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.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 bdrv_test_co_drain_begin(BlockDriverState *bs) 42 { 43 BDRVTestState *s = bs->opaque; 44 s->drain_count++; 45 if (s->sleep_in_drain_begin) { 46 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000); 47 } 48 } 49 50 static void coroutine_fn bdrv_test_co_drain_end(BlockDriverState *bs) 51 { 52 BDRVTestState *s = bs->opaque; 53 s->drain_count--; 54 } 55 56 static void bdrv_test_close(BlockDriverState *bs) 57 { 58 BDRVTestState *s = bs->opaque; 59 g_assert_cmpint(s->drain_count, >, 0); 60 } 61 62 static void co_reenter_bh(void *opaque) 63 { 64 aio_co_wake(opaque); 65 } 66 67 static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs, 68 int64_t offset, int64_t bytes, 69 QEMUIOVector *qiov, 70 BdrvRequestFlags flags) 71 { 72 BDRVTestState *s = bs->opaque; 73 74 /* We want this request to stay until the polling loop in drain waits for 75 * it to complete. We need to sleep a while as bdrv_drain_invoke() comes 76 * first and polls its result, too, but it shouldn't accidentally complete 77 * this request yet. */ 78 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000); 79 80 if (s->bh_indirection_ctx) { 81 aio_bh_schedule_oneshot(s->bh_indirection_ctx, co_reenter_bh, 82 qemu_coroutine_self()); 83 qemu_coroutine_yield(); 84 } 85 86 return 0; 87 } 88 89 static int bdrv_test_change_backing_file(BlockDriverState *bs, 90 const char *backing_file, 91 const char *backing_fmt) 92 { 93 return 0; 94 } 95 96 static BlockDriver bdrv_test = { 97 .format_name = "test", 98 .instance_size = sizeof(BDRVTestState), 99 .supports_backing = true, 100 101 .bdrv_close = bdrv_test_close, 102 .bdrv_co_preadv = bdrv_test_co_preadv, 103 104 .bdrv_co_drain_begin = bdrv_test_co_drain_begin, 105 .bdrv_co_drain_end = bdrv_test_co_drain_end, 106 107 .bdrv_child_perm = bdrv_default_perms, 108 109 .bdrv_change_backing_file = bdrv_test_change_backing_file, 110 }; 111 112 static void aio_ret_cb(void *opaque, int ret) 113 { 114 int *aio_ret = opaque; 115 *aio_ret = ret; 116 } 117 118 typedef struct CallInCoroutineData { 119 void (*entry)(void); 120 bool done; 121 } CallInCoroutineData; 122 123 static coroutine_fn void call_in_coroutine_entry(void *opaque) 124 { 125 CallInCoroutineData *data = opaque; 126 127 data->entry(); 128 data->done = true; 129 } 130 131 static void call_in_coroutine(void (*entry)(void)) 132 { 133 Coroutine *co; 134 CallInCoroutineData data = { 135 .entry = entry, 136 .done = false, 137 }; 138 139 co = qemu_coroutine_create(call_in_coroutine_entry, &data); 140 qemu_coroutine_enter(co); 141 while (!data.done) { 142 aio_poll(qemu_get_aio_context(), true); 143 } 144 } 145 146 enum drain_type { 147 BDRV_DRAIN_ALL, 148 BDRV_DRAIN, 149 BDRV_SUBTREE_DRAIN, 150 DRAIN_TYPE_MAX, 151 }; 152 153 static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs) 154 { 155 switch (drain_type) { 156 case BDRV_DRAIN_ALL: bdrv_drain_all_begin(); break; 157 case BDRV_DRAIN: bdrv_drained_begin(bs); break; 158 case BDRV_SUBTREE_DRAIN: bdrv_subtree_drained_begin(bs); break; 159 default: g_assert_not_reached(); 160 } 161 } 162 163 static void do_drain_end(enum drain_type drain_type, BlockDriverState *bs) 164 { 165 switch (drain_type) { 166 case BDRV_DRAIN_ALL: bdrv_drain_all_end(); break; 167 case BDRV_DRAIN: bdrv_drained_end(bs); break; 168 case BDRV_SUBTREE_DRAIN: bdrv_subtree_drained_end(bs); break; 169 default: g_assert_not_reached(); 170 } 171 } 172 173 static void do_drain_begin_unlocked(enum drain_type drain_type, BlockDriverState *bs) 174 { 175 if (drain_type != BDRV_DRAIN_ALL) { 176 aio_context_acquire(bdrv_get_aio_context(bs)); 177 } 178 do_drain_begin(drain_type, bs); 179 if (drain_type != BDRV_DRAIN_ALL) { 180 aio_context_release(bdrv_get_aio_context(bs)); 181 } 182 } 183 184 static void do_drain_end_unlocked(enum drain_type drain_type, BlockDriverState *bs) 185 { 186 if (drain_type != BDRV_DRAIN_ALL) { 187 aio_context_acquire(bdrv_get_aio_context(bs)); 188 } 189 do_drain_end(drain_type, bs); 190 if (drain_type != BDRV_DRAIN_ALL) { 191 aio_context_release(bdrv_get_aio_context(bs)); 192 } 193 } 194 195 static void test_drv_cb_common(enum drain_type drain_type, bool recursive) 196 { 197 BlockBackend *blk; 198 BlockDriverState *bs, *backing; 199 BDRVTestState *s, *backing_s; 200 BlockAIOCB *acb; 201 int aio_ret; 202 203 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 204 205 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 206 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 207 &error_abort); 208 s = bs->opaque; 209 blk_insert_bs(blk, bs, &error_abort); 210 211 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 212 backing_s = backing->opaque; 213 bdrv_set_backing_hd(bs, backing, &error_abort); 214 215 /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */ 216 g_assert_cmpint(s->drain_count, ==, 0); 217 g_assert_cmpint(backing_s->drain_count, ==, 0); 218 219 do_drain_begin(drain_type, bs); 220 221 g_assert_cmpint(s->drain_count, ==, 1); 222 g_assert_cmpint(backing_s->drain_count, ==, !!recursive); 223 224 do_drain_end(drain_type, bs); 225 226 g_assert_cmpint(s->drain_count, ==, 0); 227 g_assert_cmpint(backing_s->drain_count, ==, 0); 228 229 /* Now do the same while a request is pending */ 230 aio_ret = -EINPROGRESS; 231 acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); 232 g_assert(acb != NULL); 233 g_assert_cmpint(aio_ret, ==, -EINPROGRESS); 234 235 g_assert_cmpint(s->drain_count, ==, 0); 236 g_assert_cmpint(backing_s->drain_count, ==, 0); 237 238 do_drain_begin(drain_type, bs); 239 240 g_assert_cmpint(aio_ret, ==, 0); 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 bdrv_unref(backing); 250 bdrv_unref(bs); 251 blk_unref(blk); 252 } 253 254 static void test_drv_cb_drain_all(void) 255 { 256 test_drv_cb_common(BDRV_DRAIN_ALL, true); 257 } 258 259 static void test_drv_cb_drain(void) 260 { 261 test_drv_cb_common(BDRV_DRAIN, false); 262 } 263 264 static void test_drv_cb_drain_subtree(void) 265 { 266 test_drv_cb_common(BDRV_SUBTREE_DRAIN, true); 267 } 268 269 static void test_drv_cb_co_drain_all(void) 270 { 271 call_in_coroutine(test_drv_cb_drain_all); 272 } 273 274 static void test_drv_cb_co_drain(void) 275 { 276 call_in_coroutine(test_drv_cb_drain); 277 } 278 279 static void test_drv_cb_co_drain_subtree(void) 280 { 281 call_in_coroutine(test_drv_cb_drain_subtree); 282 } 283 284 static void test_quiesce_common(enum drain_type drain_type, bool recursive) 285 { 286 BlockBackend *blk; 287 BlockDriverState *bs, *backing; 288 289 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 290 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 291 &error_abort); 292 blk_insert_bs(blk, bs, &error_abort); 293 294 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 295 bdrv_set_backing_hd(bs, backing, &error_abort); 296 297 g_assert_cmpint(bs->quiesce_counter, ==, 0); 298 g_assert_cmpint(backing->quiesce_counter, ==, 0); 299 300 do_drain_begin(drain_type, bs); 301 302 g_assert_cmpint(bs->quiesce_counter, ==, 1); 303 g_assert_cmpint(backing->quiesce_counter, ==, !!recursive); 304 305 do_drain_end(drain_type, bs); 306 307 g_assert_cmpint(bs->quiesce_counter, ==, 0); 308 g_assert_cmpint(backing->quiesce_counter, ==, 0); 309 310 bdrv_unref(backing); 311 bdrv_unref(bs); 312 blk_unref(blk); 313 } 314 315 static void test_quiesce_drain_all(void) 316 { 317 test_quiesce_common(BDRV_DRAIN_ALL, true); 318 } 319 320 static void test_quiesce_drain(void) 321 { 322 test_quiesce_common(BDRV_DRAIN, false); 323 } 324 325 static void test_quiesce_drain_subtree(void) 326 { 327 test_quiesce_common(BDRV_SUBTREE_DRAIN, true); 328 } 329 330 static void test_quiesce_co_drain_all(void) 331 { 332 call_in_coroutine(test_quiesce_drain_all); 333 } 334 335 static void test_quiesce_co_drain(void) 336 { 337 call_in_coroutine(test_quiesce_drain); 338 } 339 340 static void test_quiesce_co_drain_subtree(void) 341 { 342 call_in_coroutine(test_quiesce_drain_subtree); 343 } 344 345 static void test_nested(void) 346 { 347 BlockBackend *blk; 348 BlockDriverState *bs, *backing; 349 BDRVTestState *s, *backing_s; 350 enum drain_type outer, inner; 351 352 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 353 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 354 &error_abort); 355 s = bs->opaque; 356 blk_insert_bs(blk, bs, &error_abort); 357 358 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 359 backing_s = backing->opaque; 360 bdrv_set_backing_hd(bs, backing, &error_abort); 361 362 for (outer = 0; outer < DRAIN_TYPE_MAX; outer++) { 363 for (inner = 0; inner < DRAIN_TYPE_MAX; inner++) { 364 int backing_quiesce = (outer != BDRV_DRAIN) + 365 (inner != BDRV_DRAIN); 366 367 g_assert_cmpint(bs->quiesce_counter, ==, 0); 368 g_assert_cmpint(backing->quiesce_counter, ==, 0); 369 g_assert_cmpint(s->drain_count, ==, 0); 370 g_assert_cmpint(backing_s->drain_count, ==, 0); 371 372 do_drain_begin(outer, bs); 373 do_drain_begin(inner, bs); 374 375 g_assert_cmpint(bs->quiesce_counter, ==, 2); 376 g_assert_cmpint(backing->quiesce_counter, ==, backing_quiesce); 377 g_assert_cmpint(s->drain_count, ==, 2); 378 g_assert_cmpint(backing_s->drain_count, ==, backing_quiesce); 379 380 do_drain_end(inner, bs); 381 do_drain_end(outer, bs); 382 383 g_assert_cmpint(bs->quiesce_counter, ==, 0); 384 g_assert_cmpint(backing->quiesce_counter, ==, 0); 385 g_assert_cmpint(s->drain_count, ==, 0); 386 g_assert_cmpint(backing_s->drain_count, ==, 0); 387 } 388 } 389 390 bdrv_unref(backing); 391 bdrv_unref(bs); 392 blk_unref(blk); 393 } 394 395 static void test_multiparent(void) 396 { 397 BlockBackend *blk_a, *blk_b; 398 BlockDriverState *bs_a, *bs_b, *backing; 399 BDRVTestState *a_s, *b_s, *backing_s; 400 401 blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 402 bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR, 403 &error_abort); 404 a_s = bs_a->opaque; 405 blk_insert_bs(blk_a, bs_a, &error_abort); 406 407 blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 408 bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR, 409 &error_abort); 410 b_s = bs_b->opaque; 411 blk_insert_bs(blk_b, bs_b, &error_abort); 412 413 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 414 backing_s = backing->opaque; 415 bdrv_set_backing_hd(bs_a, backing, &error_abort); 416 bdrv_set_backing_hd(bs_b, backing, &error_abort); 417 418 g_assert_cmpint(bs_a->quiesce_counter, ==, 0); 419 g_assert_cmpint(bs_b->quiesce_counter, ==, 0); 420 g_assert_cmpint(backing->quiesce_counter, ==, 0); 421 g_assert_cmpint(a_s->drain_count, ==, 0); 422 g_assert_cmpint(b_s->drain_count, ==, 0); 423 g_assert_cmpint(backing_s->drain_count, ==, 0); 424 425 do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); 426 427 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 428 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 429 g_assert_cmpint(backing->quiesce_counter, ==, 1); 430 g_assert_cmpint(a_s->drain_count, ==, 1); 431 g_assert_cmpint(b_s->drain_count, ==, 1); 432 g_assert_cmpint(backing_s->drain_count, ==, 1); 433 434 do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b); 435 436 g_assert_cmpint(bs_a->quiesce_counter, ==, 2); 437 g_assert_cmpint(bs_b->quiesce_counter, ==, 2); 438 g_assert_cmpint(backing->quiesce_counter, ==, 2); 439 g_assert_cmpint(a_s->drain_count, ==, 2); 440 g_assert_cmpint(b_s->drain_count, ==, 2); 441 g_assert_cmpint(backing_s->drain_count, ==, 2); 442 443 do_drain_end(BDRV_SUBTREE_DRAIN, bs_b); 444 445 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 446 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 447 g_assert_cmpint(backing->quiesce_counter, ==, 1); 448 g_assert_cmpint(a_s->drain_count, ==, 1); 449 g_assert_cmpint(b_s->drain_count, ==, 1); 450 g_assert_cmpint(backing_s->drain_count, ==, 1); 451 452 do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); 453 454 g_assert_cmpint(bs_a->quiesce_counter, ==, 0); 455 g_assert_cmpint(bs_b->quiesce_counter, ==, 0); 456 g_assert_cmpint(backing->quiesce_counter, ==, 0); 457 g_assert_cmpint(a_s->drain_count, ==, 0); 458 g_assert_cmpint(b_s->drain_count, ==, 0); 459 g_assert_cmpint(backing_s->drain_count, ==, 0); 460 461 bdrv_unref(backing); 462 bdrv_unref(bs_a); 463 bdrv_unref(bs_b); 464 blk_unref(blk_a); 465 blk_unref(blk_b); 466 } 467 468 static void test_graph_change_drain_subtree(void) 469 { 470 BlockBackend *blk_a, *blk_b; 471 BlockDriverState *bs_a, *bs_b, *backing; 472 BDRVTestState *a_s, *b_s, *backing_s; 473 474 blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 475 bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR, 476 &error_abort); 477 a_s = bs_a->opaque; 478 blk_insert_bs(blk_a, bs_a, &error_abort); 479 480 blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 481 bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR, 482 &error_abort); 483 b_s = bs_b->opaque; 484 blk_insert_bs(blk_b, bs_b, &error_abort); 485 486 backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); 487 backing_s = backing->opaque; 488 bdrv_set_backing_hd(bs_a, backing, &error_abort); 489 490 g_assert_cmpint(bs_a->quiesce_counter, ==, 0); 491 g_assert_cmpint(bs_b->quiesce_counter, ==, 0); 492 g_assert_cmpint(backing->quiesce_counter, ==, 0); 493 g_assert_cmpint(a_s->drain_count, ==, 0); 494 g_assert_cmpint(b_s->drain_count, ==, 0); 495 g_assert_cmpint(backing_s->drain_count, ==, 0); 496 497 do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); 498 do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); 499 do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); 500 do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b); 501 do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b); 502 503 bdrv_set_backing_hd(bs_b, backing, &error_abort); 504 g_assert_cmpint(bs_a->quiesce_counter, ==, 5); 505 g_assert_cmpint(bs_b->quiesce_counter, ==, 5); 506 g_assert_cmpint(backing->quiesce_counter, ==, 5); 507 g_assert_cmpint(a_s->drain_count, ==, 5); 508 g_assert_cmpint(b_s->drain_count, ==, 5); 509 g_assert_cmpint(backing_s->drain_count, ==, 5); 510 511 bdrv_set_backing_hd(bs_b, NULL, &error_abort); 512 g_assert_cmpint(bs_a->quiesce_counter, ==, 3); 513 g_assert_cmpint(bs_b->quiesce_counter, ==, 2); 514 g_assert_cmpint(backing->quiesce_counter, ==, 3); 515 g_assert_cmpint(a_s->drain_count, ==, 3); 516 g_assert_cmpint(b_s->drain_count, ==, 2); 517 g_assert_cmpint(backing_s->drain_count, ==, 3); 518 519 bdrv_set_backing_hd(bs_b, backing, &error_abort); 520 g_assert_cmpint(bs_a->quiesce_counter, ==, 5); 521 g_assert_cmpint(bs_b->quiesce_counter, ==, 5); 522 g_assert_cmpint(backing->quiesce_counter, ==, 5); 523 g_assert_cmpint(a_s->drain_count, ==, 5); 524 g_assert_cmpint(b_s->drain_count, ==, 5); 525 g_assert_cmpint(backing_s->drain_count, ==, 5); 526 527 do_drain_end(BDRV_SUBTREE_DRAIN, bs_b); 528 do_drain_end(BDRV_SUBTREE_DRAIN, bs_b); 529 do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); 530 do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); 531 do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); 532 533 g_assert_cmpint(bs_a->quiesce_counter, ==, 0); 534 g_assert_cmpint(bs_b->quiesce_counter, ==, 0); 535 g_assert_cmpint(backing->quiesce_counter, ==, 0); 536 g_assert_cmpint(a_s->drain_count, ==, 0); 537 g_assert_cmpint(b_s->drain_count, ==, 0); 538 g_assert_cmpint(backing_s->drain_count, ==, 0); 539 540 bdrv_unref(backing); 541 bdrv_unref(bs_a); 542 bdrv_unref(bs_b); 543 blk_unref(blk_a); 544 blk_unref(blk_b); 545 } 546 547 static void test_graph_change_drain_all(void) 548 { 549 BlockBackend *blk_a, *blk_b; 550 BlockDriverState *bs_a, *bs_b; 551 BDRVTestState *a_s, *b_s; 552 553 /* Create node A with a BlockBackend */ 554 blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 555 bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR, 556 &error_abort); 557 a_s = bs_a->opaque; 558 blk_insert_bs(blk_a, bs_a, &error_abort); 559 560 g_assert_cmpint(bs_a->quiesce_counter, ==, 0); 561 g_assert_cmpint(a_s->drain_count, ==, 0); 562 563 /* Call bdrv_drain_all_begin() */ 564 bdrv_drain_all_begin(); 565 566 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 567 g_assert_cmpint(a_s->drain_count, ==, 1); 568 569 /* Create node B with a BlockBackend */ 570 blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 571 bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR, 572 &error_abort); 573 b_s = bs_b->opaque; 574 blk_insert_bs(blk_b, bs_b, &error_abort); 575 576 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 577 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 578 g_assert_cmpint(a_s->drain_count, ==, 1); 579 g_assert_cmpint(b_s->drain_count, ==, 1); 580 581 /* Unref and finally delete node A */ 582 blk_unref(blk_a); 583 584 g_assert_cmpint(bs_a->quiesce_counter, ==, 1); 585 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 586 g_assert_cmpint(a_s->drain_count, ==, 1); 587 g_assert_cmpint(b_s->drain_count, ==, 1); 588 589 bdrv_unref(bs_a); 590 591 g_assert_cmpint(bs_b->quiesce_counter, ==, 1); 592 g_assert_cmpint(b_s->drain_count, ==, 1); 593 594 /* End the drained section */ 595 bdrv_drain_all_end(); 596 597 g_assert_cmpint(bs_b->quiesce_counter, ==, 0); 598 g_assert_cmpint(b_s->drain_count, ==, 0); 599 g_assert_cmpint(qemu_get_aio_context()->external_disable_cnt, ==, 0); 600 601 bdrv_unref(bs_b); 602 blk_unref(blk_b); 603 } 604 605 struct test_iothread_data { 606 BlockDriverState *bs; 607 enum drain_type drain_type; 608 int *aio_ret; 609 }; 610 611 static void test_iothread_drain_entry(void *opaque) 612 { 613 struct test_iothread_data *data = opaque; 614 615 aio_context_acquire(bdrv_get_aio_context(data->bs)); 616 do_drain_begin(data->drain_type, data->bs); 617 g_assert_cmpint(*data->aio_ret, ==, 0); 618 do_drain_end(data->drain_type, data->bs); 619 aio_context_release(bdrv_get_aio_context(data->bs)); 620 621 qemu_event_set(&done_event); 622 } 623 624 static void test_iothread_aio_cb(void *opaque, int ret) 625 { 626 int *aio_ret = opaque; 627 *aio_ret = ret; 628 qemu_event_set(&done_event); 629 } 630 631 static void test_iothread_main_thread_bh(void *opaque) 632 { 633 struct test_iothread_data *data = opaque; 634 635 /* Test that the AioContext is not yet locked in a random BH that is 636 * executed during drain, otherwise this would deadlock. */ 637 aio_context_acquire(bdrv_get_aio_context(data->bs)); 638 bdrv_flush(data->bs); 639 aio_context_release(bdrv_get_aio_context(data->bs)); 640 } 641 642 /* 643 * Starts an AIO request on a BDS that runs in the AioContext of iothread 1. 644 * The request involves a BH on iothread 2 before it can complete. 645 * 646 * @drain_thread = 0 means that do_drain_begin/end are called from the main 647 * thread, @drain_thread = 1 means that they are called from iothread 1. Drain 648 * for this BDS cannot be called from iothread 2 because only the main thread 649 * may do cross-AioContext polling. 650 */ 651 static void test_iothread_common(enum drain_type drain_type, int drain_thread) 652 { 653 BlockBackend *blk; 654 BlockDriverState *bs; 655 BDRVTestState *s; 656 BlockAIOCB *acb; 657 int aio_ret; 658 struct test_iothread_data data; 659 660 IOThread *a = iothread_new(); 661 IOThread *b = iothread_new(); 662 AioContext *ctx_a = iothread_get_aio_context(a); 663 AioContext *ctx_b = iothread_get_aio_context(b); 664 665 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 666 667 /* bdrv_drain_all() may only be called from the main loop thread */ 668 if (drain_type == BDRV_DRAIN_ALL && drain_thread != 0) { 669 goto out; 670 } 671 672 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 673 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 674 &error_abort); 675 s = bs->opaque; 676 blk_insert_bs(blk, bs, &error_abort); 677 blk_set_disable_request_queuing(blk, true); 678 679 blk_set_aio_context(blk, ctx_a, &error_abort); 680 aio_context_acquire(ctx_a); 681 682 s->bh_indirection_ctx = ctx_b; 683 684 aio_ret = -EINPROGRESS; 685 qemu_event_reset(&done_event); 686 687 if (drain_thread == 0) { 688 acb = blk_aio_preadv(blk, 0, &qiov, 0, test_iothread_aio_cb, &aio_ret); 689 } else { 690 acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); 691 } 692 g_assert(acb != NULL); 693 g_assert_cmpint(aio_ret, ==, -EINPROGRESS); 694 695 aio_context_release(ctx_a); 696 697 data = (struct test_iothread_data) { 698 .bs = bs, 699 .drain_type = drain_type, 700 .aio_ret = &aio_ret, 701 }; 702 703 switch (drain_thread) { 704 case 0: 705 if (drain_type != BDRV_DRAIN_ALL) { 706 aio_context_acquire(ctx_a); 707 } 708 709 aio_bh_schedule_oneshot(ctx_a, test_iothread_main_thread_bh, &data); 710 711 /* The request is running on the IOThread a. Draining its block device 712 * will make sure that it has completed as far as the BDS is concerned, 713 * but the drain in this thread can continue immediately after 714 * bdrv_dec_in_flight() and aio_ret might be assigned only slightly 715 * later. */ 716 do_drain_begin(drain_type, bs); 717 g_assert_cmpint(bs->in_flight, ==, 0); 718 719 if (drain_type != BDRV_DRAIN_ALL) { 720 aio_context_release(ctx_a); 721 } 722 qemu_event_wait(&done_event); 723 if (drain_type != BDRV_DRAIN_ALL) { 724 aio_context_acquire(ctx_a); 725 } 726 727 g_assert_cmpint(aio_ret, ==, 0); 728 do_drain_end(drain_type, bs); 729 730 if (drain_type != BDRV_DRAIN_ALL) { 731 aio_context_release(ctx_a); 732 } 733 break; 734 case 1: 735 aio_bh_schedule_oneshot(ctx_a, test_iothread_drain_entry, &data); 736 qemu_event_wait(&done_event); 737 break; 738 default: 739 g_assert_not_reached(); 740 } 741 742 aio_context_acquire(ctx_a); 743 blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort); 744 aio_context_release(ctx_a); 745 746 bdrv_unref(bs); 747 blk_unref(blk); 748 749 out: 750 iothread_join(a); 751 iothread_join(b); 752 } 753 754 static void test_iothread_drain_all(void) 755 { 756 test_iothread_common(BDRV_DRAIN_ALL, 0); 757 test_iothread_common(BDRV_DRAIN_ALL, 1); 758 } 759 760 static void test_iothread_drain(void) 761 { 762 test_iothread_common(BDRV_DRAIN, 0); 763 test_iothread_common(BDRV_DRAIN, 1); 764 } 765 766 static void test_iothread_drain_subtree(void) 767 { 768 test_iothread_common(BDRV_SUBTREE_DRAIN, 0); 769 test_iothread_common(BDRV_SUBTREE_DRAIN, 1); 770 } 771 772 773 typedef struct TestBlockJob { 774 BlockJob common; 775 BlockDriverState *bs; 776 int run_ret; 777 int prepare_ret; 778 bool running; 779 bool should_complete; 780 } TestBlockJob; 781 782 static int test_job_prepare(Job *job) 783 { 784 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 785 786 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 787 bdrv_flush(s->bs); 788 return s->prepare_ret; 789 } 790 791 static void test_job_commit(Job *job) 792 { 793 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 794 795 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 796 bdrv_flush(s->bs); 797 } 798 799 static void test_job_abort(Job *job) 800 { 801 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 802 803 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 804 bdrv_flush(s->bs); 805 } 806 807 static int coroutine_fn test_job_run(Job *job, Error **errp) 808 { 809 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 810 811 /* We are running the actual job code past the pause point in 812 * job_co_entry(). */ 813 s->running = true; 814 815 job_transition_to_ready(&s->common.job); 816 while (!s->should_complete) { 817 /* Avoid job_sleep_ns() because it marks the job as !busy. We want to 818 * emulate some actual activity (probably some I/O) here so that drain 819 * has to wait for this activity to stop. */ 820 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); 821 822 job_pause_point(&s->common.job); 823 } 824 825 return s->run_ret; 826 } 827 828 static void test_job_complete(Job *job, Error **errp) 829 { 830 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 831 s->should_complete = true; 832 } 833 834 BlockJobDriver test_job_driver = { 835 .job_driver = { 836 .instance_size = sizeof(TestBlockJob), 837 .free = block_job_free, 838 .user_resume = block_job_user_resume, 839 .run = test_job_run, 840 .complete = test_job_complete, 841 .prepare = test_job_prepare, 842 .commit = test_job_commit, 843 .abort = test_job_abort, 844 }, 845 }; 846 847 enum test_job_result { 848 TEST_JOB_SUCCESS, 849 TEST_JOB_FAIL_RUN, 850 TEST_JOB_FAIL_PREPARE, 851 }; 852 853 enum test_job_drain_node { 854 TEST_JOB_DRAIN_SRC, 855 TEST_JOB_DRAIN_SRC_CHILD, 856 TEST_JOB_DRAIN_SRC_PARENT, 857 }; 858 859 static void test_blockjob_common_drain_node(enum drain_type drain_type, 860 bool use_iothread, 861 enum test_job_result result, 862 enum test_job_drain_node drain_node) 863 { 864 BlockBackend *blk_src, *blk_target; 865 BlockDriverState *src, *src_backing, *src_overlay, *target, *drain_bs; 866 BlockJob *job; 867 TestBlockJob *tjob; 868 IOThread *iothread = NULL; 869 AioContext *ctx; 870 int ret; 871 872 src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR, 873 &error_abort); 874 src_backing = bdrv_new_open_driver(&bdrv_test, "source-backing", 875 BDRV_O_RDWR, &error_abort); 876 src_overlay = bdrv_new_open_driver(&bdrv_test, "source-overlay", 877 BDRV_O_RDWR, &error_abort); 878 879 bdrv_set_backing_hd(src_overlay, src, &error_abort); 880 bdrv_unref(src); 881 bdrv_set_backing_hd(src, src_backing, &error_abort); 882 bdrv_unref(src_backing); 883 884 blk_src = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 885 blk_insert_bs(blk_src, src_overlay, &error_abort); 886 887 switch (drain_node) { 888 case TEST_JOB_DRAIN_SRC: 889 drain_bs = src; 890 break; 891 case TEST_JOB_DRAIN_SRC_CHILD: 892 drain_bs = src_backing; 893 break; 894 case TEST_JOB_DRAIN_SRC_PARENT: 895 drain_bs = src_overlay; 896 break; 897 default: 898 g_assert_not_reached(); 899 } 900 901 if (use_iothread) { 902 iothread = iothread_new(); 903 ctx = iothread_get_aio_context(iothread); 904 blk_set_aio_context(blk_src, ctx, &error_abort); 905 } else { 906 ctx = qemu_get_aio_context(); 907 } 908 909 target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR, 910 &error_abort); 911 blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 912 blk_insert_bs(blk_target, target, &error_abort); 913 blk_set_allow_aio_context_change(blk_target, true); 914 915 aio_context_acquire(ctx); 916 tjob = block_job_create("job0", &test_job_driver, NULL, src, 917 0, BLK_PERM_ALL, 918 0, 0, NULL, NULL, &error_abort); 919 tjob->bs = src; 920 job = &tjob->common; 921 block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort); 922 923 switch (result) { 924 case TEST_JOB_SUCCESS: 925 break; 926 case TEST_JOB_FAIL_RUN: 927 tjob->run_ret = -EIO; 928 break; 929 case TEST_JOB_FAIL_PREPARE: 930 tjob->prepare_ret = -EIO; 931 break; 932 } 933 934 job_start(&job->job); 935 aio_context_release(ctx); 936 937 if (use_iothread) { 938 /* job_co_entry() is run in the I/O thread, wait for the actual job 939 * code to start (we don't want to catch the job in the pause point in 940 * job_co_entry(). */ 941 while (!tjob->running) { 942 aio_poll(qemu_get_aio_context(), false); 943 } 944 } 945 946 g_assert_cmpint(job->job.pause_count, ==, 0); 947 g_assert_false(job->job.paused); 948 g_assert_true(tjob->running); 949 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 950 951 do_drain_begin_unlocked(drain_type, drain_bs); 952 953 if (drain_type == BDRV_DRAIN_ALL) { 954 /* bdrv_drain_all() drains both src and target */ 955 g_assert_cmpint(job->job.pause_count, ==, 2); 956 } else { 957 g_assert_cmpint(job->job.pause_count, ==, 1); 958 } 959 g_assert_true(job->job.paused); 960 g_assert_false(job->job.busy); /* The job is paused */ 961 962 do_drain_end_unlocked(drain_type, drain_bs); 963 964 if (use_iothread) { 965 /* paused is reset in the I/O thread, wait for it */ 966 while (job->job.paused) { 967 aio_poll(qemu_get_aio_context(), false); 968 } 969 } 970 971 g_assert_cmpint(job->job.pause_count, ==, 0); 972 g_assert_false(job->job.paused); 973 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 974 975 do_drain_begin_unlocked(drain_type, target); 976 977 if (drain_type == BDRV_DRAIN_ALL) { 978 /* bdrv_drain_all() drains both src and target */ 979 g_assert_cmpint(job->job.pause_count, ==, 2); 980 } else { 981 g_assert_cmpint(job->job.pause_count, ==, 1); 982 } 983 g_assert_true(job->job.paused); 984 g_assert_false(job->job.busy); /* The job is paused */ 985 986 do_drain_end_unlocked(drain_type, target); 987 988 if (use_iothread) { 989 /* paused is reset in the I/O thread, wait for it */ 990 while (job->job.paused) { 991 aio_poll(qemu_get_aio_context(), false); 992 } 993 } 994 995 g_assert_cmpint(job->job.pause_count, ==, 0); 996 g_assert_false(job->job.paused); 997 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 998 999 aio_context_acquire(ctx); 1000 ret = job_complete_sync(&job->job, &error_abort); 1001 g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO)); 1002 1003 if (use_iothread) { 1004 blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort); 1005 assert(blk_get_aio_context(blk_target) == qemu_get_aio_context()); 1006 } 1007 aio_context_release(ctx); 1008 1009 blk_unref(blk_src); 1010 blk_unref(blk_target); 1011 bdrv_unref(src_overlay); 1012 bdrv_unref(target); 1013 1014 if (iothread) { 1015 iothread_join(iothread); 1016 } 1017 } 1018 1019 static void test_blockjob_common(enum drain_type drain_type, bool use_iothread, 1020 enum test_job_result result) 1021 { 1022 test_blockjob_common_drain_node(drain_type, use_iothread, result, 1023 TEST_JOB_DRAIN_SRC); 1024 test_blockjob_common_drain_node(drain_type, use_iothread, result, 1025 TEST_JOB_DRAIN_SRC_CHILD); 1026 if (drain_type == BDRV_SUBTREE_DRAIN) { 1027 test_blockjob_common_drain_node(drain_type, use_iothread, result, 1028 TEST_JOB_DRAIN_SRC_PARENT); 1029 } 1030 } 1031 1032 static void test_blockjob_drain_all(void) 1033 { 1034 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS); 1035 } 1036 1037 static void test_blockjob_drain(void) 1038 { 1039 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_SUCCESS); 1040 } 1041 1042 static void test_blockjob_drain_subtree(void) 1043 { 1044 test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_SUCCESS); 1045 } 1046 1047 static void test_blockjob_error_drain_all(void) 1048 { 1049 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_RUN); 1050 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_PREPARE); 1051 } 1052 1053 static void test_blockjob_error_drain(void) 1054 { 1055 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_RUN); 1056 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_PREPARE); 1057 } 1058 1059 static void test_blockjob_error_drain_subtree(void) 1060 { 1061 test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_RUN); 1062 test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_PREPARE); 1063 } 1064 1065 static void test_blockjob_iothread_drain_all(void) 1066 { 1067 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_SUCCESS); 1068 } 1069 1070 static void test_blockjob_iothread_drain(void) 1071 { 1072 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_SUCCESS); 1073 } 1074 1075 static void test_blockjob_iothread_drain_subtree(void) 1076 { 1077 test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_SUCCESS); 1078 } 1079 1080 static void test_blockjob_iothread_error_drain_all(void) 1081 { 1082 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_RUN); 1083 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_PREPARE); 1084 } 1085 1086 static void test_blockjob_iothread_error_drain(void) 1087 { 1088 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_RUN); 1089 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_PREPARE); 1090 } 1091 1092 static void test_blockjob_iothread_error_drain_subtree(void) 1093 { 1094 test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_RUN); 1095 test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_PREPARE); 1096 } 1097 1098 1099 typedef struct BDRVTestTopState { 1100 BdrvChild *wait_child; 1101 } BDRVTestTopState; 1102 1103 static void bdrv_test_top_close(BlockDriverState *bs) 1104 { 1105 BdrvChild *c, *next_c; 1106 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 1107 bdrv_unref_child(bs, c); 1108 } 1109 } 1110 1111 static int coroutine_fn bdrv_test_top_co_preadv(BlockDriverState *bs, 1112 int64_t offset, int64_t bytes, 1113 QEMUIOVector *qiov, 1114 BdrvRequestFlags flags) 1115 { 1116 BDRVTestTopState *tts = bs->opaque; 1117 return bdrv_co_preadv(tts->wait_child, offset, bytes, qiov, flags); 1118 } 1119 1120 static BlockDriver bdrv_test_top_driver = { 1121 .format_name = "test_top_driver", 1122 .instance_size = sizeof(BDRVTestTopState), 1123 1124 .bdrv_close = bdrv_test_top_close, 1125 .bdrv_co_preadv = bdrv_test_top_co_preadv, 1126 1127 .bdrv_child_perm = bdrv_default_perms, 1128 }; 1129 1130 typedef struct TestCoDeleteByDrainData { 1131 BlockBackend *blk; 1132 bool detach_instead_of_delete; 1133 bool done; 1134 } TestCoDeleteByDrainData; 1135 1136 static void coroutine_fn test_co_delete_by_drain(void *opaque) 1137 { 1138 TestCoDeleteByDrainData *dbdd = opaque; 1139 BlockBackend *blk = dbdd->blk; 1140 BlockDriverState *bs = blk_bs(blk); 1141 BDRVTestTopState *tts = bs->opaque; 1142 void *buffer = g_malloc(65536); 1143 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buffer, 65536); 1144 1145 /* Pretend some internal write operation from parent to child. 1146 * Important: We have to read from the child, not from the parent! 1147 * Draining works by first propagating it all up the tree to the 1148 * root and then waiting for drainage from root to the leaves 1149 * (protocol nodes). If we have a request waiting on the root, 1150 * everything will be drained before we go back down the tree, but 1151 * we do not want that. We want to be in the middle of draining 1152 * when this following requests returns. */ 1153 bdrv_co_preadv(tts->wait_child, 0, 65536, &qiov, 0); 1154 1155 g_assert_cmpint(bs->refcnt, ==, 1); 1156 1157 if (!dbdd->detach_instead_of_delete) { 1158 blk_unref(blk); 1159 } else { 1160 BdrvChild *c, *next_c; 1161 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 1162 bdrv_unref_child(bs, c); 1163 } 1164 } 1165 1166 dbdd->done = true; 1167 g_free(buffer); 1168 } 1169 1170 /** 1171 * Test what happens when some BDS has some children, you drain one of 1172 * them and this results in the BDS being deleted. 1173 * 1174 * If @detach_instead_of_delete is set, the BDS is not going to be 1175 * deleted but will only detach all of its children. 1176 */ 1177 static void do_test_delete_by_drain(bool detach_instead_of_delete, 1178 enum drain_type drain_type) 1179 { 1180 BlockBackend *blk; 1181 BlockDriverState *bs, *child_bs, *null_bs; 1182 BDRVTestTopState *tts; 1183 TestCoDeleteByDrainData dbdd; 1184 Coroutine *co; 1185 1186 bs = bdrv_new_open_driver(&bdrv_test_top_driver, "top", BDRV_O_RDWR, 1187 &error_abort); 1188 bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1189 tts = bs->opaque; 1190 1191 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1192 &error_abort); 1193 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, 1194 BDRV_CHILD_DATA, &error_abort); 1195 1196 /* This child will be the one to pass to requests through to, and 1197 * it will stall until a drain occurs */ 1198 child_bs = bdrv_new_open_driver(&bdrv_test, "child", BDRV_O_RDWR, 1199 &error_abort); 1200 child_bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1201 /* Takes our reference to child_bs */ 1202 tts->wait_child = bdrv_attach_child(bs, child_bs, "wait-child", 1203 &child_of_bds, 1204 BDRV_CHILD_DATA | BDRV_CHILD_PRIMARY, 1205 &error_abort); 1206 1207 /* This child is just there to be deleted 1208 * (for detach_instead_of_delete == true) */ 1209 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1210 &error_abort); 1211 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, BDRV_CHILD_DATA, 1212 &error_abort); 1213 1214 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1215 blk_insert_bs(blk, bs, &error_abort); 1216 1217 /* Referenced by blk now */ 1218 bdrv_unref(bs); 1219 1220 g_assert_cmpint(bs->refcnt, ==, 1); 1221 g_assert_cmpint(child_bs->refcnt, ==, 1); 1222 g_assert_cmpint(null_bs->refcnt, ==, 1); 1223 1224 1225 dbdd = (TestCoDeleteByDrainData){ 1226 .blk = blk, 1227 .detach_instead_of_delete = detach_instead_of_delete, 1228 .done = false, 1229 }; 1230 co = qemu_coroutine_create(test_co_delete_by_drain, &dbdd); 1231 qemu_coroutine_enter(co); 1232 1233 /* Drain the child while the read operation is still pending. 1234 * This should result in the operation finishing and 1235 * test_co_delete_by_drain() resuming. Thus, @bs will be deleted 1236 * and the coroutine will exit while this drain operation is still 1237 * in progress. */ 1238 switch (drain_type) { 1239 case BDRV_DRAIN: 1240 bdrv_ref(child_bs); 1241 bdrv_drain(child_bs); 1242 bdrv_unref(child_bs); 1243 break; 1244 case BDRV_SUBTREE_DRAIN: 1245 /* Would have to ref/unref bs here for !detach_instead_of_delete, but 1246 * then the whole test becomes pointless because the graph changes 1247 * don't occur during the drain any more. */ 1248 assert(detach_instead_of_delete); 1249 bdrv_subtree_drained_begin(bs); 1250 bdrv_subtree_drained_end(bs); 1251 break; 1252 case BDRV_DRAIN_ALL: 1253 bdrv_drain_all_begin(); 1254 bdrv_drain_all_end(); 1255 break; 1256 default: 1257 g_assert_not_reached(); 1258 } 1259 1260 while (!dbdd.done) { 1261 aio_poll(qemu_get_aio_context(), true); 1262 } 1263 1264 if (detach_instead_of_delete) { 1265 /* Here, the reference has not passed over to the coroutine, 1266 * so we have to delete the BB ourselves */ 1267 blk_unref(blk); 1268 } 1269 } 1270 1271 static void test_delete_by_drain(void) 1272 { 1273 do_test_delete_by_drain(false, BDRV_DRAIN); 1274 } 1275 1276 static void test_detach_by_drain_all(void) 1277 { 1278 do_test_delete_by_drain(true, BDRV_DRAIN_ALL); 1279 } 1280 1281 static void test_detach_by_drain(void) 1282 { 1283 do_test_delete_by_drain(true, BDRV_DRAIN); 1284 } 1285 1286 static void test_detach_by_drain_subtree(void) 1287 { 1288 do_test_delete_by_drain(true, BDRV_SUBTREE_DRAIN); 1289 } 1290 1291 1292 struct detach_by_parent_data { 1293 BlockDriverState *parent_b; 1294 BdrvChild *child_b; 1295 BlockDriverState *c; 1296 BdrvChild *child_c; 1297 bool by_parent_cb; 1298 }; 1299 static struct detach_by_parent_data detach_by_parent_data; 1300 1301 static void detach_indirect_bh(void *opaque) 1302 { 1303 struct detach_by_parent_data *data = opaque; 1304 1305 bdrv_unref_child(data->parent_b, data->child_b); 1306 1307 bdrv_ref(data->c); 1308 data->child_c = bdrv_attach_child(data->parent_b, data->c, "PB-C", 1309 &child_of_bds, BDRV_CHILD_DATA, 1310 &error_abort); 1311 } 1312 1313 static void detach_by_parent_aio_cb(void *opaque, int ret) 1314 { 1315 struct detach_by_parent_data *data = &detach_by_parent_data; 1316 1317 g_assert_cmpint(ret, ==, 0); 1318 if (data->by_parent_cb) { 1319 detach_indirect_bh(data); 1320 } 1321 } 1322 1323 static void detach_by_driver_cb_drained_begin(BdrvChild *child) 1324 { 1325 aio_bh_schedule_oneshot(qemu_get_current_aio_context(), 1326 detach_indirect_bh, &detach_by_parent_data); 1327 child_of_bds.drained_begin(child); 1328 } 1329 1330 static BdrvChildClass detach_by_driver_cb_class; 1331 1332 /* 1333 * Initial graph: 1334 * 1335 * PA PB 1336 * \ / \ 1337 * A B C 1338 * 1339 * by_parent_cb == true: Test that parent callbacks don't poll 1340 * 1341 * PA has a pending write request whose callback changes the child nodes of 1342 * PB: It removes B and adds C instead. The subtree of PB is drained, which 1343 * will indirectly drain the write request, too. 1344 * 1345 * by_parent_cb == false: Test that bdrv_drain_invoke() doesn't poll 1346 * 1347 * PA's BdrvChildClass has a .drained_begin callback that schedules a BH 1348 * that does the same graph change. If bdrv_drain_invoke() calls it, the 1349 * state is messed up, but if it is only polled in the single 1350 * BDRV_POLL_WHILE() at the end of the drain, this should work fine. 1351 */ 1352 static void test_detach_indirect(bool by_parent_cb) 1353 { 1354 BlockBackend *blk; 1355 BlockDriverState *parent_a, *parent_b, *a, *b, *c; 1356 BdrvChild *child_a, *child_b; 1357 BlockAIOCB *acb; 1358 1359 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 1360 1361 if (!by_parent_cb) { 1362 detach_by_driver_cb_class = child_of_bds; 1363 detach_by_driver_cb_class.drained_begin = 1364 detach_by_driver_cb_drained_begin; 1365 } 1366 1367 /* Create all involved nodes */ 1368 parent_a = bdrv_new_open_driver(&bdrv_test, "parent-a", BDRV_O_RDWR, 1369 &error_abort); 1370 parent_b = bdrv_new_open_driver(&bdrv_test, "parent-b", 0, 1371 &error_abort); 1372 1373 a = bdrv_new_open_driver(&bdrv_test, "a", BDRV_O_RDWR, &error_abort); 1374 b = bdrv_new_open_driver(&bdrv_test, "b", BDRV_O_RDWR, &error_abort); 1375 c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort); 1376 1377 /* blk is a BB for parent-a */ 1378 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1379 blk_insert_bs(blk, parent_a, &error_abort); 1380 bdrv_unref(parent_a); 1381 1382 /* If we want to get bdrv_drain_invoke() to call aio_poll(), the driver 1383 * callback must not return immediately. */ 1384 if (!by_parent_cb) { 1385 BDRVTestState *s = parent_a->opaque; 1386 s->sleep_in_drain_begin = true; 1387 } 1388 1389 /* Set child relationships */ 1390 bdrv_ref(b); 1391 bdrv_ref(a); 1392 child_b = bdrv_attach_child(parent_b, b, "PB-B", &child_of_bds, 1393 BDRV_CHILD_DATA, &error_abort); 1394 child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_of_bds, 1395 BDRV_CHILD_COW, &error_abort); 1396 1397 bdrv_ref(a); 1398 bdrv_attach_child(parent_a, a, "PA-A", 1399 by_parent_cb ? &child_of_bds : &detach_by_driver_cb_class, 1400 BDRV_CHILD_DATA, &error_abort); 1401 1402 g_assert_cmpint(parent_a->refcnt, ==, 1); 1403 g_assert_cmpint(parent_b->refcnt, ==, 1); 1404 g_assert_cmpint(a->refcnt, ==, 3); 1405 g_assert_cmpint(b->refcnt, ==, 2); 1406 g_assert_cmpint(c->refcnt, ==, 1); 1407 1408 g_assert(QLIST_FIRST(&parent_b->children) == child_a); 1409 g_assert(QLIST_NEXT(child_a, next) == child_b); 1410 g_assert(QLIST_NEXT(child_b, next) == NULL); 1411 1412 /* Start the evil write request */ 1413 detach_by_parent_data = (struct detach_by_parent_data) { 1414 .parent_b = parent_b, 1415 .child_b = child_b, 1416 .c = c, 1417 .by_parent_cb = by_parent_cb, 1418 }; 1419 acb = blk_aio_preadv(blk, 0, &qiov, 0, detach_by_parent_aio_cb, NULL); 1420 g_assert(acb != NULL); 1421 1422 /* Drain and check the expected result */ 1423 bdrv_subtree_drained_begin(parent_b); 1424 1425 g_assert(detach_by_parent_data.child_c != NULL); 1426 1427 g_assert_cmpint(parent_a->refcnt, ==, 1); 1428 g_assert_cmpint(parent_b->refcnt, ==, 1); 1429 g_assert_cmpint(a->refcnt, ==, 3); 1430 g_assert_cmpint(b->refcnt, ==, 1); 1431 g_assert_cmpint(c->refcnt, ==, 2); 1432 1433 g_assert(QLIST_FIRST(&parent_b->children) == detach_by_parent_data.child_c); 1434 g_assert(QLIST_NEXT(detach_by_parent_data.child_c, next) == child_a); 1435 g_assert(QLIST_NEXT(child_a, next) == NULL); 1436 1437 g_assert_cmpint(parent_a->quiesce_counter, ==, 1); 1438 g_assert_cmpint(parent_b->quiesce_counter, ==, 1); 1439 g_assert_cmpint(a->quiesce_counter, ==, 1); 1440 g_assert_cmpint(b->quiesce_counter, ==, 0); 1441 g_assert_cmpint(c->quiesce_counter, ==, 1); 1442 1443 bdrv_subtree_drained_end(parent_b); 1444 1445 bdrv_unref(parent_b); 1446 blk_unref(blk); 1447 1448 g_assert_cmpint(a->refcnt, ==, 1); 1449 g_assert_cmpint(b->refcnt, ==, 1); 1450 g_assert_cmpint(c->refcnt, ==, 1); 1451 bdrv_unref(a); 1452 bdrv_unref(b); 1453 bdrv_unref(c); 1454 } 1455 1456 static void test_detach_by_parent_cb(void) 1457 { 1458 test_detach_indirect(true); 1459 } 1460 1461 static void test_detach_by_driver_cb(void) 1462 { 1463 test_detach_indirect(false); 1464 } 1465 1466 static void test_append_to_drained(void) 1467 { 1468 BlockBackend *blk; 1469 BlockDriverState *base, *overlay; 1470 BDRVTestState *base_s, *overlay_s; 1471 1472 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1473 base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort); 1474 base_s = base->opaque; 1475 blk_insert_bs(blk, base, &error_abort); 1476 1477 overlay = bdrv_new_open_driver(&bdrv_test, "overlay", BDRV_O_RDWR, 1478 &error_abort); 1479 overlay_s = overlay->opaque; 1480 1481 do_drain_begin(BDRV_DRAIN, base); 1482 g_assert_cmpint(base->quiesce_counter, ==, 1); 1483 g_assert_cmpint(base_s->drain_count, ==, 1); 1484 g_assert_cmpint(base->in_flight, ==, 0); 1485 1486 bdrv_append(overlay, base, &error_abort); 1487 g_assert_cmpint(base->in_flight, ==, 0); 1488 g_assert_cmpint(overlay->in_flight, ==, 0); 1489 1490 g_assert_cmpint(base->quiesce_counter, ==, 1); 1491 g_assert_cmpint(base_s->drain_count, ==, 1); 1492 g_assert_cmpint(overlay->quiesce_counter, ==, 1); 1493 g_assert_cmpint(overlay_s->drain_count, ==, 1); 1494 1495 do_drain_end(BDRV_DRAIN, base); 1496 1497 g_assert_cmpint(base->quiesce_counter, ==, 0); 1498 g_assert_cmpint(base_s->drain_count, ==, 0); 1499 g_assert_cmpint(overlay->quiesce_counter, ==, 0); 1500 g_assert_cmpint(overlay_s->drain_count, ==, 0); 1501 1502 bdrv_unref(overlay); 1503 bdrv_unref(base); 1504 blk_unref(blk); 1505 } 1506 1507 static void test_set_aio_context(void) 1508 { 1509 BlockDriverState *bs; 1510 IOThread *a = iothread_new(); 1511 IOThread *b = iothread_new(); 1512 AioContext *ctx_a = iothread_get_aio_context(a); 1513 AioContext *ctx_b = iothread_get_aio_context(b); 1514 1515 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 1516 &error_abort); 1517 1518 bdrv_drained_begin(bs); 1519 bdrv_try_set_aio_context(bs, ctx_a, &error_abort); 1520 1521 aio_context_acquire(ctx_a); 1522 bdrv_drained_end(bs); 1523 1524 bdrv_drained_begin(bs); 1525 bdrv_try_set_aio_context(bs, ctx_b, &error_abort); 1526 aio_context_release(ctx_a); 1527 aio_context_acquire(ctx_b); 1528 bdrv_try_set_aio_context(bs, qemu_get_aio_context(), &error_abort); 1529 aio_context_release(ctx_b); 1530 bdrv_drained_end(bs); 1531 1532 bdrv_unref(bs); 1533 iothread_join(a); 1534 iothread_join(b); 1535 } 1536 1537 1538 typedef struct TestDropBackingBlockJob { 1539 BlockJob common; 1540 bool should_complete; 1541 bool *did_complete; 1542 BlockDriverState *detach_also; 1543 BlockDriverState *bs; 1544 } TestDropBackingBlockJob; 1545 1546 static int coroutine_fn test_drop_backing_job_run(Job *job, Error **errp) 1547 { 1548 TestDropBackingBlockJob *s = 1549 container_of(job, TestDropBackingBlockJob, common.job); 1550 1551 while (!s->should_complete) { 1552 job_sleep_ns(job, 0); 1553 } 1554 1555 return 0; 1556 } 1557 1558 static void test_drop_backing_job_commit(Job *job) 1559 { 1560 TestDropBackingBlockJob *s = 1561 container_of(job, TestDropBackingBlockJob, common.job); 1562 1563 bdrv_set_backing_hd(s->bs, NULL, &error_abort); 1564 bdrv_set_backing_hd(s->detach_also, NULL, &error_abort); 1565 1566 *s->did_complete = true; 1567 } 1568 1569 static const BlockJobDriver test_drop_backing_job_driver = { 1570 .job_driver = { 1571 .instance_size = sizeof(TestDropBackingBlockJob), 1572 .free = block_job_free, 1573 .user_resume = block_job_user_resume, 1574 .run = test_drop_backing_job_run, 1575 .commit = test_drop_backing_job_commit, 1576 } 1577 }; 1578 1579 /** 1580 * Creates a child node with three parent nodes on it, and then runs a 1581 * block job on the final one, parent-node-2. 1582 * 1583 * The job is then asked to complete before a section where the child 1584 * is drained. 1585 * 1586 * Ending this section will undrain the child's parents, first 1587 * parent-node-2, then parent-node-1, then parent-node-0 -- the parent 1588 * list is in reverse order of how they were added. Ending the drain 1589 * on parent-node-2 will resume the job, thus completing it and 1590 * scheduling job_exit(). 1591 * 1592 * Ending the drain on parent-node-1 will poll the AioContext, which 1593 * lets job_exit() and thus test_drop_backing_job_commit() run. That 1594 * function first removes the child as parent-node-2's backing file. 1595 * 1596 * In old (and buggy) implementations, there are two problems with 1597 * that: 1598 * (A) bdrv_drain_invoke() polls for every node that leaves the 1599 * drained section. This means that job_exit() is scheduled 1600 * before the child has left the drained section. Its 1601 * quiesce_counter is therefore still 1 when it is removed from 1602 * parent-node-2. 1603 * 1604 * (B) bdrv_replace_child_noperm() calls drained_end() on the old 1605 * child's parents as many times as the child is quiesced. This 1606 * means it will call drained_end() on parent-node-2 once. 1607 * Because parent-node-2 is no longer quiesced at this point, this 1608 * will fail. 1609 * 1610 * bdrv_replace_child_noperm() therefore must call drained_end() on 1611 * the parent only if it really is still drained because the child is 1612 * drained. 1613 * 1614 * If removing child from parent-node-2 was successful (as it should 1615 * be), test_drop_backing_job_commit() will then also remove the child 1616 * from parent-node-0. 1617 * 1618 * With an old version of our drain infrastructure ((A) above), that 1619 * resulted in the following flow: 1620 * 1621 * 1. child attempts to leave its drained section. The call recurses 1622 * to its parents. 1623 * 1624 * 2. parent-node-2 leaves the drained section. Polling in 1625 * bdrv_drain_invoke() will schedule job_exit(). 1626 * 1627 * 3. parent-node-1 leaves the drained section. Polling in 1628 * bdrv_drain_invoke() will run job_exit(), thus disconnecting 1629 * parent-node-0 from the child node. 1630 * 1631 * 4. bdrv_parent_drained_end() uses a QLIST_FOREACH_SAFE() loop to 1632 * iterate over the parents. Thus, it now accesses the BdrvChild 1633 * object that used to connect parent-node-0 and the child node. 1634 * However, that object no longer exists, so it accesses a dangling 1635 * pointer. 1636 * 1637 * The solution is to only poll once when running a bdrv_drained_end() 1638 * operation, specifically at the end when all drained_end() 1639 * operations for all involved nodes have been scheduled. 1640 * Note that this also solves (A) above, thus hiding (B). 1641 */ 1642 static void test_blockjob_commit_by_drained_end(void) 1643 { 1644 BlockDriverState *bs_child, *bs_parents[3]; 1645 TestDropBackingBlockJob *job; 1646 bool job_has_completed = false; 1647 int i; 1648 1649 bs_child = bdrv_new_open_driver(&bdrv_test, "child-node", BDRV_O_RDWR, 1650 &error_abort); 1651 1652 for (i = 0; i < 3; i++) { 1653 char name[32]; 1654 snprintf(name, sizeof(name), "parent-node-%i", i); 1655 bs_parents[i] = bdrv_new_open_driver(&bdrv_test, name, BDRV_O_RDWR, 1656 &error_abort); 1657 bdrv_set_backing_hd(bs_parents[i], bs_child, &error_abort); 1658 } 1659 1660 job = block_job_create("job", &test_drop_backing_job_driver, NULL, 1661 bs_parents[2], 0, BLK_PERM_ALL, 0, 0, NULL, NULL, 1662 &error_abort); 1663 job->bs = bs_parents[2]; 1664 1665 job->detach_also = bs_parents[0]; 1666 job->did_complete = &job_has_completed; 1667 1668 job_start(&job->common.job); 1669 1670 job->should_complete = true; 1671 bdrv_drained_begin(bs_child); 1672 g_assert(!job_has_completed); 1673 bdrv_drained_end(bs_child); 1674 g_assert(job_has_completed); 1675 1676 bdrv_unref(bs_parents[0]); 1677 bdrv_unref(bs_parents[1]); 1678 bdrv_unref(bs_parents[2]); 1679 bdrv_unref(bs_child); 1680 } 1681 1682 1683 typedef struct TestSimpleBlockJob { 1684 BlockJob common; 1685 bool should_complete; 1686 bool *did_complete; 1687 } TestSimpleBlockJob; 1688 1689 static int coroutine_fn test_simple_job_run(Job *job, Error **errp) 1690 { 1691 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1692 1693 while (!s->should_complete) { 1694 job_sleep_ns(job, 0); 1695 } 1696 1697 return 0; 1698 } 1699 1700 static void test_simple_job_clean(Job *job) 1701 { 1702 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1703 *s->did_complete = true; 1704 } 1705 1706 static const BlockJobDriver test_simple_job_driver = { 1707 .job_driver = { 1708 .instance_size = sizeof(TestSimpleBlockJob), 1709 .free = block_job_free, 1710 .user_resume = block_job_user_resume, 1711 .run = test_simple_job_run, 1712 .clean = test_simple_job_clean, 1713 }, 1714 }; 1715 1716 static int drop_intermediate_poll_update_filename(BdrvChild *child, 1717 BlockDriverState *new_base, 1718 const char *filename, 1719 Error **errp) 1720 { 1721 /* 1722 * We are free to poll here, which may change the block graph, if 1723 * it is not drained. 1724 */ 1725 1726 /* If the job is not drained: Complete it, schedule job_exit() */ 1727 aio_poll(qemu_get_current_aio_context(), false); 1728 /* If the job is not drained: Run job_exit(), finish the job */ 1729 aio_poll(qemu_get_current_aio_context(), false); 1730 1731 return 0; 1732 } 1733 1734 /** 1735 * Test a poll in the midst of bdrv_drop_intermediate(). 1736 * 1737 * bdrv_drop_intermediate() calls BdrvChildClass.update_filename(), 1738 * which can yield or poll. This may lead to graph changes, unless 1739 * the whole subtree in question is drained. 1740 * 1741 * We test this on the following graph: 1742 * 1743 * Job 1744 * 1745 * | 1746 * job-node 1747 * | 1748 * v 1749 * 1750 * job-node 1751 * 1752 * | 1753 * backing 1754 * | 1755 * v 1756 * 1757 * node-2 --chain--> node-1 --chain--> node-0 1758 * 1759 * We drop node-1 with bdrv_drop_intermediate(top=node-1, base=node-0). 1760 * 1761 * This first updates node-2's backing filename by invoking 1762 * drop_intermediate_poll_update_filename(), which polls twice. This 1763 * causes the job to finish, which in turns causes the job-node to be 1764 * deleted. 1765 * 1766 * bdrv_drop_intermediate() uses a QLIST_FOREACH_SAFE() loop, so it 1767 * already has a pointer to the BdrvChild edge between job-node and 1768 * node-1. When it tries to handle that edge, we probably get a 1769 * segmentation fault because the object no longer exists. 1770 * 1771 * 1772 * The solution is for bdrv_drop_intermediate() to drain top's 1773 * subtree. This prevents graph changes from happening just because 1774 * BdrvChildClass.update_filename() yields or polls. Thus, the block 1775 * job is paused during that drained section and must finish before or 1776 * after. 1777 * 1778 * (In addition, bdrv_replace_child() must keep the job paused.) 1779 */ 1780 static void test_drop_intermediate_poll(void) 1781 { 1782 static BdrvChildClass chain_child_class; 1783 BlockDriverState *chain[3]; 1784 TestSimpleBlockJob *job; 1785 BlockDriverState *job_node; 1786 bool job_has_completed = false; 1787 int i; 1788 int ret; 1789 1790 chain_child_class = child_of_bds; 1791 chain_child_class.update_filename = drop_intermediate_poll_update_filename; 1792 1793 for (i = 0; i < 3; i++) { 1794 char name[32]; 1795 snprintf(name, 32, "node-%i", i); 1796 1797 chain[i] = bdrv_new_open_driver(&bdrv_test, name, 0, &error_abort); 1798 } 1799 1800 job_node = bdrv_new_open_driver(&bdrv_test, "job-node", BDRV_O_RDWR, 1801 &error_abort); 1802 bdrv_set_backing_hd(job_node, chain[1], &error_abort); 1803 1804 /* 1805 * Establish the chain last, so the chain links are the first 1806 * elements in the BDS.parents lists 1807 */ 1808 for (i = 0; i < 3; i++) { 1809 if (i) { 1810 /* Takes the reference to chain[i - 1] */ 1811 chain[i]->backing = bdrv_attach_child(chain[i], chain[i - 1], 1812 "chain", &chain_child_class, 1813 BDRV_CHILD_COW, &error_abort); 1814 } 1815 } 1816 1817 job = block_job_create("job", &test_simple_job_driver, NULL, job_node, 1818 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort); 1819 1820 /* The job has a reference now */ 1821 bdrv_unref(job_node); 1822 1823 job->did_complete = &job_has_completed; 1824 1825 job_start(&job->common.job); 1826 job->should_complete = true; 1827 1828 g_assert(!job_has_completed); 1829 ret = bdrv_drop_intermediate(chain[1], chain[0], NULL); 1830 g_assert(ret == 0); 1831 g_assert(job_has_completed); 1832 1833 bdrv_unref(chain[2]); 1834 } 1835 1836 1837 typedef struct BDRVReplaceTestState { 1838 bool was_drained; 1839 bool was_undrained; 1840 bool has_read; 1841 1842 int drain_count; 1843 1844 bool yield_before_read; 1845 Coroutine *io_co; 1846 Coroutine *drain_co; 1847 } BDRVReplaceTestState; 1848 1849 static void bdrv_replace_test_close(BlockDriverState *bs) 1850 { 1851 } 1852 1853 /** 1854 * If @bs has a backing file: 1855 * Yield if .yield_before_read is true (and wait for drain_begin to 1856 * wake us up). 1857 * Forward the read to bs->backing. Set .has_read to true. 1858 * If drain_begin has woken us, wake it in turn. 1859 * 1860 * Otherwise: 1861 * Set .has_read to true and return success. 1862 */ 1863 static int coroutine_fn bdrv_replace_test_co_preadv(BlockDriverState *bs, 1864 int64_t offset, 1865 int64_t bytes, 1866 QEMUIOVector *qiov, 1867 BdrvRequestFlags flags) 1868 { 1869 BDRVReplaceTestState *s = bs->opaque; 1870 1871 if (bs->backing) { 1872 int ret; 1873 1874 g_assert(!s->drain_count); 1875 1876 s->io_co = qemu_coroutine_self(); 1877 if (s->yield_before_read) { 1878 s->yield_before_read = false; 1879 qemu_coroutine_yield(); 1880 } 1881 s->io_co = NULL; 1882 1883 ret = bdrv_co_preadv(bs->backing, offset, bytes, qiov, 0); 1884 s->has_read = true; 1885 1886 /* Wake up drain_co if it runs */ 1887 if (s->drain_co) { 1888 aio_co_wake(s->drain_co); 1889 } 1890 1891 return ret; 1892 } 1893 1894 s->has_read = true; 1895 return 0; 1896 } 1897 1898 /** 1899 * If .drain_count is 0, wake up .io_co if there is one; and set 1900 * .was_drained. 1901 * Increment .drain_count. 1902 */ 1903 static void coroutine_fn bdrv_replace_test_co_drain_begin(BlockDriverState *bs) 1904 { 1905 BDRVReplaceTestState *s = bs->opaque; 1906 1907 if (!s->drain_count) { 1908 /* Keep waking io_co up until it is done */ 1909 s->drain_co = qemu_coroutine_self(); 1910 while (s->io_co) { 1911 aio_co_wake(s->io_co); 1912 s->io_co = NULL; 1913 qemu_coroutine_yield(); 1914 } 1915 s->drain_co = NULL; 1916 1917 s->was_drained = true; 1918 } 1919 s->drain_count++; 1920 } 1921 1922 /** 1923 * Reduce .drain_count, set .was_undrained once it reaches 0. 1924 * If .drain_count reaches 0 and the node has a backing file, issue a 1925 * read request. 1926 */ 1927 static void coroutine_fn bdrv_replace_test_co_drain_end(BlockDriverState *bs) 1928 { 1929 BDRVReplaceTestState *s = bs->opaque; 1930 1931 g_assert(s->drain_count > 0); 1932 if (!--s->drain_count) { 1933 int ret; 1934 1935 s->was_undrained = true; 1936 1937 if (bs->backing) { 1938 char data; 1939 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); 1940 1941 /* Queue a read request post-drain */ 1942 ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); 1943 g_assert(ret >= 0); 1944 } 1945 } 1946 } 1947 1948 static BlockDriver bdrv_replace_test = { 1949 .format_name = "replace_test", 1950 .instance_size = sizeof(BDRVReplaceTestState), 1951 1952 .bdrv_close = bdrv_replace_test_close, 1953 .bdrv_co_preadv = bdrv_replace_test_co_preadv, 1954 1955 .bdrv_co_drain_begin = bdrv_replace_test_co_drain_begin, 1956 .bdrv_co_drain_end = bdrv_replace_test_co_drain_end, 1957 1958 .bdrv_child_perm = bdrv_default_perms, 1959 }; 1960 1961 static void coroutine_fn test_replace_child_mid_drain_read_co(void *opaque) 1962 { 1963 int ret; 1964 char data; 1965 1966 ret = blk_co_pread(opaque, 0, 1, &data, 0); 1967 g_assert(ret >= 0); 1968 } 1969 1970 /** 1971 * We test two things: 1972 * (1) bdrv_replace_child_noperm() must not undrain the parent if both 1973 * children are drained. 1974 * (2) bdrv_replace_child_noperm() must never flush I/O requests to a 1975 * drained child. If the old child is drained, it must flush I/O 1976 * requests after the new one has been attached. If the new child 1977 * is drained, it must flush I/O requests before the old one is 1978 * detached. 1979 * 1980 * To do so, we create one parent node and two child nodes; then 1981 * attach one of the children (old_child_bs) to the parent, then 1982 * drain both old_child_bs and new_child_bs according to 1983 * old_drain_count and new_drain_count, respectively, and finally 1984 * we invoke bdrv_replace_node() to replace old_child_bs by 1985 * new_child_bs. 1986 * 1987 * The test block driver we use here (bdrv_replace_test) has a read 1988 * function that: 1989 * - For the parent node, can optionally yield, and then forwards the 1990 * read to bdrv_preadv(), 1991 * - For the child node, just returns immediately. 1992 * 1993 * If the read yields, the drain_begin function will wake it up. 1994 * 1995 * The drain_end function issues a read on the parent once it is fully 1996 * undrained (which simulates requests starting to come in again). 1997 */ 1998 static void do_test_replace_child_mid_drain(int old_drain_count, 1999 int new_drain_count) 2000 { 2001 BlockBackend *parent_blk; 2002 BlockDriverState *parent_bs; 2003 BlockDriverState *old_child_bs, *new_child_bs; 2004 BDRVReplaceTestState *parent_s; 2005 BDRVReplaceTestState *old_child_s, *new_child_s; 2006 Coroutine *io_co; 2007 int i; 2008 2009 parent_bs = bdrv_new_open_driver(&bdrv_replace_test, "parent", 0, 2010 &error_abort); 2011 parent_s = parent_bs->opaque; 2012 2013 parent_blk = blk_new(qemu_get_aio_context(), 2014 BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL); 2015 blk_insert_bs(parent_blk, parent_bs, &error_abort); 2016 2017 old_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "old-child", 0, 2018 &error_abort); 2019 new_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "new-child", 0, 2020 &error_abort); 2021 old_child_s = old_child_bs->opaque; 2022 new_child_s = new_child_bs->opaque; 2023 2024 /* So that we can read something */ 2025 parent_bs->total_sectors = 1; 2026 old_child_bs->total_sectors = 1; 2027 new_child_bs->total_sectors = 1; 2028 2029 bdrv_ref(old_child_bs); 2030 parent_bs->backing = bdrv_attach_child(parent_bs, old_child_bs, "child", 2031 &child_of_bds, BDRV_CHILD_COW, 2032 &error_abort); 2033 2034 for (i = 0; i < old_drain_count; i++) { 2035 bdrv_drained_begin(old_child_bs); 2036 } 2037 for (i = 0; i < new_drain_count; i++) { 2038 bdrv_drained_begin(new_child_bs); 2039 } 2040 2041 if (!old_drain_count) { 2042 /* 2043 * Start a read operation that will yield, so it will not 2044 * complete before the node is drained. 2045 */ 2046 parent_s->yield_before_read = true; 2047 io_co = qemu_coroutine_create(test_replace_child_mid_drain_read_co, 2048 parent_blk); 2049 qemu_coroutine_enter(io_co); 2050 } 2051 2052 /* If we have started a read operation, it should have yielded */ 2053 g_assert(!parent_s->has_read); 2054 2055 /* Reset drained status so we can see what bdrv_replace_node() does */ 2056 parent_s->was_drained = false; 2057 parent_s->was_undrained = false; 2058 2059 g_assert(parent_bs->quiesce_counter == old_drain_count); 2060 bdrv_replace_node(old_child_bs, new_child_bs, &error_abort); 2061 g_assert(parent_bs->quiesce_counter == new_drain_count); 2062 2063 if (!old_drain_count && !new_drain_count) { 2064 /* 2065 * From undrained to undrained drains and undrains the parent, 2066 * because bdrv_replace_node() contains a drained section for 2067 * @old_child_bs. 2068 */ 2069 g_assert(parent_s->was_drained && parent_s->was_undrained); 2070 } else if (!old_drain_count && new_drain_count) { 2071 /* 2072 * From undrained to drained should drain the parent and keep 2073 * it that way. 2074 */ 2075 g_assert(parent_s->was_drained && !parent_s->was_undrained); 2076 } else if (old_drain_count && !new_drain_count) { 2077 /* 2078 * From drained to undrained should undrain the parent and 2079 * keep it that way. 2080 */ 2081 g_assert(!parent_s->was_drained && parent_s->was_undrained); 2082 } else /* if (old_drain_count && new_drain_count) */ { 2083 /* 2084 * From drained to drained must not undrain the parent at any 2085 * point 2086 */ 2087 g_assert(!parent_s->was_drained && !parent_s->was_undrained); 2088 } 2089 2090 if (!old_drain_count || !new_drain_count) { 2091 /* 2092 * If !old_drain_count, we have started a read request before 2093 * bdrv_replace_node(). If !new_drain_count, the parent must 2094 * have been undrained at some point, and 2095 * bdrv_replace_test_co_drain_end() starts a read request 2096 * then. 2097 */ 2098 g_assert(parent_s->has_read); 2099 } else { 2100 /* 2101 * If the parent was never undrained, there is no way to start 2102 * a read request. 2103 */ 2104 g_assert(!parent_s->has_read); 2105 } 2106 2107 /* A drained child must have not received any request */ 2108 g_assert(!(old_drain_count && old_child_s->has_read)); 2109 g_assert(!(new_drain_count && new_child_s->has_read)); 2110 2111 for (i = 0; i < new_drain_count; i++) { 2112 bdrv_drained_end(new_child_bs); 2113 } 2114 for (i = 0; i < old_drain_count; i++) { 2115 bdrv_drained_end(old_child_bs); 2116 } 2117 2118 /* 2119 * By now, bdrv_replace_test_co_drain_end() must have been called 2120 * at some point while the new child was attached to the parent. 2121 */ 2122 g_assert(parent_s->has_read); 2123 g_assert(new_child_s->has_read); 2124 2125 blk_unref(parent_blk); 2126 bdrv_unref(parent_bs); 2127 bdrv_unref(old_child_bs); 2128 bdrv_unref(new_child_bs); 2129 } 2130 2131 static void test_replace_child_mid_drain(void) 2132 { 2133 int old_drain_count, new_drain_count; 2134 2135 for (old_drain_count = 0; old_drain_count < 2; old_drain_count++) { 2136 for (new_drain_count = 0; new_drain_count < 2; new_drain_count++) { 2137 do_test_replace_child_mid_drain(old_drain_count, new_drain_count); 2138 } 2139 } 2140 } 2141 2142 int main(int argc, char **argv) 2143 { 2144 int ret; 2145 2146 bdrv_init(); 2147 qemu_init_main_loop(&error_abort); 2148 2149 g_test_init(&argc, &argv, NULL); 2150 qemu_event_init(&done_event, false); 2151 2152 g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all); 2153 g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain); 2154 g_test_add_func("/bdrv-drain/driver-cb/drain_subtree", 2155 test_drv_cb_drain_subtree); 2156 2157 g_test_add_func("/bdrv-drain/driver-cb/co/drain_all", 2158 test_drv_cb_co_drain_all); 2159 g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain); 2160 g_test_add_func("/bdrv-drain/driver-cb/co/drain_subtree", 2161 test_drv_cb_co_drain_subtree); 2162 2163 2164 g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all); 2165 g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain); 2166 g_test_add_func("/bdrv-drain/quiesce/drain_subtree", 2167 test_quiesce_drain_subtree); 2168 2169 g_test_add_func("/bdrv-drain/quiesce/co/drain_all", 2170 test_quiesce_co_drain_all); 2171 g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain); 2172 g_test_add_func("/bdrv-drain/quiesce/co/drain_subtree", 2173 test_quiesce_co_drain_subtree); 2174 2175 g_test_add_func("/bdrv-drain/nested", test_nested); 2176 g_test_add_func("/bdrv-drain/multiparent", test_multiparent); 2177 2178 g_test_add_func("/bdrv-drain/graph-change/drain_subtree", 2179 test_graph_change_drain_subtree); 2180 g_test_add_func("/bdrv-drain/graph-change/drain_all", 2181 test_graph_change_drain_all); 2182 2183 g_test_add_func("/bdrv-drain/iothread/drain_all", test_iothread_drain_all); 2184 g_test_add_func("/bdrv-drain/iothread/drain", test_iothread_drain); 2185 g_test_add_func("/bdrv-drain/iothread/drain_subtree", 2186 test_iothread_drain_subtree); 2187 2188 g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all); 2189 g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain); 2190 g_test_add_func("/bdrv-drain/blockjob/drain_subtree", 2191 test_blockjob_drain_subtree); 2192 2193 g_test_add_func("/bdrv-drain/blockjob/error/drain_all", 2194 test_blockjob_error_drain_all); 2195 g_test_add_func("/bdrv-drain/blockjob/error/drain", 2196 test_blockjob_error_drain); 2197 g_test_add_func("/bdrv-drain/blockjob/error/drain_subtree", 2198 test_blockjob_error_drain_subtree); 2199 2200 g_test_add_func("/bdrv-drain/blockjob/iothread/drain_all", 2201 test_blockjob_iothread_drain_all); 2202 g_test_add_func("/bdrv-drain/blockjob/iothread/drain", 2203 test_blockjob_iothread_drain); 2204 g_test_add_func("/bdrv-drain/blockjob/iothread/drain_subtree", 2205 test_blockjob_iothread_drain_subtree); 2206 2207 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_all", 2208 test_blockjob_iothread_error_drain_all); 2209 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain", 2210 test_blockjob_iothread_error_drain); 2211 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_subtree", 2212 test_blockjob_iothread_error_drain_subtree); 2213 2214 g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain); 2215 g_test_add_func("/bdrv-drain/detach/drain_all", test_detach_by_drain_all); 2216 g_test_add_func("/bdrv-drain/detach/drain", test_detach_by_drain); 2217 g_test_add_func("/bdrv-drain/detach/drain_subtree", test_detach_by_drain_subtree); 2218 g_test_add_func("/bdrv-drain/detach/parent_cb", test_detach_by_parent_cb); 2219 g_test_add_func("/bdrv-drain/detach/driver_cb", test_detach_by_driver_cb); 2220 2221 g_test_add_func("/bdrv-drain/attach/drain", test_append_to_drained); 2222 2223 g_test_add_func("/bdrv-drain/set_aio_context", test_set_aio_context); 2224 2225 g_test_add_func("/bdrv-drain/blockjob/commit_by_drained_end", 2226 test_blockjob_commit_by_drained_end); 2227 2228 g_test_add_func("/bdrv-drain/bdrv_drop_intermediate/poll", 2229 test_drop_intermediate_poll); 2230 2231 g_test_add_func("/bdrv-drain/replace_child/mid-drain", 2232 test_replace_child_mid_drain); 2233 2234 ret = g_test_run(); 2235 qemu_event_destroy(&done_event); 2236 return ret; 2237 } 2238