/* * Block node draining tests * * Copyright (c) 2017 Kevin Wolf * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "qemu/osdep.h" #include "block/block.h" #include "block/blockjob_int.h" #include "sysemu/block-backend.h" #include "qapi/error.h" #include "iothread.h" static QemuEvent done_event; typedef struct BDRVTestState { int drain_count; AioContext *bh_indirection_ctx; bool sleep_in_drain_begin; } BDRVTestState; static void coroutine_fn bdrv_test_co_drain_begin(BlockDriverState *bs) { BDRVTestState *s = bs->opaque; s->drain_count++; if (s->sleep_in_drain_begin) { qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000); } } static void coroutine_fn bdrv_test_co_drain_end(BlockDriverState *bs) { BDRVTestState *s = bs->opaque; s->drain_count--; } static void bdrv_test_close(BlockDriverState *bs) { BDRVTestState *s = bs->opaque; g_assert_cmpint(s->drain_count, >, 0); } static void co_reenter_bh(void *opaque) { aio_co_wake(opaque); } static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { BDRVTestState *s = bs->opaque; /* We want this request to stay until the polling loop in drain waits for * it to complete. We need to sleep a while as bdrv_drain_invoke() comes * first and polls its result, too, but it shouldn't accidentally complete * this request yet. */ qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000); if (s->bh_indirection_ctx) { aio_bh_schedule_oneshot(s->bh_indirection_ctx, co_reenter_bh, qemu_coroutine_self()); qemu_coroutine_yield(); } return 0; } static void bdrv_test_child_perm(BlockDriverState *bs, BdrvChild *c, const BdrvChildRole *role, BlockReopenQueue *reopen_queue, uint64_t perm, uint64_t shared, uint64_t *nperm, uint64_t *nshared) { /* bdrv_format_default_perms() accepts only these two, so disguise * detach_by_driver_cb_role as one of them. */ if (role != &child_file && role != &child_backing) { role = &child_file; } bdrv_format_default_perms(bs, c, role, reopen_queue, perm, shared, nperm, nshared); } static BlockDriver bdrv_test = { .format_name = "test", .instance_size = sizeof(BDRVTestState), .bdrv_close = bdrv_test_close, .bdrv_co_preadv = bdrv_test_co_preadv, .bdrv_co_drain_begin = bdrv_test_co_drain_begin, .bdrv_co_drain_end = bdrv_test_co_drain_end, .bdrv_child_perm = bdrv_test_child_perm, }; static void aio_ret_cb(void *opaque, int ret) { int *aio_ret = opaque; *aio_ret = ret; } typedef struct CallInCoroutineData { void (*entry)(void); bool done; } CallInCoroutineData; static coroutine_fn void call_in_coroutine_entry(void *opaque) { CallInCoroutineData *data = opaque; data->entry(); data->done = true; } static void call_in_coroutine(void (*entry)(void)) { Coroutine *co; CallInCoroutineData data = { .entry = entry, .done = false, }; co = qemu_coroutine_create(call_in_coroutine_entry, &data); qemu_coroutine_enter(co); while (!data.done) { aio_poll(qemu_get_aio_context(), true); } } enum drain_type { BDRV_DRAIN_ALL, BDRV_DRAIN, BDRV_SUBTREE_DRAIN, DRAIN_TYPE_MAX, }; static void do_drain_begin(enum drain_type drain_type, BlockDriverState *bs) { switch (drain_type) { case BDRV_DRAIN_ALL: bdrv_drain_all_begin(); break; case BDRV_DRAIN: bdrv_drained_begin(bs); break; case BDRV_SUBTREE_DRAIN: bdrv_subtree_drained_begin(bs); break; default: g_assert_not_reached(); } } static void do_drain_end(enum drain_type drain_type, BlockDriverState *bs) { switch (drain_type) { case BDRV_DRAIN_ALL: bdrv_drain_all_end(); break; case BDRV_DRAIN: bdrv_drained_end(bs); break; case BDRV_SUBTREE_DRAIN: bdrv_subtree_drained_end(bs); break; default: g_assert_not_reached(); } } static void do_drain_begin_unlocked(enum drain_type drain_type, BlockDriverState *bs) { if (drain_type != BDRV_DRAIN_ALL) { aio_context_acquire(bdrv_get_aio_context(bs)); } do_drain_begin(drain_type, bs); if (drain_type != BDRV_DRAIN_ALL) { aio_context_release(bdrv_get_aio_context(bs)); } } static void do_drain_end_unlocked(enum drain_type drain_type, BlockDriverState *bs) { if (drain_type != BDRV_DRAIN_ALL) { aio_context_acquire(bdrv_get_aio_context(bs)); } do_drain_end(drain_type, bs); if (drain_type != BDRV_DRAIN_ALL) { aio_context_release(bdrv_get_aio_context(bs)); } } static void test_drv_cb_common(enum drain_type drain_type, bool recursive) { BlockBackend *blk; BlockDriverState *bs, *backing; BDRVTestState *s, *backing_s; BlockAIOCB *acb; int aio_ret; QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, &error_abort); s = bs->opaque; blk_insert_bs(blk, bs, &error_abort); backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); backing_s = backing->opaque; bdrv_set_backing_hd(bs, backing, &error_abort); /* Simple bdrv_drain_all_begin/end pair, check that CBs are called */ g_assert_cmpint(s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); do_drain_begin(drain_type, bs); g_assert_cmpint(s->drain_count, ==, 1); g_assert_cmpint(backing_s->drain_count, ==, !!recursive); do_drain_end(drain_type, bs); g_assert_cmpint(s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); /* Now do the same while a request is pending */ aio_ret = -EINPROGRESS; acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); g_assert(acb != NULL); g_assert_cmpint(aio_ret, ==, -EINPROGRESS); g_assert_cmpint(s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); do_drain_begin(drain_type, bs); g_assert_cmpint(aio_ret, ==, 0); g_assert_cmpint(s->drain_count, ==, 1); g_assert_cmpint(backing_s->drain_count, ==, !!recursive); do_drain_end(drain_type, bs); g_assert_cmpint(s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); bdrv_unref(backing); bdrv_unref(bs); blk_unref(blk); } static void test_drv_cb_drain_all(void) { test_drv_cb_common(BDRV_DRAIN_ALL, true); } static void test_drv_cb_drain(void) { test_drv_cb_common(BDRV_DRAIN, false); } static void test_drv_cb_drain_subtree(void) { test_drv_cb_common(BDRV_SUBTREE_DRAIN, true); } static void test_drv_cb_co_drain_all(void) { call_in_coroutine(test_drv_cb_drain_all); } static void test_drv_cb_co_drain(void) { call_in_coroutine(test_drv_cb_drain); } static void test_drv_cb_co_drain_subtree(void) { call_in_coroutine(test_drv_cb_drain_subtree); } static void test_quiesce_common(enum drain_type drain_type, bool recursive) { BlockBackend *blk; BlockDriverState *bs, *backing; blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, &error_abort); blk_insert_bs(blk, bs, &error_abort); backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); bdrv_set_backing_hd(bs, backing, &error_abort); g_assert_cmpint(bs->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); do_drain_begin(drain_type, bs); g_assert_cmpint(bs->quiesce_counter, ==, 1); g_assert_cmpint(backing->quiesce_counter, ==, !!recursive); do_drain_end(drain_type, bs); g_assert_cmpint(bs->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); bdrv_unref(backing); bdrv_unref(bs); blk_unref(blk); } static void test_quiesce_drain_all(void) { test_quiesce_common(BDRV_DRAIN_ALL, true); } static void test_quiesce_drain(void) { test_quiesce_common(BDRV_DRAIN, false); } static void test_quiesce_drain_subtree(void) { test_quiesce_common(BDRV_SUBTREE_DRAIN, true); } static void test_quiesce_co_drain_all(void) { call_in_coroutine(test_quiesce_drain_all); } static void test_quiesce_co_drain(void) { call_in_coroutine(test_quiesce_drain); } static void test_quiesce_co_drain_subtree(void) { call_in_coroutine(test_quiesce_drain_subtree); } static void test_nested(void) { BlockBackend *blk; BlockDriverState *bs, *backing; BDRVTestState *s, *backing_s; enum drain_type outer, inner; blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, &error_abort); s = bs->opaque; blk_insert_bs(blk, bs, &error_abort); backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); backing_s = backing->opaque; bdrv_set_backing_hd(bs, backing, &error_abort); for (outer = 0; outer < DRAIN_TYPE_MAX; outer++) { for (inner = 0; inner < DRAIN_TYPE_MAX; inner++) { int backing_quiesce = (outer != BDRV_DRAIN) + (inner != BDRV_DRAIN); g_assert_cmpint(bs->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); g_assert_cmpint(s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); do_drain_begin(outer, bs); do_drain_begin(inner, bs); g_assert_cmpint(bs->quiesce_counter, ==, 2); g_assert_cmpint(backing->quiesce_counter, ==, backing_quiesce); g_assert_cmpint(s->drain_count, ==, 2); g_assert_cmpint(backing_s->drain_count, ==, backing_quiesce); do_drain_end(inner, bs); do_drain_end(outer, bs); g_assert_cmpint(bs->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); g_assert_cmpint(s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); } } bdrv_unref(backing); bdrv_unref(bs); blk_unref(blk); } static void test_multiparent(void) { BlockBackend *blk_a, *blk_b; BlockDriverState *bs_a, *bs_b, *backing; BDRVTestState *a_s, *b_s, *backing_s; blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR, &error_abort); a_s = bs_a->opaque; blk_insert_bs(blk_a, bs_a, &error_abort); blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR, &error_abort); b_s = bs_b->opaque; blk_insert_bs(blk_b, bs_b, &error_abort); backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); backing_s = backing->opaque; bdrv_set_backing_hd(bs_a, backing, &error_abort); bdrv_set_backing_hd(bs_b, backing, &error_abort); g_assert_cmpint(bs_a->quiesce_counter, ==, 0); g_assert_cmpint(bs_b->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); g_assert_cmpint(a_s->drain_count, ==, 0); g_assert_cmpint(b_s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); g_assert_cmpint(bs_a->quiesce_counter, ==, 1); g_assert_cmpint(bs_b->quiesce_counter, ==, 1); g_assert_cmpint(backing->quiesce_counter, ==, 1); g_assert_cmpint(a_s->drain_count, ==, 1); g_assert_cmpint(b_s->drain_count, ==, 1); g_assert_cmpint(backing_s->drain_count, ==, 1); do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b); g_assert_cmpint(bs_a->quiesce_counter, ==, 2); g_assert_cmpint(bs_b->quiesce_counter, ==, 2); g_assert_cmpint(backing->quiesce_counter, ==, 2); g_assert_cmpint(a_s->drain_count, ==, 2); g_assert_cmpint(b_s->drain_count, ==, 2); g_assert_cmpint(backing_s->drain_count, ==, 2); do_drain_end(BDRV_SUBTREE_DRAIN, bs_b); g_assert_cmpint(bs_a->quiesce_counter, ==, 1); g_assert_cmpint(bs_b->quiesce_counter, ==, 1); g_assert_cmpint(backing->quiesce_counter, ==, 1); g_assert_cmpint(a_s->drain_count, ==, 1); g_assert_cmpint(b_s->drain_count, ==, 1); g_assert_cmpint(backing_s->drain_count, ==, 1); do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); g_assert_cmpint(bs_a->quiesce_counter, ==, 0); g_assert_cmpint(bs_b->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); g_assert_cmpint(a_s->drain_count, ==, 0); g_assert_cmpint(b_s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); bdrv_unref(backing); bdrv_unref(bs_a); bdrv_unref(bs_b); blk_unref(blk_a); blk_unref(blk_b); } static void test_graph_change_drain_subtree(void) { BlockBackend *blk_a, *blk_b; BlockDriverState *bs_a, *bs_b, *backing; BDRVTestState *a_s, *b_s, *backing_s; blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR, &error_abort); a_s = bs_a->opaque; blk_insert_bs(blk_a, bs_a, &error_abort); blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR, &error_abort); b_s = bs_b->opaque; blk_insert_bs(blk_b, bs_b, &error_abort); backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort); backing_s = backing->opaque; bdrv_set_backing_hd(bs_a, backing, &error_abort); g_assert_cmpint(bs_a->quiesce_counter, ==, 0); g_assert_cmpint(bs_b->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); g_assert_cmpint(a_s->drain_count, ==, 0); g_assert_cmpint(b_s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); do_drain_begin(BDRV_SUBTREE_DRAIN, bs_a); do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b); do_drain_begin(BDRV_SUBTREE_DRAIN, bs_b); bdrv_set_backing_hd(bs_b, backing, &error_abort); g_assert_cmpint(bs_a->quiesce_counter, ==, 5); g_assert_cmpint(bs_b->quiesce_counter, ==, 5); g_assert_cmpint(backing->quiesce_counter, ==, 5); g_assert_cmpint(a_s->drain_count, ==, 5); g_assert_cmpint(b_s->drain_count, ==, 5); g_assert_cmpint(backing_s->drain_count, ==, 5); bdrv_set_backing_hd(bs_b, NULL, &error_abort); g_assert_cmpint(bs_a->quiesce_counter, ==, 3); g_assert_cmpint(bs_b->quiesce_counter, ==, 2); g_assert_cmpint(backing->quiesce_counter, ==, 3); g_assert_cmpint(a_s->drain_count, ==, 3); g_assert_cmpint(b_s->drain_count, ==, 2); g_assert_cmpint(backing_s->drain_count, ==, 3); bdrv_set_backing_hd(bs_b, backing, &error_abort); g_assert_cmpint(bs_a->quiesce_counter, ==, 5); g_assert_cmpint(bs_b->quiesce_counter, ==, 5); g_assert_cmpint(backing->quiesce_counter, ==, 5); g_assert_cmpint(a_s->drain_count, ==, 5); g_assert_cmpint(b_s->drain_count, ==, 5); g_assert_cmpint(backing_s->drain_count, ==, 5); do_drain_end(BDRV_SUBTREE_DRAIN, bs_b); do_drain_end(BDRV_SUBTREE_DRAIN, bs_b); do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); do_drain_end(BDRV_SUBTREE_DRAIN, bs_a); g_assert_cmpint(bs_a->quiesce_counter, ==, 0); g_assert_cmpint(bs_b->quiesce_counter, ==, 0); g_assert_cmpint(backing->quiesce_counter, ==, 0); g_assert_cmpint(a_s->drain_count, ==, 0); g_assert_cmpint(b_s->drain_count, ==, 0); g_assert_cmpint(backing_s->drain_count, ==, 0); bdrv_unref(backing); bdrv_unref(bs_a); bdrv_unref(bs_b); blk_unref(blk_a); blk_unref(blk_b); } static void test_graph_change_drain_all(void) { BlockBackend *blk_a, *blk_b; BlockDriverState *bs_a, *bs_b; BDRVTestState *a_s, *b_s; /* Create node A with a BlockBackend */ blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR, &error_abort); a_s = bs_a->opaque; blk_insert_bs(blk_a, bs_a, &error_abort); g_assert_cmpint(bs_a->quiesce_counter, ==, 0); g_assert_cmpint(a_s->drain_count, ==, 0); /* Call bdrv_drain_all_begin() */ bdrv_drain_all_begin(); g_assert_cmpint(bs_a->quiesce_counter, ==, 1); g_assert_cmpint(a_s->drain_count, ==, 1); /* Create node B with a BlockBackend */ blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR, &error_abort); b_s = bs_b->opaque; blk_insert_bs(blk_b, bs_b, &error_abort); g_assert_cmpint(bs_a->quiesce_counter, ==, 1); g_assert_cmpint(bs_b->quiesce_counter, ==, 1); g_assert_cmpint(a_s->drain_count, ==, 1); g_assert_cmpint(b_s->drain_count, ==, 1); /* Unref and finally delete node A */ blk_unref(blk_a); g_assert_cmpint(bs_a->quiesce_counter, ==, 1); g_assert_cmpint(bs_b->quiesce_counter, ==, 1); g_assert_cmpint(a_s->drain_count, ==, 1); g_assert_cmpint(b_s->drain_count, ==, 1); bdrv_unref(bs_a); g_assert_cmpint(bs_b->quiesce_counter, ==, 1); g_assert_cmpint(b_s->drain_count, ==, 1); /* End the drained section */ bdrv_drain_all_end(); g_assert_cmpint(bs_b->quiesce_counter, ==, 0); g_assert_cmpint(b_s->drain_count, ==, 0); bdrv_unref(bs_b); blk_unref(blk_b); } struct test_iothread_data { BlockDriverState *bs; enum drain_type drain_type; int *aio_ret; }; static void test_iothread_drain_entry(void *opaque) { struct test_iothread_data *data = opaque; aio_context_acquire(bdrv_get_aio_context(data->bs)); do_drain_begin(data->drain_type, data->bs); g_assert_cmpint(*data->aio_ret, ==, 0); do_drain_end(data->drain_type, data->bs); aio_context_release(bdrv_get_aio_context(data->bs)); qemu_event_set(&done_event); } static void test_iothread_aio_cb(void *opaque, int ret) { int *aio_ret = opaque; *aio_ret = ret; qemu_event_set(&done_event); } static void test_iothread_main_thread_bh(void *opaque) { struct test_iothread_data *data = opaque; /* Test that the AioContext is not yet locked in a random BH that is * executed during drain, otherwise this would deadlock. */ aio_context_acquire(bdrv_get_aio_context(data->bs)); bdrv_flush(data->bs); aio_context_release(bdrv_get_aio_context(data->bs)); } /* * Starts an AIO request on a BDS that runs in the AioContext of iothread 1. * The request involves a BH on iothread 2 before it can complete. * * @drain_thread = 0 means that do_drain_begin/end are called from the main * thread, @drain_thread = 1 means that they are called from iothread 1. Drain * for this BDS cannot be called from iothread 2 because only the main thread * may do cross-AioContext polling. */ static void test_iothread_common(enum drain_type drain_type, int drain_thread) { BlockBackend *blk; BlockDriverState *bs; BDRVTestState *s; BlockAIOCB *acb; int aio_ret; struct test_iothread_data data; IOThread *a = iothread_new(); IOThread *b = iothread_new(); AioContext *ctx_a = iothread_get_aio_context(a); AioContext *ctx_b = iothread_get_aio_context(b); QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); /* bdrv_drain_all() may only be called from the main loop thread */ if (drain_type == BDRV_DRAIN_ALL && drain_thread != 0) { goto out; } blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, &error_abort); s = bs->opaque; blk_insert_bs(blk, bs, &error_abort); blk_set_aio_context(blk, ctx_a, &error_abort); aio_context_acquire(ctx_a); s->bh_indirection_ctx = ctx_b; aio_ret = -EINPROGRESS; qemu_event_reset(&done_event); if (drain_thread == 0) { acb = blk_aio_preadv(blk, 0, &qiov, 0, test_iothread_aio_cb, &aio_ret); } else { acb = blk_aio_preadv(blk, 0, &qiov, 0, aio_ret_cb, &aio_ret); } g_assert(acb != NULL); g_assert_cmpint(aio_ret, ==, -EINPROGRESS); aio_context_release(ctx_a); data = (struct test_iothread_data) { .bs = bs, .drain_type = drain_type, .aio_ret = &aio_ret, }; switch (drain_thread) { case 0: if (drain_type != BDRV_DRAIN_ALL) { aio_context_acquire(ctx_a); } aio_bh_schedule_oneshot(ctx_a, test_iothread_main_thread_bh, &data); /* The request is running on the IOThread a. Draining its block device * will make sure that it has completed as far as the BDS is concerned, * but the drain in this thread can continue immediately after * bdrv_dec_in_flight() and aio_ret might be assigned only slightly * later. */ do_drain_begin(drain_type, bs); g_assert_cmpint(bs->in_flight, ==, 0); if (drain_type != BDRV_DRAIN_ALL) { aio_context_release(ctx_a); } qemu_event_wait(&done_event); if (drain_type != BDRV_DRAIN_ALL) { aio_context_acquire(ctx_a); } g_assert_cmpint(aio_ret, ==, 0); do_drain_end(drain_type, bs); if (drain_type != BDRV_DRAIN_ALL) { aio_context_release(ctx_a); } break; case 1: aio_bh_schedule_oneshot(ctx_a, test_iothread_drain_entry, &data); qemu_event_wait(&done_event); break; default: g_assert_not_reached(); } aio_context_acquire(ctx_a); blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort); aio_context_release(ctx_a); bdrv_unref(bs); blk_unref(blk); out: iothread_join(a); iothread_join(b); } static void test_iothread_drain_all(void) { test_iothread_common(BDRV_DRAIN_ALL, 0); test_iothread_common(BDRV_DRAIN_ALL, 1); } static void test_iothread_drain(void) { test_iothread_common(BDRV_DRAIN, 0); test_iothread_common(BDRV_DRAIN, 1); } static void test_iothread_drain_subtree(void) { test_iothread_common(BDRV_SUBTREE_DRAIN, 0); test_iothread_common(BDRV_SUBTREE_DRAIN, 1); } typedef struct TestBlockJob { BlockJob common; int run_ret; int prepare_ret; bool running; bool should_complete; } TestBlockJob; static int test_job_prepare(Job *job) { TestBlockJob *s = container_of(job, TestBlockJob, common.job); /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ blk_flush(s->common.blk); return s->prepare_ret; } static void test_job_commit(Job *job) { TestBlockJob *s = container_of(job, TestBlockJob, common.job); /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ blk_flush(s->common.blk); } static void test_job_abort(Job *job) { TestBlockJob *s = container_of(job, TestBlockJob, common.job); /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */ blk_flush(s->common.blk); } static int coroutine_fn test_job_run(Job *job, Error **errp) { TestBlockJob *s = container_of(job, TestBlockJob, common.job); /* We are running the actual job code past the pause point in * job_co_entry(). */ s->running = true; job_transition_to_ready(&s->common.job); while (!s->should_complete) { /* Avoid job_sleep_ns() because it marks the job as !busy. We want to * emulate some actual activity (probably some I/O) here so that drain * has to wait for this activity to stop. */ qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); job_pause_point(&s->common.job); } return s->run_ret; } static void test_job_complete(Job *job, Error **errp) { TestBlockJob *s = container_of(job, TestBlockJob, common.job); s->should_complete = true; } BlockJobDriver test_job_driver = { .job_driver = { .instance_size = sizeof(TestBlockJob), .free = block_job_free, .user_resume = block_job_user_resume, .drain = block_job_drain, .run = test_job_run, .complete = test_job_complete, .prepare = test_job_prepare, .commit = test_job_commit, .abort = test_job_abort, }, }; enum test_job_result { TEST_JOB_SUCCESS, TEST_JOB_FAIL_RUN, TEST_JOB_FAIL_PREPARE, }; enum test_job_drain_node { TEST_JOB_DRAIN_SRC, TEST_JOB_DRAIN_SRC_CHILD, TEST_JOB_DRAIN_SRC_PARENT, }; static void test_blockjob_common_drain_node(enum drain_type drain_type, bool use_iothread, enum test_job_result result, enum test_job_drain_node drain_node) { BlockBackend *blk_src, *blk_target; BlockDriverState *src, *src_backing, *src_overlay, *target, *drain_bs; BlockJob *job; TestBlockJob *tjob; IOThread *iothread = NULL; AioContext *ctx; int ret; src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR, &error_abort); src_backing = bdrv_new_open_driver(&bdrv_test, "source-backing", BDRV_O_RDWR, &error_abort); src_overlay = bdrv_new_open_driver(&bdrv_test, "source-overlay", BDRV_O_RDWR, &error_abort); bdrv_set_backing_hd(src_overlay, src, &error_abort); bdrv_unref(src); bdrv_set_backing_hd(src, src_backing, &error_abort); bdrv_unref(src_backing); blk_src = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); blk_insert_bs(blk_src, src_overlay, &error_abort); switch (drain_node) { case TEST_JOB_DRAIN_SRC: drain_bs = src; break; case TEST_JOB_DRAIN_SRC_CHILD: drain_bs = src_backing; break; case TEST_JOB_DRAIN_SRC_PARENT: drain_bs = src_overlay; break; default: g_assert_not_reached(); } if (use_iothread) { iothread = iothread_new(); ctx = iothread_get_aio_context(iothread); blk_set_aio_context(blk_src, ctx, &error_abort); } else { ctx = qemu_get_aio_context(); } target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR, &error_abort); blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); blk_insert_bs(blk_target, target, &error_abort); blk_set_allow_aio_context_change(blk_target, true); aio_context_acquire(ctx); tjob = block_job_create("job0", &test_job_driver, NULL, src, 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort); job = &tjob->common; block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort); switch (result) { case TEST_JOB_SUCCESS: break; case TEST_JOB_FAIL_RUN: tjob->run_ret = -EIO; break; case TEST_JOB_FAIL_PREPARE: tjob->prepare_ret = -EIO; break; } job_start(&job->job); aio_context_release(ctx); if (use_iothread) { /* job_co_entry() is run in the I/O thread, wait for the actual job * code to start (we don't want to catch the job in the pause point in * job_co_entry(). */ while (!tjob->running) { aio_poll(qemu_get_aio_context(), false); } } g_assert_cmpint(job->job.pause_count, ==, 0); g_assert_false(job->job.paused); g_assert_true(tjob->running); g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ do_drain_begin_unlocked(drain_type, drain_bs); if (drain_type == BDRV_DRAIN_ALL) { /* bdrv_drain_all() drains both src and target */ g_assert_cmpint(job->job.pause_count, ==, 2); } else { g_assert_cmpint(job->job.pause_count, ==, 1); } g_assert_true(job->job.paused); g_assert_false(job->job.busy); /* The job is paused */ do_drain_end_unlocked(drain_type, drain_bs); if (use_iothread) { /* paused is reset in the I/O thread, wait for it */ while (job->job.paused) { aio_poll(qemu_get_aio_context(), false); } } g_assert_cmpint(job->job.pause_count, ==, 0); g_assert_false(job->job.paused); g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ do_drain_begin_unlocked(drain_type, target); if (drain_type == BDRV_DRAIN_ALL) { /* bdrv_drain_all() drains both src and target */ g_assert_cmpint(job->job.pause_count, ==, 2); } else { g_assert_cmpint(job->job.pause_count, ==, 1); } g_assert_true(job->job.paused); g_assert_false(job->job.busy); /* The job is paused */ do_drain_end_unlocked(drain_type, target); if (use_iothread) { /* paused is reset in the I/O thread, wait for it */ while (job->job.paused) { aio_poll(qemu_get_aio_context(), false); } } g_assert_cmpint(job->job.pause_count, ==, 0); g_assert_false(job->job.paused); g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */ aio_context_acquire(ctx); ret = job_complete_sync(&job->job, &error_abort); g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO)); if (use_iothread) { blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort); assert(blk_get_aio_context(blk_target) == qemu_get_aio_context()); } aio_context_release(ctx); blk_unref(blk_src); blk_unref(blk_target); bdrv_unref(src_overlay); bdrv_unref(target); if (iothread) { iothread_join(iothread); } } static void test_blockjob_common(enum drain_type drain_type, bool use_iothread, enum test_job_result result) { test_blockjob_common_drain_node(drain_type, use_iothread, result, TEST_JOB_DRAIN_SRC); test_blockjob_common_drain_node(drain_type, use_iothread, result, TEST_JOB_DRAIN_SRC_CHILD); if (drain_type == BDRV_SUBTREE_DRAIN) { test_blockjob_common_drain_node(drain_type, use_iothread, result, TEST_JOB_DRAIN_SRC_PARENT); } } static void test_blockjob_drain_all(void) { test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS); } static void test_blockjob_drain(void) { test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_SUCCESS); } static void test_blockjob_drain_subtree(void) { test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_SUCCESS); } static void test_blockjob_error_drain_all(void) { test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_RUN); test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_PREPARE); } static void test_blockjob_error_drain(void) { test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_RUN); test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_PREPARE); } static void test_blockjob_error_drain_subtree(void) { test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_RUN); test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_PREPARE); } static void test_blockjob_iothread_drain_all(void) { test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_SUCCESS); } static void test_blockjob_iothread_drain(void) { test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_SUCCESS); } static void test_blockjob_iothread_drain_subtree(void) { test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_SUCCESS); } static void test_blockjob_iothread_error_drain_all(void) { test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_RUN); test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_PREPARE); } static void test_blockjob_iothread_error_drain(void) { test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_RUN); test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_PREPARE); } static void test_blockjob_iothread_error_drain_subtree(void) { test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_RUN); test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_PREPARE); } typedef struct BDRVTestTopState { BdrvChild *wait_child; } BDRVTestTopState; static void bdrv_test_top_close(BlockDriverState *bs) { BdrvChild *c, *next_c; QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { bdrv_unref_child(bs, c); } } static int coroutine_fn bdrv_test_top_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { BDRVTestTopState *tts = bs->opaque; return bdrv_co_preadv(tts->wait_child, offset, bytes, qiov, flags); } static BlockDriver bdrv_test_top_driver = { .format_name = "test_top_driver", .instance_size = sizeof(BDRVTestTopState), .bdrv_close = bdrv_test_top_close, .bdrv_co_preadv = bdrv_test_top_co_preadv, .bdrv_child_perm = bdrv_format_default_perms, }; typedef struct TestCoDeleteByDrainData { BlockBackend *blk; bool detach_instead_of_delete; bool done; } TestCoDeleteByDrainData; static void coroutine_fn test_co_delete_by_drain(void *opaque) { TestCoDeleteByDrainData *dbdd = opaque; BlockBackend *blk = dbdd->blk; BlockDriverState *bs = blk_bs(blk); BDRVTestTopState *tts = bs->opaque; void *buffer = g_malloc(65536); QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buffer, 65536); /* Pretend some internal write operation from parent to child. * Important: We have to read from the child, not from the parent! * Draining works by first propagating it all up the tree to the * root and then waiting for drainage from root to the leaves * (protocol nodes). If we have a request waiting on the root, * everything will be drained before we go back down the tree, but * we do not want that. We want to be in the middle of draining * when this following requests returns. */ bdrv_co_preadv(tts->wait_child, 0, 65536, &qiov, 0); g_assert_cmpint(bs->refcnt, ==, 1); if (!dbdd->detach_instead_of_delete) { blk_unref(blk); } else { BdrvChild *c, *next_c; QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { bdrv_unref_child(bs, c); } } dbdd->done = true; g_free(buffer); } /** * Test what happens when some BDS has some children, you drain one of * them and this results in the BDS being deleted. * * If @detach_instead_of_delete is set, the BDS is not going to be * deleted but will only detach all of its children. */ static void do_test_delete_by_drain(bool detach_instead_of_delete, enum drain_type drain_type) { BlockBackend *blk; BlockDriverState *bs, *child_bs, *null_bs; BDRVTestTopState *tts; TestCoDeleteByDrainData dbdd; Coroutine *co; bs = bdrv_new_open_driver(&bdrv_test_top_driver, "top", BDRV_O_RDWR, &error_abort); bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; tts = bs->opaque; null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, &error_abort); bdrv_attach_child(bs, null_bs, "null-child", &child_file, &error_abort); /* This child will be the one to pass to requests through to, and * it will stall until a drain occurs */ child_bs = bdrv_new_open_driver(&bdrv_test, "child", BDRV_O_RDWR, &error_abort); child_bs->total_sectors = 65536 >> BDRV_SECTOR_BITS; /* Takes our reference to child_bs */ tts->wait_child = bdrv_attach_child(bs, child_bs, "wait-child", &child_file, &error_abort); /* This child is just there to be deleted * (for detach_instead_of_delete == true) */ null_bs = bdrv_open("null-co://", NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, &error_abort); bdrv_attach_child(bs, null_bs, "null-child", &child_file, &error_abort); blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); blk_insert_bs(blk, bs, &error_abort); /* Referenced by blk now */ bdrv_unref(bs); g_assert_cmpint(bs->refcnt, ==, 1); g_assert_cmpint(child_bs->refcnt, ==, 1); g_assert_cmpint(null_bs->refcnt, ==, 1); dbdd = (TestCoDeleteByDrainData){ .blk = blk, .detach_instead_of_delete = detach_instead_of_delete, .done = false, }; co = qemu_coroutine_create(test_co_delete_by_drain, &dbdd); qemu_coroutine_enter(co); /* Drain the child while the read operation is still pending. * This should result in the operation finishing and * test_co_delete_by_drain() resuming. Thus, @bs will be deleted * and the coroutine will exit while this drain operation is still * in progress. */ switch (drain_type) { case BDRV_DRAIN: bdrv_ref(child_bs); bdrv_drain(child_bs); bdrv_unref(child_bs); break; case BDRV_SUBTREE_DRAIN: /* Would have to ref/unref bs here for !detach_instead_of_delete, but * then the whole test becomes pointless because the graph changes * don't occur during the drain any more. */ assert(detach_instead_of_delete); bdrv_subtree_drained_begin(bs); bdrv_subtree_drained_end(bs); break; case BDRV_DRAIN_ALL: bdrv_drain_all_begin(); bdrv_drain_all_end(); break; default: g_assert_not_reached(); } while (!dbdd.done) { aio_poll(qemu_get_aio_context(), true); } if (detach_instead_of_delete) { /* Here, the reference has not passed over to the coroutine, * so we have to delete the BB ourselves */ blk_unref(blk); } } static void test_delete_by_drain(void) { do_test_delete_by_drain(false, BDRV_DRAIN); } static void test_detach_by_drain_all(void) { do_test_delete_by_drain(true, BDRV_DRAIN_ALL); } static void test_detach_by_drain(void) { do_test_delete_by_drain(true, BDRV_DRAIN); } static void test_detach_by_drain_subtree(void) { do_test_delete_by_drain(true, BDRV_SUBTREE_DRAIN); } struct detach_by_parent_data { BlockDriverState *parent_b; BdrvChild *child_b; BlockDriverState *c; BdrvChild *child_c; bool by_parent_cb; }; static struct detach_by_parent_data detach_by_parent_data; static void detach_indirect_bh(void *opaque) { struct detach_by_parent_data *data = opaque; bdrv_unref_child(data->parent_b, data->child_b); bdrv_ref(data->c); data->child_c = bdrv_attach_child(data->parent_b, data->c, "PB-C", &child_file, &error_abort); } static void detach_by_parent_aio_cb(void *opaque, int ret) { struct detach_by_parent_data *data = &detach_by_parent_data; g_assert_cmpint(ret, ==, 0); if (data->by_parent_cb) { detach_indirect_bh(data); } } static void detach_by_driver_cb_drained_begin(BdrvChild *child) { aio_bh_schedule_oneshot(qemu_get_current_aio_context(), detach_indirect_bh, &detach_by_parent_data); child_file.drained_begin(child); } static BdrvChildRole detach_by_driver_cb_role; /* * Initial graph: * * PA PB * \ / \ * A B C * * by_parent_cb == true: Test that parent callbacks don't poll * * PA has a pending write request whose callback changes the child nodes of * PB: It removes B and adds C instead. The subtree of PB is drained, which * will indirectly drain the write request, too. * * by_parent_cb == false: Test that bdrv_drain_invoke() doesn't poll * * PA's BdrvChildRole has a .drained_begin callback that schedules a BH * that does the same graph change. If bdrv_drain_invoke() calls it, the * state is messed up, but if it is only polled in the single * BDRV_POLL_WHILE() at the end of the drain, this should work fine. */ static void test_detach_indirect(bool by_parent_cb) { BlockBackend *blk; BlockDriverState *parent_a, *parent_b, *a, *b, *c; BdrvChild *child_a, *child_b; BlockAIOCB *acb; QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0); if (!by_parent_cb) { detach_by_driver_cb_role = child_file; detach_by_driver_cb_role.drained_begin = detach_by_driver_cb_drained_begin; } /* Create all involved nodes */ parent_a = bdrv_new_open_driver(&bdrv_test, "parent-a", BDRV_O_RDWR, &error_abort); parent_b = bdrv_new_open_driver(&bdrv_test, "parent-b", 0, &error_abort); a = bdrv_new_open_driver(&bdrv_test, "a", BDRV_O_RDWR, &error_abort); b = bdrv_new_open_driver(&bdrv_test, "b", BDRV_O_RDWR, &error_abort); c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort); /* blk is a BB for parent-a */ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); blk_insert_bs(blk, parent_a, &error_abort); bdrv_unref(parent_a); /* If we want to get bdrv_drain_invoke() to call aio_poll(), the driver * callback must not return immediately. */ if (!by_parent_cb) { BDRVTestState *s = parent_a->opaque; s->sleep_in_drain_begin = true; } /* Set child relationships */ bdrv_ref(b); bdrv_ref(a); child_b = bdrv_attach_child(parent_b, b, "PB-B", &child_file, &error_abort); child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_backing, &error_abort); bdrv_ref(a); bdrv_attach_child(parent_a, a, "PA-A", by_parent_cb ? &child_file : &detach_by_driver_cb_role, &error_abort); g_assert_cmpint(parent_a->refcnt, ==, 1); g_assert_cmpint(parent_b->refcnt, ==, 1); g_assert_cmpint(a->refcnt, ==, 3); g_assert_cmpint(b->refcnt, ==, 2); g_assert_cmpint(c->refcnt, ==, 1); g_assert(QLIST_FIRST(&parent_b->children) == child_a); g_assert(QLIST_NEXT(child_a, next) == child_b); g_assert(QLIST_NEXT(child_b, next) == NULL); /* Start the evil write request */ detach_by_parent_data = (struct detach_by_parent_data) { .parent_b = parent_b, .child_b = child_b, .c = c, .by_parent_cb = by_parent_cb, }; acb = blk_aio_preadv(blk, 0, &qiov, 0, detach_by_parent_aio_cb, NULL); g_assert(acb != NULL); /* Drain and check the expected result */ bdrv_subtree_drained_begin(parent_b); g_assert(detach_by_parent_data.child_c != NULL); g_assert_cmpint(parent_a->refcnt, ==, 1); g_assert_cmpint(parent_b->refcnt, ==, 1); g_assert_cmpint(a->refcnt, ==, 3); g_assert_cmpint(b->refcnt, ==, 1); g_assert_cmpint(c->refcnt, ==, 2); g_assert(QLIST_FIRST(&parent_b->children) == detach_by_parent_data.child_c); g_assert(QLIST_NEXT(detach_by_parent_data.child_c, next) == child_a); g_assert(QLIST_NEXT(child_a, next) == NULL); g_assert_cmpint(parent_a->quiesce_counter, ==, 1); g_assert_cmpint(parent_b->quiesce_counter, ==, 1); g_assert_cmpint(a->quiesce_counter, ==, 1); g_assert_cmpint(b->quiesce_counter, ==, 0); g_assert_cmpint(c->quiesce_counter, ==, 1); bdrv_subtree_drained_end(parent_b); bdrv_unref(parent_b); blk_unref(blk); g_assert_cmpint(a->refcnt, ==, 1); g_assert_cmpint(b->refcnt, ==, 1); g_assert_cmpint(c->refcnt, ==, 1); bdrv_unref(a); bdrv_unref(b); bdrv_unref(c); } static void test_detach_by_parent_cb(void) { test_detach_indirect(true); } static void test_detach_by_driver_cb(void) { test_detach_indirect(false); } static void test_append_to_drained(void) { BlockBackend *blk; BlockDriverState *base, *overlay; BDRVTestState *base_s, *overlay_s; blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL); base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort); base_s = base->opaque; blk_insert_bs(blk, base, &error_abort); overlay = bdrv_new_open_driver(&bdrv_test, "overlay", BDRV_O_RDWR, &error_abort); overlay_s = overlay->opaque; do_drain_begin(BDRV_DRAIN, base); g_assert_cmpint(base->quiesce_counter, ==, 1); g_assert_cmpint(base_s->drain_count, ==, 1); g_assert_cmpint(base->in_flight, ==, 0); /* Takes ownership of overlay, so we don't have to unref it later */ bdrv_append(overlay, base, &error_abort); g_assert_cmpint(base->in_flight, ==, 0); g_assert_cmpint(overlay->in_flight, ==, 0); g_assert_cmpint(base->quiesce_counter, ==, 1); g_assert_cmpint(base_s->drain_count, ==, 1); g_assert_cmpint(overlay->quiesce_counter, ==, 1); g_assert_cmpint(overlay_s->drain_count, ==, 1); do_drain_end(BDRV_DRAIN, base); g_assert_cmpint(base->quiesce_counter, ==, 0); g_assert_cmpint(base_s->drain_count, ==, 0); g_assert_cmpint(overlay->quiesce_counter, ==, 0); g_assert_cmpint(overlay_s->drain_count, ==, 0); bdrv_unref(base); blk_unref(blk); } static void test_set_aio_context(void) { BlockDriverState *bs; IOThread *a = iothread_new(); IOThread *b = iothread_new(); AioContext *ctx_a = iothread_get_aio_context(a); AioContext *ctx_b = iothread_get_aio_context(b); bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR, &error_abort); bdrv_drained_begin(bs); bdrv_try_set_aio_context(bs, ctx_a, &error_abort); aio_context_acquire(ctx_a); bdrv_drained_end(bs); bdrv_drained_begin(bs); bdrv_try_set_aio_context(bs, ctx_b, &error_abort); aio_context_release(ctx_a); aio_context_acquire(ctx_b); bdrv_try_set_aio_context(bs, qemu_get_aio_context(), &error_abort); aio_context_release(ctx_b); bdrv_drained_end(bs); bdrv_unref(bs); iothread_join(a); iothread_join(b); } typedef struct TestDropBackingBlockJob { BlockJob common; bool should_complete; bool *did_complete; BlockDriverState *detach_also; } TestDropBackingBlockJob; static int coroutine_fn test_drop_backing_job_run(Job *job, Error **errp) { TestDropBackingBlockJob *s = container_of(job, TestDropBackingBlockJob, common.job); while (!s->should_complete) { job_sleep_ns(job, 0); } return 0; } static void test_drop_backing_job_commit(Job *job) { TestDropBackingBlockJob *s = container_of(job, TestDropBackingBlockJob, common.job); bdrv_set_backing_hd(blk_bs(s->common.blk), NULL, &error_abort); bdrv_set_backing_hd(s->detach_also, NULL, &error_abort); *s->did_complete = true; } static const BlockJobDriver test_drop_backing_job_driver = { .job_driver = { .instance_size = sizeof(TestDropBackingBlockJob), .free = block_job_free, .user_resume = block_job_user_resume, .drain = block_job_drain, .run = test_drop_backing_job_run, .commit = test_drop_backing_job_commit, } }; /** * Creates a child node with three parent nodes on it, and then runs a * block job on the final one, parent-node-2. * * The job is then asked to complete before a section where the child * is drained. * * Ending this section will undrain the child's parents, first * parent-node-2, then parent-node-1, then parent-node-0 -- the parent * list is in reverse order of how they were added. Ending the drain * on parent-node-2 will resume the job, thus completing it and * scheduling job_exit(). * * Ending the drain on parent-node-1 will poll the AioContext, which * lets job_exit() and thus test_drop_backing_job_commit() run. That * function first removes the child as parent-node-2's backing file. * * In old (and buggy) implementations, there are two problems with * that: * (A) bdrv_drain_invoke() polls for every node that leaves the * drained section. This means that job_exit() is scheduled * before the child has left the drained section. Its * quiesce_counter is therefore still 1 when it is removed from * parent-node-2. * * (B) bdrv_replace_child_noperm() calls drained_end() on the old * child's parents as many times as the child is quiesced. This * means it will call drained_end() on parent-node-2 once. * Because parent-node-2 is no longer quiesced at this point, this * will fail. * * bdrv_replace_child_noperm() therefore must call drained_end() on * the parent only if it really is still drained because the child is * drained. * * If removing child from parent-node-2 was successful (as it should * be), test_drop_backing_job_commit() will then also remove the child * from parent-node-0. * * With an old version of our drain infrastructure ((A) above), that * resulted in the following flow: * * 1. child attempts to leave its drained section. The call recurses * to its parents. * * 2. parent-node-2 leaves the drained section. Polling in * bdrv_drain_invoke() will schedule job_exit(). * * 3. parent-node-1 leaves the drained section. Polling in * bdrv_drain_invoke() will run job_exit(), thus disconnecting * parent-node-0 from the child node. * * 4. bdrv_parent_drained_end() uses a QLIST_FOREACH_SAFE() loop to * iterate over the parents. Thus, it now accesses the BdrvChild * object that used to connect parent-node-0 and the child node. * However, that object no longer exists, so it accesses a dangling * pointer. * * The solution is to only poll once when running a bdrv_drained_end() * operation, specifically at the end when all drained_end() * operations for all involved nodes have been scheduled. * Note that this also solves (A) above, thus hiding (B). */ static void test_blockjob_commit_by_drained_end(void) { BlockDriverState *bs_child, *bs_parents[3]; TestDropBackingBlockJob *job; bool job_has_completed = false; int i; bs_child = bdrv_new_open_driver(&bdrv_test, "child-node", BDRV_O_RDWR, &error_abort); for (i = 0; i < 3; i++) { char name[32]; snprintf(name, sizeof(name), "parent-node-%i", i); bs_parents[i] = bdrv_new_open_driver(&bdrv_test, name, BDRV_O_RDWR, &error_abort); bdrv_set_backing_hd(bs_parents[i], bs_child, &error_abort); } job = block_job_create("job", &test_drop_backing_job_driver, NULL, bs_parents[2], 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort); job->detach_also = bs_parents[0]; job->did_complete = &job_has_completed; job_start(&job->common.job); job->should_complete = true; bdrv_drained_begin(bs_child); g_assert(!job_has_completed); bdrv_drained_end(bs_child); g_assert(job_has_completed); bdrv_unref(bs_parents[0]); bdrv_unref(bs_parents[1]); bdrv_unref(bs_parents[2]); bdrv_unref(bs_child); } int main(int argc, char **argv) { int ret; bdrv_init(); qemu_init_main_loop(&error_abort); g_test_init(&argc, &argv, NULL); qemu_event_init(&done_event, false); g_test_add_func("/bdrv-drain/driver-cb/drain_all", test_drv_cb_drain_all); g_test_add_func("/bdrv-drain/driver-cb/drain", test_drv_cb_drain); g_test_add_func("/bdrv-drain/driver-cb/drain_subtree", test_drv_cb_drain_subtree); g_test_add_func("/bdrv-drain/driver-cb/co/drain_all", test_drv_cb_co_drain_all); g_test_add_func("/bdrv-drain/driver-cb/co/drain", test_drv_cb_co_drain); g_test_add_func("/bdrv-drain/driver-cb/co/drain_subtree", test_drv_cb_co_drain_subtree); g_test_add_func("/bdrv-drain/quiesce/drain_all", test_quiesce_drain_all); g_test_add_func("/bdrv-drain/quiesce/drain", test_quiesce_drain); g_test_add_func("/bdrv-drain/quiesce/drain_subtree", test_quiesce_drain_subtree); g_test_add_func("/bdrv-drain/quiesce/co/drain_all", test_quiesce_co_drain_all); g_test_add_func("/bdrv-drain/quiesce/co/drain", test_quiesce_co_drain); g_test_add_func("/bdrv-drain/quiesce/co/drain_subtree", test_quiesce_co_drain_subtree); g_test_add_func("/bdrv-drain/nested", test_nested); g_test_add_func("/bdrv-drain/multiparent", test_multiparent); g_test_add_func("/bdrv-drain/graph-change/drain_subtree", test_graph_change_drain_subtree); g_test_add_func("/bdrv-drain/graph-change/drain_all", test_graph_change_drain_all); g_test_add_func("/bdrv-drain/iothread/drain_all", test_iothread_drain_all); g_test_add_func("/bdrv-drain/iothread/drain", test_iothread_drain); g_test_add_func("/bdrv-drain/iothread/drain_subtree", test_iothread_drain_subtree); g_test_add_func("/bdrv-drain/blockjob/drain_all", test_blockjob_drain_all); g_test_add_func("/bdrv-drain/blockjob/drain", test_blockjob_drain); g_test_add_func("/bdrv-drain/blockjob/drain_subtree", test_blockjob_drain_subtree); g_test_add_func("/bdrv-drain/blockjob/error/drain_all", test_blockjob_error_drain_all); g_test_add_func("/bdrv-drain/blockjob/error/drain", test_blockjob_error_drain); g_test_add_func("/bdrv-drain/blockjob/error/drain_subtree", test_blockjob_error_drain_subtree); g_test_add_func("/bdrv-drain/blockjob/iothread/drain_all", test_blockjob_iothread_drain_all); g_test_add_func("/bdrv-drain/blockjob/iothread/drain", test_blockjob_iothread_drain); g_test_add_func("/bdrv-drain/blockjob/iothread/drain_subtree", test_blockjob_iothread_drain_subtree); g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_all", test_blockjob_iothread_error_drain_all); g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain", test_blockjob_iothread_error_drain); g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_subtree", test_blockjob_iothread_error_drain_subtree); g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain); g_test_add_func("/bdrv-drain/detach/drain_all", test_detach_by_drain_all); g_test_add_func("/bdrv-drain/detach/drain", test_detach_by_drain); g_test_add_func("/bdrv-drain/detach/drain_subtree", test_detach_by_drain_subtree); g_test_add_func("/bdrv-drain/detach/parent_cb", test_detach_by_parent_cb); g_test_add_func("/bdrv-drain/detach/driver_cb", test_detach_by_driver_cb); g_test_add_func("/bdrv-drain/attach/drain", test_append_to_drained); g_test_add_func("/bdrv-drain/set_aio_context", test_set_aio_context); g_test_add_func("/bdrv-drain/blockjob/commit_by_drained_end", test_blockjob_commit_by_drained_end); ret = g_test_run(); qemu_event_destroy(&done_event); return ret; }