test-bdrv-drain: Graph change through parent callback

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2018-03-23 18:48:39 +01:00
parent dcf94a23b1
commit 231281ab42

View File

@ -982,6 +982,135 @@ 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;
@ -1032,6 +1161,7 @@ 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);