From 58476c0b2e67824bd2108055a315f8b9ebc54e31 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 10 Oct 2018 20:21:42 +0100 Subject: [PATCH 16/49] test-bdrv-drain: Graph change through parent callback RH-Author: Kevin Wolf Message-id: <20181010202213.7372-4-kwolf@redhat.com> Patchwork-id: 82595 O-Subject: [RHEL-8 qemu-kvm PATCH 13/44] test-bdrv-drain: Graph change through parent callback Bugzilla: 1637976 RH-Acked-by: Max Reitz RH-Acked-by: John Snow RH-Acked-by: Thomas Huth Signed-off-by: Kevin Wolf (cherry picked from commit 231281ab42dad2b407b941e36ad11cbc6586e937) Signed-off-by: Kevin Wolf Signed-off-by: Danilo C. L. de Paula --- tests/test-bdrv-drain.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c index 38706b0..f786326 100644 --- a/tests/test-bdrv-drain.c +++ b/tests/test-bdrv-drain.c @@ -977,6 +977,135 @@ static void test_detach_by_drain_subtree(void) } +struct detach_by_parent_data { + BlockDriverState *parent_b; + BdrvChild *child_b; + BlockDriverState *c; + BdrvChild *child_c; +}; + +static void detach_by_parent_aio_cb(void *opaque, int ret) +{ + struct detach_by_parent_data *data = opaque; + + g_assert_cmpint(ret, ==, 0); + 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); +} + +/* + * Initial graph: + * + * PA PB + * \ / \ + * A B C + * + * 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. + */ +static void test_detach_by_parent_cb(void) +{ + BlockBackend *blk; + BlockDriverState *parent_a, *parent_b, *a, *b, *c; + BdrvChild *child_a, *child_b; + BlockAIOCB *acb; + struct detach_by_parent_data data; + + QEMUIOVector qiov; + struct iovec iov = { + .iov_base = NULL, + .iov_len = 0, + }; + qemu_iovec_init_external(&qiov, &iov, 1); + + /* 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(BLK_PERM_ALL, BLK_PERM_ALL); + blk_insert_bs(blk, parent_a, &error_abort); + bdrv_unref(parent_a); + + /* 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", &child_file, &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 */ + data = (struct detach_by_parent_data) { + .parent_b = parent_b, + .child_b = child_b, + .c = c, + }; + acb = blk_aio_preadv(blk, 0, &qiov, 0, detach_by_parent_aio_cb, &data); + g_assert(acb != NULL); + + /* Drain and check the expected result */ + bdrv_subtree_drained_begin(parent_b); + + g_assert(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) == data.child_c); + g_assert(QLIST_NEXT(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); + + /* XXX Once bdrv_close() unref's children instead of just detaching them, + * this won't be necessary any more. */ + bdrv_unref(a); + bdrv_unref(a); + bdrv_unref(c); + + 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); +} + + int main(int argc, char **argv) { int ret; @@ -1027,6 +1156,7 @@ int main(int argc, char **argv) g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain); 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); ret = g_test_run(); qemu_event_destroy(&done_event); -- 1.8.3.1