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 int run_ret; 776 int prepare_ret; 777 bool running; 778 bool should_complete; 779 } TestBlockJob; 780 781 static int test_job_prepare(Job *job) 782 { 783 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 784 785 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 786 blk_flush(s->common.blk); 787 return s->prepare_ret; 788 } 789 790 static void test_job_commit(Job *job) 791 { 792 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 793 794 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 795 blk_flush(s->common.blk); 796 } 797 798 static void test_job_abort(Job *job) 799 { 800 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 801 802 /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ 803 blk_flush(s->common.blk); 804 } 805 806 static int coroutine_fn test_job_run(Job *job, Error **errp) 807 { 808 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 809 810 /* We are running the actual job code past the pause point in 811 * job_co_entry(). */ 812 s->running = true; 813 814 job_transition_to_ready(&s->common.job); 815 while (!s->should_complete) { 816 /* Avoid job_sleep_ns() because it marks the job as !busy. We want to 817 * emulate some actual activity (probably some I/O) here so that drain 818 * has to wait for this activity to stop. */ 819 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); 820 821 job_pause_point(&s->common.job); 822 } 823 824 return s->run_ret; 825 } 826 827 static void test_job_complete(Job *job, Error **errp) 828 { 829 TestBlockJob *s = container_of(job, TestBlockJob, common.job); 830 s->should_complete = true; 831 } 832 833 BlockJobDriver test_job_driver = { 834 .job_driver = { 835 .instance_size = sizeof(TestBlockJob), 836 .free = block_job_free, 837 .user_resume = block_job_user_resume, 838 .run = test_job_run, 839 .complete = test_job_complete, 840 .prepare = test_job_prepare, 841 .commit = test_job_commit, 842 .abort = test_job_abort, 843 }, 844 }; 845 846 enum test_job_result { 847 TEST_JOB_SUCCESS, 848 TEST_JOB_FAIL_RUN, 849 TEST_JOB_FAIL_PREPARE, 850 }; 851 852 enum test_job_drain_node { 853 TEST_JOB_DRAIN_SRC, 854 TEST_JOB_DRAIN_SRC_CHILD, 855 TEST_JOB_DRAIN_SRC_PARENT, 856 }; 857 858 static void test_blockjob_common_drain_node(enum drain_type drain_type, 859 bool use_iothread, 860 enum test_job_result result, 861 enum test_job_drain_node drain_node) 862 { 863 BlockBackend *blk_src, *blk_target; 864 BlockDriverState *src, *src_backing, *src_overlay, *target, *drain_bs; 865 BlockJob *job; 866 TestBlockJob *tjob; 867 IOThread *iothread = NULL; 868 AioContext *ctx; 869 int ret; 870 871 src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR, 872 &error_abort); 873 src_backing = bdrv_new_open_driver(&bdrv_test, "source-backing", 874 BDRV_O_RDWR, &error_abort); 875 src_overlay = bdrv_new_open_driver(&bdrv_test, "source-overlay", 876 BDRV_O_RDWR, &error_abort); 877 878 bdrv_set_backing_hd(src_overlay, src, &error_abort); 879 bdrv_unref(src); 880 bdrv_set_backing_hd(src, src_backing, &error_abort); 881 bdrv_unref(src_backing); 882 883 blk_src = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 884 blk_insert_bs(blk_src, src_overlay, &error_abort); 885 886 switch (drain_node) { 887 case TEST_JOB_DRAIN_SRC: 888 drain_bs = src; 889 break; 890 case TEST_JOB_DRAIN_SRC_CHILD: 891 drain_bs = src_backing; 892 break; 893 case TEST_JOB_DRAIN_SRC_PARENT: 894 drain_bs = src_overlay; 895 break; 896 default: 897 g_assert_not_reached(); 898 } 899 900 if (use_iothread) { 901 iothread = iothread_new(); 902 ctx = iothread_get_aio_context(iothread); 903 blk_set_aio_context(blk_src, ctx, &error_abort); 904 } else { 905 ctx = qemu_get_aio_context(); 906 } 907 908 target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR, 909 &error_abort); 910 blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 911 blk_insert_bs(blk_target, target, &error_abort); 912 blk_set_allow_aio_context_change(blk_target, true); 913 914 aio_context_acquire(ctx); 915 tjob = block_job_create("job0", &test_job_driver, NULL, src, 916 0, BLK_PERM_ALL, 917 0, 0, NULL, NULL, &error_abort); 918 job = &tjob->common; 919 block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort); 920 921 switch (result) { 922 case TEST_JOB_SUCCESS: 923 break; 924 case TEST_JOB_FAIL_RUN: 925 tjob->run_ret = -EIO; 926 break; 927 case TEST_JOB_FAIL_PREPARE: 928 tjob->prepare_ret = -EIO; 929 break; 930 } 931 932 job_start(&job->job); 933 aio_context_release(ctx); 934 935 if (use_iothread) { 936 /* job_co_entry() is run in the I/O thread, wait for the actual job 937 * code to start (we don't want to catch the job in the pause point in 938 * job_co_entry(). */ 939 while (!tjob->running) { 940 aio_poll(qemu_get_aio_context(), false); 941 } 942 } 943 944 g_assert_cmpint(job->job.pause_count, ==, 0); 945 g_assert_false(job->job.paused); 946 g_assert_true(tjob->running); 947 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 948 949 do_drain_begin_unlocked(drain_type, drain_bs); 950 951 if (drain_type == BDRV_DRAIN_ALL) { 952 /* bdrv_drain_all() drains both src and target */ 953 g_assert_cmpint(job->job.pause_count, ==, 2); 954 } else { 955 g_assert_cmpint(job->job.pause_count, ==, 1); 956 } 957 g_assert_true(job->job.paused); 958 g_assert_false(job->job.busy); /* The job is paused */ 959 960 do_drain_end_unlocked(drain_type, drain_bs); 961 962 if (use_iothread) { 963 /* paused is reset in the I/O thread, wait for it */ 964 while (job->job.paused) { 965 aio_poll(qemu_get_aio_context(), false); 966 } 967 } 968 969 g_assert_cmpint(job->job.pause_count, ==, 0); 970 g_assert_false(job->job.paused); 971 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 972 973 do_drain_begin_unlocked(drain_type, target); 974 975 if (drain_type == BDRV_DRAIN_ALL) { 976 /* bdrv_drain_all() drains both src and target */ 977 g_assert_cmpint(job->job.pause_count, ==, 2); 978 } else { 979 g_assert_cmpint(job->job.pause_count, ==, 1); 980 } 981 g_assert_true(job->job.paused); 982 g_assert_false(job->job.busy); /* The job is paused */ 983 984 do_drain_end_unlocked(drain_type, target); 985 986 if (use_iothread) { 987 /* paused is reset in the I/O thread, wait for it */ 988 while (job->job.paused) { 989 aio_poll(qemu_get_aio_context(), false); 990 } 991 } 992 993 g_assert_cmpint(job->job.pause_count, ==, 0); 994 g_assert_false(job->job.paused); 995 g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ 996 997 aio_context_acquire(ctx); 998 ret = job_complete_sync(&job->job, &error_abort); 999 g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO)); 1000 1001 if (use_iothread) { 1002 blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort); 1003 assert(blk_get_aio_context(blk_target) == qemu_get_aio_context()); 1004 } 1005 aio_context_release(ctx); 1006 1007 blk_unref(blk_src); 1008 blk_unref(blk_target); 1009 bdrv_unref(src_overlay); 1010 bdrv_unref(target); 1011 1012 if (iothread) { 1013 iothread_join(iothread); 1014 } 1015 } 1016 1017 static void test_blockjob_common(enum drain_type drain_type, bool use_iothread, 1018 enum test_job_result result) 1019 { 1020 test_blockjob_common_drain_node(drain_type, use_iothread, result, 1021 TEST_JOB_DRAIN_SRC); 1022 test_blockjob_common_drain_node(drain_type, use_iothread, result, 1023 TEST_JOB_DRAIN_SRC_CHILD); 1024 if (drain_type == BDRV_SUBTREE_DRAIN) { 1025 test_blockjob_common_drain_node(drain_type, use_iothread, result, 1026 TEST_JOB_DRAIN_SRC_PARENT); 1027 } 1028 } 1029 1030 static void test_blockjob_drain_all(void) 1031 { 1032 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS); 1033 } 1034 1035 static void test_blockjob_drain(void) 1036 { 1037 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_SUCCESS); 1038 } 1039 1040 static void test_blockjob_drain_subtree(void) 1041 { 1042 test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_SUCCESS); 1043 } 1044 1045 static void test_blockjob_error_drain_all(void) 1046 { 1047 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_RUN); 1048 test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_PREPARE); 1049 } 1050 1051 static void test_blockjob_error_drain(void) 1052 { 1053 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_RUN); 1054 test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_PREPARE); 1055 } 1056 1057 static void test_blockjob_error_drain_subtree(void) 1058 { 1059 test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_RUN); 1060 test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_PREPARE); 1061 } 1062 1063 static void test_blockjob_iothread_drain_all(void) 1064 { 1065 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_SUCCESS); 1066 } 1067 1068 static void test_blockjob_iothread_drain(void) 1069 { 1070 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_SUCCESS); 1071 } 1072 1073 static void test_blockjob_iothread_drain_subtree(void) 1074 { 1075 test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_SUCCESS); 1076 } 1077 1078 static void test_blockjob_iothread_error_drain_all(void) 1079 { 1080 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_RUN); 1081 test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_PREPARE); 1082 } 1083 1084 static void test_blockjob_iothread_error_drain(void) 1085 { 1086 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_RUN); 1087 test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_PREPARE); 1088 } 1089 1090 static void test_blockjob_iothread_error_drain_subtree(void) 1091 { 1092 test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_RUN); 1093 test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_PREPARE); 1094 } 1095 1096 1097 typedef struct BDRVTestTopState { 1098 BdrvChild *wait_child; 1099 } BDRVTestTopState; 1100 1101 static void bdrv_test_top_close(BlockDriverState *bs) 1102 { 1103 BdrvChild *c, *next_c; 1104 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 1105 bdrv_unref_child(bs, c); 1106 } 1107 } 1108 1109 static int coroutine_fn bdrv_test_top_co_preadv(BlockDriverState *bs, 1110 int64_t offset, int64_t bytes, 1111 QEMUIOVector *qiov, 1112 BdrvRequestFlags flags) 1113 { 1114 BDRVTestTopState *tts = bs->opaque; 1115 return bdrv_co_preadv(tts->wait_child, offset, bytes, qiov, flags); 1116 } 1117 1118 static BlockDriver bdrv_test_top_driver = { 1119 .format_name = "test_top_driver", 1120 .instance_size = sizeof(BDRVTestTopState), 1121 1122 .bdrv_close = bdrv_test_top_close, 1123 .bdrv_co_preadv = bdrv_test_top_co_preadv, 1124 1125 .bdrv_child_perm = bdrv_default_perms, 1126 }; 1127 1128 typedef struct TestCoDeleteByDrainData { 1129 BlockBackend *blk; 1130 bool detach_instead_of_delete; 1131 bool done; 1132 } TestCoDeleteByDrainData; 1133 1134 static void coroutine_fn test_co_delete_by_drain(void *opaque) 1135 { 1136 TestCoDeleteByDrainData *dbdd = opaque; 1137 BlockBackend *blk = dbdd->blk; 1138 BlockDriverState *bs = blk_bs(blk); 1139 BDRVTestTopState *tts = bs->opaque; 1140 void *buffer = g_malloc(65536); 1141 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buffer, 65536); 1142 1143 /* Pretend some internal write operation from parent to child. 1144 * Important: We have to read from the child, not from the parent! 1145 * Draining works by first propagating it all up the tree to the 1146 * root and then waiting for drainage from root to the leaves 1147 * (protocol nodes). If we have a request waiting on the root, 1148 * everything will be drained before we go back down the tree, but 1149 * we do not want that. We want to be in the middle of draining 1150 * when this following requests returns. */ 1151 bdrv_co_preadv(tts->wait_child, 0, 65536, &qiov, 0); 1152 1153 g_assert_cmpint(bs->refcnt, ==, 1); 1154 1155 if (!dbdd->detach_instead_of_delete) { 1156 blk_unref(blk); 1157 } else { 1158 BdrvChild *c, *next_c; 1159 QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { 1160 bdrv_unref_child(bs, c); 1161 } 1162 } 1163 1164 dbdd->done = true; 1165 g_free(buffer); 1166 } 1167 1168 /** 1169 * Test what happens when some BDS has some children, you drain one of 1170 * them and this results in the BDS being deleted. 1171 * 1172 * If @detach_instead_of_delete is set, the BDS is not going to be 1173 * deleted but will only detach all of its children. 1174 */ 1175 static void do_test_delete_by_drain(bool detach_instead_of_delete, 1176 enum drain_type drain_type) 1177 { 1178 BlockBackend *blk; 1179 BlockDriverState *bs, *child_bs, *null_bs; 1180 BDRVTestTopState *tts; 1181 TestCoDeleteByDrainData dbdd; 1182 Coroutine *co; 1183 1184 bs = bdrv_new_open_driver(&bdrv_test_top_driver, "top", BDRV_O_RDWR, 1185 &error_abort); 1186 bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1187 tts = bs->opaque; 1188 1189 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1190 &error_abort); 1191 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, 1192 BDRV_CHILD_DATA, &error_abort); 1193 1194 /* This child will be the one to pass to requests through to, and 1195 * it will stall until a drain occurs */ 1196 child_bs = bdrv_new_open_driver(&bdrv_test, "child", BDRV_O_RDWR, 1197 &error_abort); 1198 child_bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; 1199 /* Takes our reference to child_bs */ 1200 tts->wait_child = bdrv_attach_child(bs, child_bs, "wait-child", 1201 &child_of_bds, 1202 BDRV_CHILD_DATA | BDRV_CHILD_PRIMARY, 1203 &error_abort); 1204 1205 /* This child is just there to be deleted 1206 * (for detach_instead_of_delete == true) */ 1207 null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1208 &error_abort); 1209 bdrv_attach_child(bs, null_bs, "null-child", &child_of_bds, BDRV_CHILD_DATA, 1210 &error_abort); 1211 1212 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1213 blk_insert_bs(blk, bs, &error_abort); 1214 1215 /* Referenced by blk now */ 1216 bdrv_unref(bs); 1217 1218 g_assert_cmpint(bs->refcnt, ==, 1); 1219 g_assert_cmpint(child_bs->refcnt, ==, 1); 1220 g_assert_cmpint(null_bs->refcnt, ==, 1); 1221 1222 1223 dbdd = (TestCoDeleteByDrainData){ 1224 .blk = blk, 1225 .detach_instead_of_delete = detach_instead_of_delete, 1226 .done = false, 1227 }; 1228 co = qemu_coroutine_create(test_co_delete_by_drain, &dbdd); 1229 qemu_coroutine_enter(co); 1230 1231 /* Drain the child while the read operation is still pending. 1232 * This should result in the operation finishing and 1233 * test_co_delete_by_drain() resuming. Thus, @bs will be deleted 1234 * and the coroutine will exit while this drain operation is still 1235 * in progress. */ 1236 switch (drain_type) { 1237 case BDRV_DRAIN: 1238 bdrv_ref(child_bs); 1239 bdrv_drain(child_bs); 1240 bdrv_unref(child_bs); 1241 break; 1242 case BDRV_SUBTREE_DRAIN: 1243 /* Would have to ref/unref bs here for !detach_instead_of_delete, but 1244 * then the whole test becomes pointless because the graph changes 1245 * don't occur during the drain any more. */ 1246 assert(detach_instead_of_delete); 1247 bdrv_subtree_drained_begin(bs); 1248 bdrv_subtree_drained_end(bs); 1249 break; 1250 case BDRV_DRAIN_ALL: 1251 bdrv_drain_all_begin(); 1252 bdrv_drain_all_end(); 1253 break; 1254 default: 1255 g_assert_not_reached(); 1256 } 1257 1258 while (!dbdd.done) { 1259 aio_poll(qemu_get_aio_context(), true); 1260 } 1261 1262 if (detach_instead_of_delete) { 1263 /* Here, the reference has not passed over to the coroutine, 1264 * so we have to delete the BB ourselves */ 1265 blk_unref(blk); 1266 } 1267 } 1268 1269 static void test_delete_by_drain(void) 1270 { 1271 do_test_delete_by_drain(false, BDRV_DRAIN); 1272 } 1273 1274 static void test_detach_by_drain_all(void) 1275 { 1276 do_test_delete_by_drain(true, BDRV_DRAIN_ALL); 1277 } 1278 1279 static void test_detach_by_drain(void) 1280 { 1281 do_test_delete_by_drain(true, BDRV_DRAIN); 1282 } 1283 1284 static void test_detach_by_drain_subtree(void) 1285 { 1286 do_test_delete_by_drain(true, BDRV_SUBTREE_DRAIN); 1287 } 1288 1289 1290 struct detach_by_parent_data { 1291 BlockDriverState *parent_b; 1292 BdrvChild *child_b; 1293 BlockDriverState *c; 1294 BdrvChild *child_c; 1295 bool by_parent_cb; 1296 }; 1297 static struct detach_by_parent_data detach_by_parent_data; 1298 1299 static void detach_indirect_bh(void *opaque) 1300 { 1301 struct detach_by_parent_data *data = opaque; 1302 1303 bdrv_unref_child(data->parent_b, data->child_b); 1304 1305 bdrv_ref(data->c); 1306 data->child_c = bdrv_attach_child(data->parent_b, data->c, "PB-C", 1307 &child_of_bds, BDRV_CHILD_DATA, 1308 &error_abort); 1309 } 1310 1311 static void detach_by_parent_aio_cb(void *opaque, int ret) 1312 { 1313 struct detach_by_parent_data *data = &detach_by_parent_data; 1314 1315 g_assert_cmpint(ret, ==, 0); 1316 if (data->by_parent_cb) { 1317 detach_indirect_bh(data); 1318 } 1319 } 1320 1321 static void detach_by_driver_cb_drained_begin(BdrvChild *child) 1322 { 1323 aio_bh_schedule_oneshot(qemu_get_current_aio_context(), 1324 detach_indirect_bh, &detach_by_parent_data); 1325 child_of_bds.drained_begin(child); 1326 } 1327 1328 static BdrvChildClass detach_by_driver_cb_class; 1329 1330 /* 1331 * Initial graph: 1332 * 1333 * PA PB 1334 * \ / \ 1335 * A B C 1336 * 1337 * by_parent_cb == true: Test that parent callbacks don't poll 1338 * 1339 * PA has a pending write request whose callback changes the child nodes of 1340 * PB: It removes B and adds C instead. The subtree of PB is drained, which 1341 * will indirectly drain the write request, too. 1342 * 1343 * by_parent_cb == false: Test that bdrv_drain_invoke() doesn't poll 1344 * 1345 * PA's BdrvChildClass has a .drained_begin callback that schedules a BH 1346 * that does the same graph change. If bdrv_drain_invoke() calls it, the 1347 * state is messed up, but if it is only polled in the single 1348 * BDRV_POLL_WHILE() at the end of the drain, this should work fine. 1349 */ 1350 static void test_detach_indirect(bool by_parent_cb) 1351 { 1352 BlockBackend *blk; 1353 BlockDriverState *parent_a, *parent_b, *a, *b, *c; 1354 BdrvChild *child_a, *child_b; 1355 BlockAIOCB *acb; 1356 1357 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); 1358 1359 if (!by_parent_cb) { 1360 detach_by_driver_cb_class = child_of_bds; 1361 detach_by_driver_cb_class.drained_begin = 1362 detach_by_driver_cb_drained_begin; 1363 } 1364 1365 /* Create all involved nodes */ 1366 parent_a = bdrv_new_open_driver(&bdrv_test, "parent-a", BDRV_O_RDWR, 1367 &error_abort); 1368 parent_b = bdrv_new_open_driver(&bdrv_test, "parent-b", 0, 1369 &error_abort); 1370 1371 a = bdrv_new_open_driver(&bdrv_test, "a", BDRV_O_RDWR, &error_abort); 1372 b = bdrv_new_open_driver(&bdrv_test, "b", BDRV_O_RDWR, &error_abort); 1373 c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort); 1374 1375 /* blk is a BB for parent-a */ 1376 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1377 blk_insert_bs(blk, parent_a, &error_abort); 1378 bdrv_unref(parent_a); 1379 1380 /* If we want to get bdrv_drain_invoke() to call aio_poll(), the driver 1381 * callback must not return immediately. */ 1382 if (!by_parent_cb) { 1383 BDRVTestState *s = parent_a->opaque; 1384 s->sleep_in_drain_begin = true; 1385 } 1386 1387 /* Set child relationships */ 1388 bdrv_ref(b); 1389 bdrv_ref(a); 1390 child_b = bdrv_attach_child(parent_b, b, "PB-B", &child_of_bds, 1391 BDRV_CHILD_DATA, &error_abort); 1392 child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_of_bds, 1393 BDRV_CHILD_COW, &error_abort); 1394 1395 bdrv_ref(a); 1396 bdrv_attach_child(parent_a, a, "PA-A", 1397 by_parent_cb ? &child_of_bds : &detach_by_driver_cb_class, 1398 BDRV_CHILD_DATA, &error_abort); 1399 1400 g_assert_cmpint(parent_a->refcnt, ==, 1); 1401 g_assert_cmpint(parent_b->refcnt, ==, 1); 1402 g_assert_cmpint(a->refcnt, ==, 3); 1403 g_assert_cmpint(b->refcnt, ==, 2); 1404 g_assert_cmpint(c->refcnt, ==, 1); 1405 1406 g_assert(QLIST_FIRST(&parent_b->children) == child_a); 1407 g_assert(QLIST_NEXT(child_a, next) == child_b); 1408 g_assert(QLIST_NEXT(child_b, next) == NULL); 1409 1410 /* Start the evil write request */ 1411 detach_by_parent_data = (struct detach_by_parent_data) { 1412 .parent_b = parent_b, 1413 .child_b = child_b, 1414 .c = c, 1415 .by_parent_cb = by_parent_cb, 1416 }; 1417 acb = blk_aio_preadv(blk, 0, &qiov, 0, detach_by_parent_aio_cb, NULL); 1418 g_assert(acb != NULL); 1419 1420 /* Drain and check the expected result */ 1421 bdrv_subtree_drained_begin(parent_b); 1422 1423 g_assert(detach_by_parent_data.child_c != NULL); 1424 1425 g_assert_cmpint(parent_a->refcnt, ==, 1); 1426 g_assert_cmpint(parent_b->refcnt, ==, 1); 1427 g_assert_cmpint(a->refcnt, ==, 3); 1428 g_assert_cmpint(b->refcnt, ==, 1); 1429 g_assert_cmpint(c->refcnt, ==, 2); 1430 1431 g_assert(QLIST_FIRST(&parent_b->children) == detach_by_parent_data.child_c); 1432 g_assert(QLIST_NEXT(detach_by_parent_data.child_c, next) == child_a); 1433 g_assert(QLIST_NEXT(child_a, next) == NULL); 1434 1435 g_assert_cmpint(parent_a->quiesce_counter, ==, 1); 1436 g_assert_cmpint(parent_b->quiesce_counter, ==, 1); 1437 g_assert_cmpint(a->quiesce_counter, ==, 1); 1438 g_assert_cmpint(b->quiesce_counter, ==, 0); 1439 g_assert_cmpint(c->quiesce_counter, ==, 1); 1440 1441 bdrv_subtree_drained_end(parent_b); 1442 1443 bdrv_unref(parent_b); 1444 blk_unref(blk); 1445 1446 g_assert_cmpint(a->refcnt, ==, 1); 1447 g_assert_cmpint(b->refcnt, ==, 1); 1448 g_assert_cmpint(c->refcnt, ==, 1); 1449 bdrv_unref(a); 1450 bdrv_unref(b); 1451 bdrv_unref(c); 1452 } 1453 1454 static void test_detach_by_parent_cb(void) 1455 { 1456 test_detach_indirect(true); 1457 } 1458 1459 static void test_detach_by_driver_cb(void) 1460 { 1461 test_detach_indirect(false); 1462 } 1463 1464 static void test_append_to_drained(void) 1465 { 1466 BlockBackend *blk; 1467 BlockDriverState *base, *overlay; 1468 BDRVTestState *base_s, *overlay_s; 1469 1470 blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); 1471 base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort); 1472 base_s = base->opaque; 1473 blk_insert_bs(blk, base, &error_abort); 1474 1475 overlay = bdrv_new_open_driver(&bdrv_test, "overlay", BDRV_O_RDWR, 1476 &error_abort); 1477 overlay_s = overlay->opaque; 1478 1479 do_drain_begin(BDRV_DRAIN, base); 1480 g_assert_cmpint(base->quiesce_counter, ==, 1); 1481 g_assert_cmpint(base_s->drain_count, ==, 1); 1482 g_assert_cmpint(base->in_flight, ==, 0); 1483 1484 bdrv_append(overlay, base, &error_abort); 1485 g_assert_cmpint(base->in_flight, ==, 0); 1486 g_assert_cmpint(overlay->in_flight, ==, 0); 1487 1488 g_assert_cmpint(base->quiesce_counter, ==, 1); 1489 g_assert_cmpint(base_s->drain_count, ==, 1); 1490 g_assert_cmpint(overlay->quiesce_counter, ==, 1); 1491 g_assert_cmpint(overlay_s->drain_count, ==, 1); 1492 1493 do_drain_end(BDRV_DRAIN, base); 1494 1495 g_assert_cmpint(base->quiesce_counter, ==, 0); 1496 g_assert_cmpint(base_s->drain_count, ==, 0); 1497 g_assert_cmpint(overlay->quiesce_counter, ==, 0); 1498 g_assert_cmpint(overlay_s->drain_count, ==, 0); 1499 1500 bdrv_unref(overlay); 1501 bdrv_unref(base); 1502 blk_unref(blk); 1503 } 1504 1505 static void test_set_aio_context(void) 1506 { 1507 BlockDriverState *bs; 1508 IOThread *a = iothread_new(); 1509 IOThread *b = iothread_new(); 1510 AioContext *ctx_a = iothread_get_aio_context(a); 1511 AioContext *ctx_b = iothread_get_aio_context(b); 1512 1513 bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, 1514 &error_abort); 1515 1516 bdrv_drained_begin(bs); 1517 bdrv_try_set_aio_context(bs, ctx_a, &error_abort); 1518 1519 aio_context_acquire(ctx_a); 1520 bdrv_drained_end(bs); 1521 1522 bdrv_drained_begin(bs); 1523 bdrv_try_set_aio_context(bs, ctx_b, &error_abort); 1524 aio_context_release(ctx_a); 1525 aio_context_acquire(ctx_b); 1526 bdrv_try_set_aio_context(bs, qemu_get_aio_context(), &error_abort); 1527 aio_context_release(ctx_b); 1528 bdrv_drained_end(bs); 1529 1530 bdrv_unref(bs); 1531 iothread_join(a); 1532 iothread_join(b); 1533 } 1534 1535 1536 typedef struct TestDropBackingBlockJob { 1537 BlockJob common; 1538 bool should_complete; 1539 bool *did_complete; 1540 BlockDriverState *detach_also; 1541 } TestDropBackingBlockJob; 1542 1543 static int coroutine_fn test_drop_backing_job_run(Job *job, Error **errp) 1544 { 1545 TestDropBackingBlockJob *s = 1546 container_of(job, TestDropBackingBlockJob, common.job); 1547 1548 while (!s->should_complete) { 1549 job_sleep_ns(job, 0); 1550 } 1551 1552 return 0; 1553 } 1554 1555 static void test_drop_backing_job_commit(Job *job) 1556 { 1557 TestDropBackingBlockJob *s = 1558 container_of(job, TestDropBackingBlockJob, common.job); 1559 1560 bdrv_set_backing_hd(blk_bs(s->common.blk), NULL, &error_abort); 1561 bdrv_set_backing_hd(s->detach_also, NULL, &error_abort); 1562 1563 *s->did_complete = true; 1564 } 1565 1566 static const BlockJobDriver test_drop_backing_job_driver = { 1567 .job_driver = { 1568 .instance_size = sizeof(TestDropBackingBlockJob), 1569 .free = block_job_free, 1570 .user_resume = block_job_user_resume, 1571 .run = test_drop_backing_job_run, 1572 .commit = test_drop_backing_job_commit, 1573 } 1574 }; 1575 1576 /** 1577 * Creates a child node with three parent nodes on it, and then runs a 1578 * block job on the final one, parent-node-2. 1579 * 1580 * The job is then asked to complete before a section where the child 1581 * is drained. 1582 * 1583 * Ending this section will undrain the child's parents, first 1584 * parent-node-2, then parent-node-1, then parent-node-0 -- the parent 1585 * list is in reverse order of how they were added. Ending the drain 1586 * on parent-node-2 will resume the job, thus completing it and 1587 * scheduling job_exit(). 1588 * 1589 * Ending the drain on parent-node-1 will poll the AioContext, which 1590 * lets job_exit() and thus test_drop_backing_job_commit() run. That 1591 * function first removes the child as parent-node-2's backing file. 1592 * 1593 * In old (and buggy) implementations, there are two problems with 1594 * that: 1595 * (A) bdrv_drain_invoke() polls for every node that leaves the 1596 * drained section. This means that job_exit() is scheduled 1597 * before the child has left the drained section. Its 1598 * quiesce_counter is therefore still 1 when it is removed from 1599 * parent-node-2. 1600 * 1601 * (B) bdrv_replace_child_noperm() calls drained_end() on the old 1602 * child's parents as many times as the child is quiesced. This 1603 * means it will call drained_end() on parent-node-2 once. 1604 * Because parent-node-2 is no longer quiesced at this point, this 1605 * will fail. 1606 * 1607 * bdrv_replace_child_noperm() therefore must call drained_end() on 1608 * the parent only if it really is still drained because the child is 1609 * drained. 1610 * 1611 * If removing child from parent-node-2 was successful (as it should 1612 * be), test_drop_backing_job_commit() will then also remove the child 1613 * from parent-node-0. 1614 * 1615 * With an old version of our drain infrastructure ((A) above), that 1616 * resulted in the following flow: 1617 * 1618 * 1. child attempts to leave its drained section. The call recurses 1619 * to its parents. 1620 * 1621 * 2. parent-node-2 leaves the drained section. Polling in 1622 * bdrv_drain_invoke() will schedule job_exit(). 1623 * 1624 * 3. parent-node-1 leaves the drained section. Polling in 1625 * bdrv_drain_invoke() will run job_exit(), thus disconnecting 1626 * parent-node-0 from the child node. 1627 * 1628 * 4. bdrv_parent_drained_end() uses a QLIST_FOREACH_SAFE() loop to 1629 * iterate over the parents. Thus, it now accesses the BdrvChild 1630 * object that used to connect parent-node-0 and the child node. 1631 * However, that object no longer exists, so it accesses a dangling 1632 * pointer. 1633 * 1634 * The solution is to only poll once when running a bdrv_drained_end() 1635 * operation, specifically at the end when all drained_end() 1636 * operations for all involved nodes have been scheduled. 1637 * Note that this also solves (A) above, thus hiding (B). 1638 */ 1639 static void test_blockjob_commit_by_drained_end(void) 1640 { 1641 BlockDriverState *bs_child, *bs_parents[3]; 1642 TestDropBackingBlockJob *job; 1643 bool job_has_completed = false; 1644 int i; 1645 1646 bs_child = bdrv_new_open_driver(&bdrv_test, "child-node", BDRV_O_RDWR, 1647 &error_abort); 1648 1649 for (i = 0; i < 3; i++) { 1650 char name[32]; 1651 snprintf(name, sizeof(name), "parent-node-%i", i); 1652 bs_parents[i] = bdrv_new_open_driver(&bdrv_test, name, BDRV_O_RDWR, 1653 &error_abort); 1654 bdrv_set_backing_hd(bs_parents[i], bs_child, &error_abort); 1655 } 1656 1657 job = block_job_create("job", &test_drop_backing_job_driver, NULL, 1658 bs_parents[2], 0, BLK_PERM_ALL, 0, 0, NULL, NULL, 1659 &error_abort); 1660 1661 job->detach_also = bs_parents[0]; 1662 job->did_complete = &job_has_completed; 1663 1664 job_start(&job->common.job); 1665 1666 job->should_complete = true; 1667 bdrv_drained_begin(bs_child); 1668 g_assert(!job_has_completed); 1669 bdrv_drained_end(bs_child); 1670 g_assert(job_has_completed); 1671 1672 bdrv_unref(bs_parents[0]); 1673 bdrv_unref(bs_parents[1]); 1674 bdrv_unref(bs_parents[2]); 1675 bdrv_unref(bs_child); 1676 } 1677 1678 1679 typedef struct TestSimpleBlockJob { 1680 BlockJob common; 1681 bool should_complete; 1682 bool *did_complete; 1683 } TestSimpleBlockJob; 1684 1685 static int coroutine_fn test_simple_job_run(Job *job, Error **errp) 1686 { 1687 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1688 1689 while (!s->should_complete) { 1690 job_sleep_ns(job, 0); 1691 } 1692 1693 return 0; 1694 } 1695 1696 static void test_simple_job_clean(Job *job) 1697 { 1698 TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job); 1699 *s->did_complete = true; 1700 } 1701 1702 static const BlockJobDriver test_simple_job_driver = { 1703 .job_driver = { 1704 .instance_size = sizeof(TestSimpleBlockJob), 1705 .free = block_job_free, 1706 .user_resume = block_job_user_resume, 1707 .run = test_simple_job_run, 1708 .clean = test_simple_job_clean, 1709 }, 1710 }; 1711 1712 static int drop_intermediate_poll_update_filename(BdrvChild *child, 1713 BlockDriverState *new_base, 1714 const char *filename, 1715 Error **errp) 1716 { 1717 /* 1718 * We are free to poll here, which may change the block graph, if 1719 * it is not drained. 1720 */ 1721 1722 /* If the job is not drained: Complete it, schedule job_exit() */ 1723 aio_poll(qemu_get_current_aio_context(), false); 1724 /* If the job is not drained: Run job_exit(), finish the job */ 1725 aio_poll(qemu_get_current_aio_context(), false); 1726 1727 return 0; 1728 } 1729 1730 /** 1731 * Test a poll in the midst of bdrv_drop_intermediate(). 1732 * 1733 * bdrv_drop_intermediate() calls BdrvChildClass.update_filename(), 1734 * which can yield or poll. This may lead to graph changes, unless 1735 * the whole subtree in question is drained. 1736 * 1737 * We test this on the following graph: 1738 * 1739 * Job 1740 * 1741 * | 1742 * job-node 1743 * | 1744 * v 1745 * 1746 * job-node 1747 * 1748 * | 1749 * backing 1750 * | 1751 * v 1752 * 1753 * node-2 --chain--> node-1 --chain--> node-0 1754 * 1755 * We drop node-1 with bdrv_drop_intermediate(top=node-1, base=node-0). 1756 * 1757 * This first updates node-2's backing filename by invoking 1758 * drop_intermediate_poll_update_filename(), which polls twice. This 1759 * causes the job to finish, which in turns causes the job-node to be 1760 * deleted. 1761 * 1762 * bdrv_drop_intermediate() uses a QLIST_FOREACH_SAFE() loop, so it 1763 * already has a pointer to the BdrvChild edge between job-node and 1764 * node-1. When it tries to handle that edge, we probably get a 1765 * segmentation fault because the object no longer exists. 1766 * 1767 * 1768 * The solution is for bdrv_drop_intermediate() to drain top's 1769 * subtree. This prevents graph changes from happening just because 1770 * BdrvChildClass.update_filename() yields or polls. Thus, the block 1771 * job is paused during that drained section and must finish before or 1772 * after. 1773 * 1774 * (In addition, bdrv_replace_child() must keep the job paused.) 1775 */ 1776 static void test_drop_intermediate_poll(void) 1777 { 1778 static BdrvChildClass chain_child_class; 1779 BlockDriverState *chain[3]; 1780 TestSimpleBlockJob *job; 1781 BlockDriverState *job_node; 1782 bool job_has_completed = false; 1783 int i; 1784 int ret; 1785 1786 chain_child_class = child_of_bds; 1787 chain_child_class.update_filename = drop_intermediate_poll_update_filename; 1788 1789 for (i = 0; i < 3; i++) { 1790 char name[32]; 1791 snprintf(name, 32, "node-%i", i); 1792 1793 chain[i] = bdrv_new_open_driver(&bdrv_test, name, 0, &error_abort); 1794 } 1795 1796 job_node = bdrv_new_open_driver(&bdrv_test, "job-node", BDRV_O_RDWR, 1797 &error_abort); 1798 bdrv_set_backing_hd(job_node, chain[1], &error_abort); 1799 1800 /* 1801 * Establish the chain last, so the chain links are the first 1802 * elements in the BDS.parents lists 1803 */ 1804 for (i = 0; i < 3; i++) { 1805 if (i) { 1806 /* Takes the reference to chain[i - 1] */ 1807 chain[i]->backing = bdrv_attach_child(chain[i], chain[i - 1], 1808 "chain", &chain_child_class, 1809 BDRV_CHILD_COW, &error_abort); 1810 } 1811 } 1812 1813 job = block_job_create("job", &test_simple_job_driver, NULL, job_node, 1814 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort); 1815 1816 /* The job has a reference now */ 1817 bdrv_unref(job_node); 1818 1819 job->did_complete = &job_has_completed; 1820 1821 job_start(&job->common.job); 1822 job->should_complete = true; 1823 1824 g_assert(!job_has_completed); 1825 ret = bdrv_drop_intermediate(chain[1], chain[0], NULL); 1826 g_assert(ret == 0); 1827 g_assert(job_has_completed); 1828 1829 bdrv_unref(chain[2]); 1830 } 1831 1832 1833 typedef struct BDRVReplaceTestState { 1834 bool was_drained; 1835 bool was_undrained; 1836 bool has_read; 1837 1838 int drain_count; 1839 1840 bool yield_before_read; 1841 Coroutine *io_co; 1842 Coroutine *drain_co; 1843 } BDRVReplaceTestState; 1844 1845 static void bdrv_replace_test_close(BlockDriverState *bs) 1846 { 1847 } 1848 1849 /** 1850 * If @bs has a backing file: 1851 * Yield if .yield_before_read is true (and wait for drain_begin to 1852 * wake us up). 1853 * Forward the read to bs->backing. Set .has_read to true. 1854 * If drain_begin has woken us, wake it in turn. 1855 * 1856 * Otherwise: 1857 * Set .has_read to true and return success. 1858 */ 1859 static int coroutine_fn bdrv_replace_test_co_preadv(BlockDriverState *bs, 1860 int64_t offset, 1861 int64_t bytes, 1862 QEMUIOVector *qiov, 1863 BdrvRequestFlags flags) 1864 { 1865 BDRVReplaceTestState *s = bs->opaque; 1866 1867 if (bs->backing) { 1868 int ret; 1869 1870 g_assert(!s->drain_count); 1871 1872 s->io_co = qemu_coroutine_self(); 1873 if (s->yield_before_read) { 1874 s->yield_before_read = false; 1875 qemu_coroutine_yield(); 1876 } 1877 s->io_co = NULL; 1878 1879 ret = bdrv_co_preadv(bs->backing, offset, bytes, qiov, 0); 1880 s->has_read = true; 1881 1882 /* Wake up drain_co if it runs */ 1883 if (s->drain_co) { 1884 aio_co_wake(s->drain_co); 1885 } 1886 1887 return ret; 1888 } 1889 1890 s->has_read = true; 1891 return 0; 1892 } 1893 1894 /** 1895 * If .drain_count is 0, wake up .io_co if there is one; and set 1896 * .was_drained. 1897 * Increment .drain_count. 1898 */ 1899 static void coroutine_fn bdrv_replace_test_co_drain_begin(BlockDriverState *bs) 1900 { 1901 BDRVReplaceTestState *s = bs->opaque; 1902 1903 if (!s->drain_count) { 1904 /* Keep waking io_co up until it is done */ 1905 s->drain_co = qemu_coroutine_self(); 1906 while (s->io_co) { 1907 aio_co_wake(s->io_co); 1908 s->io_co = NULL; 1909 qemu_coroutine_yield(); 1910 } 1911 s->drain_co = NULL; 1912 1913 s->was_drained = true; 1914 } 1915 s->drain_count++; 1916 } 1917 1918 /** 1919 * Reduce .drain_count, set .was_undrained once it reaches 0. 1920 * If .drain_count reaches 0 and the node has a backing file, issue a 1921 * read request. 1922 */ 1923 static void coroutine_fn bdrv_replace_test_co_drain_end(BlockDriverState *bs) 1924 { 1925 BDRVReplaceTestState *s = bs->opaque; 1926 1927 g_assert(s->drain_count > 0); 1928 if (!--s->drain_count) { 1929 int ret; 1930 1931 s->was_undrained = true; 1932 1933 if (bs->backing) { 1934 char data; 1935 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); 1936 1937 /* Queue a read request post-drain */ 1938 ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); 1939 g_assert(ret >= 0); 1940 } 1941 } 1942 } 1943 1944 static BlockDriver bdrv_replace_test = { 1945 .format_name = "replace_test", 1946 .instance_size = sizeof(BDRVReplaceTestState), 1947 1948 .bdrv_close = bdrv_replace_test_close, 1949 .bdrv_co_preadv = bdrv_replace_test_co_preadv, 1950 1951 .bdrv_co_drain_begin = bdrv_replace_test_co_drain_begin, 1952 .bdrv_co_drain_end = bdrv_replace_test_co_drain_end, 1953 1954 .bdrv_child_perm = bdrv_default_perms, 1955 }; 1956 1957 static void coroutine_fn test_replace_child_mid_drain_read_co(void *opaque) 1958 { 1959 int ret; 1960 char data; 1961 1962 ret = blk_co_pread(opaque, 0, 1, &data, 0); 1963 g_assert(ret >= 0); 1964 } 1965 1966 /** 1967 * We test two things: 1968 * (1) bdrv_replace_child_noperm() must not undrain the parent if both 1969 * children are drained. 1970 * (2) bdrv_replace_child_noperm() must never flush I/O requests to a 1971 * drained child. If the old child is drained, it must flush I/O 1972 * requests after the new one has been attached. If the new child 1973 * is drained, it must flush I/O requests before the old one is 1974 * detached. 1975 * 1976 * To do so, we create one parent node and two child nodes; then 1977 * attach one of the children (old_child_bs) to the parent, then 1978 * drain both old_child_bs and new_child_bs according to 1979 * old_drain_count and new_drain_count, respectively, and finally 1980 * we invoke bdrv_replace_node() to replace old_child_bs by 1981 * new_child_bs. 1982 * 1983 * The test block driver we use here (bdrv_replace_test) has a read 1984 * function that: 1985 * - For the parent node, can optionally yield, and then forwards the 1986 * read to bdrv_preadv(), 1987 * - For the child node, just returns immediately. 1988 * 1989 * If the read yields, the drain_begin function will wake it up. 1990 * 1991 * The drain_end function issues a read on the parent once it is fully 1992 * undrained (which simulates requests starting to come in again). 1993 */ 1994 static void do_test_replace_child_mid_drain(int old_drain_count, 1995 int new_drain_count) 1996 { 1997 BlockBackend *parent_blk; 1998 BlockDriverState *parent_bs; 1999 BlockDriverState *old_child_bs, *new_child_bs; 2000 BDRVReplaceTestState *parent_s; 2001 BDRVReplaceTestState *old_child_s, *new_child_s; 2002 Coroutine *io_co; 2003 int i; 2004 2005 parent_bs = bdrv_new_open_driver(&bdrv_replace_test, "parent", 0, 2006 &error_abort); 2007 parent_s = parent_bs->opaque; 2008 2009 parent_blk = blk_new(qemu_get_aio_context(), 2010 BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL); 2011 blk_insert_bs(parent_blk, parent_bs, &error_abort); 2012 2013 old_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "old-child", 0, 2014 &error_abort); 2015 new_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "new-child", 0, 2016 &error_abort); 2017 old_child_s = old_child_bs->opaque; 2018 new_child_s = new_child_bs->opaque; 2019 2020 /* So that we can read something */ 2021 parent_bs->total_sectors = 1; 2022 old_child_bs->total_sectors = 1; 2023 new_child_bs->total_sectors = 1; 2024 2025 bdrv_ref(old_child_bs); 2026 parent_bs->backing = bdrv_attach_child(parent_bs, old_child_bs, "child", 2027 &child_of_bds, BDRV_CHILD_COW, 2028 &error_abort); 2029 2030 for (i = 0; i < old_drain_count; i++) { 2031 bdrv_drained_begin(old_child_bs); 2032 } 2033 for (i = 0; i < new_drain_count; i++) { 2034 bdrv_drained_begin(new_child_bs); 2035 } 2036 2037 if (!old_drain_count) { 2038 /* 2039 * Start a read operation that will yield, so it will not 2040 * complete before the node is drained. 2041 */ 2042 parent_s->yield_before_read = true; 2043 io_co = qemu_coroutine_create(test_replace_child_mid_drain_read_co, 2044 parent_blk); 2045 qemu_coroutine_enter(io_co); 2046 } 2047 2048 /* If we have started a read operation, it should have yielded */ 2049 g_assert(!parent_s->has_read); 2050 2051 /* Reset drained status so we can see what bdrv_replace_node() does */ 2052 parent_s->was_drained = false; 2053 parent_s->was_undrained = false; 2054 2055 g_assert(parent_bs->quiesce_counter == old_drain_count); 2056 bdrv_replace_node(old_child_bs, new_child_bs, &error_abort); 2057 g_assert(parent_bs->quiesce_counter == new_drain_count); 2058 2059 if (!old_drain_count && !new_drain_count) { 2060 /* 2061 * From undrained to undrained drains and undrains the parent, 2062 * because bdrv_replace_node() contains a drained section for 2063 * @old_child_bs. 2064 */ 2065 g_assert(parent_s->was_drained && parent_s->was_undrained); 2066 } else if (!old_drain_count && new_drain_count) { 2067 /* 2068 * From undrained to drained should drain the parent and keep 2069 * it that way. 2070 */ 2071 g_assert(parent_s->was_drained && !parent_s->was_undrained); 2072 } else if (old_drain_count && !new_drain_count) { 2073 /* 2074 * From drained to undrained should undrain the parent and 2075 * keep it that way. 2076 */ 2077 g_assert(!parent_s->was_drained && parent_s->was_undrained); 2078 } else /* if (old_drain_count && new_drain_count) */ { 2079 /* 2080 * From drained to drained must not undrain the parent at any 2081 * point 2082 */ 2083 g_assert(!parent_s->was_drained && !parent_s->was_undrained); 2084 } 2085 2086 if (!old_drain_count || !new_drain_count) { 2087 /* 2088 * If !old_drain_count, we have started a read request before 2089 * bdrv_replace_node(). If !new_drain_count, the parent must 2090 * have been undrained at some point, and 2091 * bdrv_replace_test_co_drain_end() starts a read request 2092 * then. 2093 */ 2094 g_assert(parent_s->has_read); 2095 } else { 2096 /* 2097 * If the parent was never undrained, there is no way to start 2098 * a read request. 2099 */ 2100 g_assert(!parent_s->has_read); 2101 } 2102 2103 /* A drained child must have not received any request */ 2104 g_assert(!(old_drain_count && old_child_s->has_read)); 2105 g_assert(!(new_drain_count && new_child_s->has_read)); 2106 2107 for (i = 0; i < new_drain_count; i++) { 2108 bdrv_drained_end(new_child_bs); 2109 } 2110 for (i = 0; i < old_drain_count; i++) { 2111 bdrv_drained_end(old_child_bs); 2112 } 2113 2114 /* 2115 * By now, bdrv_replace_test_co_drain_end() must have been called 2116 * at some point while the new child was attached to the parent. 2117 */ 2118 g_assert(parent_s->has_read); 2119 g_assert(new_child_s->has_read); 2120 2121 blk_unref(parent_blk); 2122 bdrv_unref(parent_bs); 2123 bdrv_unref(old_child_bs); 2124 bdrv_unref(new_child_bs); 2125 } 2126 2127 static void test_replace_child_mid_drain(void) 2128 { 2129 int old_drain_count, new_drain_count; 2130 2131 for (old_drain_count = 0; old_drain_count < 2; old_drain_count++) { 2132 for (new_drain_count = 0; new_drain_count < 2; new_drain_count++) { 2133 do_test_replace_child_mid_drain(old_drain_count, new_drain_count); 2134 } 2135 } 2136 } 2137 2138 int main(int argc, char **argv) 2139 { 2140 int ret; 2141 2142 bdrv_init(); 2143 qemu_init_main_loop(&error_abort); 2144 2145 g_test_init(&argc, &argv, NULL); 2146 qemu_event_init(&done_event, false); 2147 2148 g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all); 2149 g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain); 2150 g_test_add_func("/bdrv-drain/driver-cb/drain_subtree", 2151 test_drv_cb_drain_subtree); 2152 2153 g_test_add_func("/bdrv-drain/driver-cb/co/drain_all", 2154 test_drv_cb_co_drain_all); 2155 g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain); 2156 g_test_add_func("/bdrv-drain/driver-cb/co/drain_subtree", 2157 test_drv_cb_co_drain_subtree); 2158 2159 2160 g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all); 2161 g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain); 2162 g_test_add_func("/bdrv-drain/quiesce/drain_subtree", 2163 test_quiesce_drain_subtree); 2164 2165 g_test_add_func("/bdrv-drain/quiesce/co/drain_all", 2166 test_quiesce_co_drain_all); 2167 g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain); 2168 g_test_add_func("/bdrv-drain/quiesce/co/drain_subtree", 2169 test_quiesce_co_drain_subtree); 2170 2171 g_test_add_func("/bdrv-drain/nested", test_nested); 2172 g_test_add_func("/bdrv-drain/multiparent", test_multiparent); 2173 2174 g_test_add_func("/bdrv-drain/graph-change/drain_subtree", 2175 test_graph_change_drain_subtree); 2176 g_test_add_func("/bdrv-drain/graph-change/drain_all", 2177 test_graph_change_drain_all); 2178 2179 g_test_add_func("/bdrv-drain/iothread/drain_all", test_iothread_drain_all); 2180 g_test_add_func("/bdrv-drain/iothread/drain", test_iothread_drain); 2181 g_test_add_func("/bdrv-drain/iothread/drain_subtree", 2182 test_iothread_drain_subtree); 2183 2184 g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all); 2185 g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain); 2186 g_test_add_func("/bdrv-drain/blockjob/drain_subtree", 2187 test_blockjob_drain_subtree); 2188 2189 g_test_add_func("/bdrv-drain/blockjob/error/drain_all", 2190 test_blockjob_error_drain_all); 2191 g_test_add_func("/bdrv-drain/blockjob/error/drain", 2192 test_blockjob_error_drain); 2193 g_test_add_func("/bdrv-drain/blockjob/error/drain_subtree", 2194 test_blockjob_error_drain_subtree); 2195 2196 g_test_add_func("/bdrv-drain/blockjob/iothread/drain_all", 2197 test_blockjob_iothread_drain_all); 2198 g_test_add_func("/bdrv-drain/blockjob/iothread/drain", 2199 test_blockjob_iothread_drain); 2200 g_test_add_func("/bdrv-drain/blockjob/iothread/drain_subtree", 2201 test_blockjob_iothread_drain_subtree); 2202 2203 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_all", 2204 test_blockjob_iothread_error_drain_all); 2205 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain", 2206 test_blockjob_iothread_error_drain); 2207 g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_subtree", 2208 test_blockjob_iothread_error_drain_subtree); 2209 2210 g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain); 2211 g_test_add_func("/bdrv-drain/detach/drain_all", test_detach_by_drain_all); 2212 g_test_add_func("/bdrv-drain/detach/drain", test_detach_by_drain); 2213 g_test_add_func("/bdrv-drain/detach/drain_subtree", test_detach_by_drain_subtree); 2214 g_test_add_func("/bdrv-drain/detach/parent_cb", test_detach_by_parent_cb); 2215 g_test_add_func("/bdrv-drain/detach/driver_cb", test_detach_by_driver_cb); 2216 2217 g_test_add_func("/bdrv-drain/attach/drain", test_append_to_drained); 2218 2219 g_test_add_func("/bdrv-drain/set_aio_context", test_set_aio_context); 2220 2221 g_test_add_func("/bdrv-drain/blockjob/commit_by_drained_end", 2222 test_blockjob_commit_by_drained_end); 2223 2224 g_test_add_func("/bdrv-drain/bdrv_drop_intermediate/poll", 2225 test_drop_intermediate_poll); 2226 2227 g_test_add_func("/bdrv-drain/replace_child/mid-drain", 2228 test_replace_child_mid_drain); 2229 2230 ret = g_test_run(); 2231 qemu_event_destroy(&done_event); 2232 return ret; 2233 } 2234