_count; i++) { 2032 bdrv_drained_end(old_child_bs); 2033 } 2034 2035 /* 2036 * By now, bdrv_replace_test_co_drain_end() must have been called 2037 * at some point while the new child was attached to the parent. 2038 */ 2039 g_assert(parent_s->has_read); 2040 g_assert(new_child_s->has_read); 2041 2042 blk_unref(parent_blk); 2043 bdrv_unref(parent_bs); 2044 bdrv_unref(old_child_bs); 2045 bdrv_unref(new_child_bs); 2046 } 2047 2048 static void test_replace_child_mid_drain(void) 2049 { 2050 int old_drain_count, new_drain_count; 2051 2052 for (old_drain_count = 0; old_drain_count < 2; old_drain_count++) { 2053 for (new_drain_count = 0; new_drain_count < 2; new_drain_count++) { 2054 do_test_replace_child_mid_drain(old_drain_count, new_drain_count); 2055 } 2056 } 2057 } 2058 2059 int main(int argc, char **argv) 2060 { 2061 int ret; 2062 2063 bdrv_init(); 2064 qemu_init_main_loop(&error_abort); 2065 2066 g_test_init(&argc, &argv, NULL); 2067 qemu_event_init(&done_event, false); 2068 2069 g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all); 2070 g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain); 2071 2072 g_test_add_func("/bdrv-drain/driver-cb/co/drain_all", 2073 test_drv_cb_co_drain_all); 2074 g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain); 2075 2076 g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all); 2077 g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain); 2078 2079 g_test_add_func("/bdrv-drain/quiesce/co/drain_all", 2080 test_quiesce_co_drain_all); 2081 g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain); 2082 2083 g_test_add_func("/bdrv-drain/nested", test_nested); 2084 2085 g_test_add_func("/bdrv-drain/graph-change/drain_all", 2086 test_graph_change_drain_all); 2087 2088 g_test_add_func("/bdrv-drain/iothread/drain_all", test_iothread_drain_all); 2089 g_test_add_func("/bdrv-drain/iothread/drain", test_iothread_drain); 2090 2091 g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all); 2092 g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain); 2093 2094 g_test_add_func("/bdrv-drain/blockjob/error/drain_all", 2095 test_blockjob_error_drain_all); 2096 g_test_add_func("/bdrv-drain/blockjob/error/drain", 2097 test_blockjob_error_drain); 2098 2099 g_test_add_func("/bdrv-drain/blockjob/iothread/drain_all", 2100 test_blockjob_iothread_drain_all); 2101 g_test_add_func("/bdrv-drain/blockjob/iothread/drain", 2102 test_blockjob_iothread_drain); 2103 2104 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_all", 2105 test_blockjob_iothread_error_drain_all); 2106 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain", 2107 test_blockjob_iothread_error_drain); 2108 2109 g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain); 2110 g_test_add_func("/bdrv-drain/detach/drain_all", test_detach_by_drain_all); 2111 g_test_add_func("/bdrv-drain/detach/drain", test_detach_by_drain); 2112 g_test_add_func("/bdrv-drain/detach/parent_cb", test_detach_by_parent_cb); 2113 g_test_add_func("/bdrv-drain/detach/driver_cb", test_detach_by_driver_cb); 2114 2115 g_test_add_func("/bdrv-drain/attach/drain", test_append_to_drained); 2116 2117 g_test_add_func("/bdrv-drain/set_aio_context", test_set_aio_context); 2118 2119 g_test_add_func("/bdrv-drain/blockjob/commit_by_drained_end", 2120 test_blockjob_commit_by_drained_end); 2121 2122 g_test_add_func("/bdrv-drain/bdrv_drop_intermediate/poll", 2123 test_drop_intermediate_poll); 2124 2125 g_test_add_func("/bdrv-drain/replace_child/mid-drain", 2126 test_replace_child_mid_drain); 2127 2128 ret = g_test_run(); 2129 qemu_event_destroy(&done_event); 2130 return ret; 2131 } 2132