test-bdrv-drain: Don't modify the graph in coroutines

test-bdrv-drain contains a few test cases that are run both in coroutine
and non-coroutine context. Running the entire code including the setup
and shutdown in coroutines is incorrect because graph modifications can
generally not happen in coroutines.

Change the test so that creating and destroying the test nodes and
BlockBackends always happens outside of coroutine context.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20230504115750.54437-6-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 75 insertions, 37 deletions

diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c
index d9d3807..9a4c5e5 100644
--- a/tests/unit/test-bdrv-drain.c
+++ b/tests/unit/test-bdrv-drain.c
@@ -188,6 +188,25 @@ static void do_drain_begin_unlocked(enum drain_type drain_type, BlockDriverState
     }
 }
 
+static BlockBackend * no_coroutine_fn test_setup(void)
+{
+    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);
+
+    bdrv_unref(backing);
+    bdrv_unref(bs);
+
+    return blk;
+}
+
 static void do_drain_end_unlocked(enum drain_type drain_type, BlockDriverState *bs)
 {
     if (drain_type != BDRV_DRAIN_ALL) {
@@ -199,25 +218,19 @@ static void do_drain_end_unlocked(enum drain_type drain_type, BlockDriverState *
     }
 }
 
-static void test_drv_cb_common(enum drain_type drain_type, bool recursive)
+static void test_drv_cb_common(BlockBackend *blk, enum drain_type drain_type,
+                               bool recursive)
 {
-    BlockBackend *blk;
-    BlockDriverState *bs, *backing;
+    BlockDriverState *bs = blk_bs(blk);
+    BlockDriverState *backing = bs->backing->bs;
     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);
@@ -252,44 +265,53 @@ static void test_drv_cb_common(enum drain_type drain_type, bool recursive)
 
     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);
+    BlockBackend *blk = test_setup();
+    test_drv_cb_common(blk, BDRV_DRAIN_ALL, true);
+    blk_unref(blk);
 }
 
 static void test_drv_cb_drain(void)
 {
-    test_drv_cb_common(BDRV_DRAIN, false);
+    BlockBackend *blk = test_setup();
+    test_drv_cb_common(blk, BDRV_DRAIN, false);
+    blk_unref(blk);
+}
+
+static void coroutine_fn test_drv_cb_co_drain_all_entry(void)
+{
+    BlockBackend *blk = blk_all_next(NULL);
+    test_drv_cb_common(blk, BDRV_DRAIN_ALL, true);
 }
 
 static void test_drv_cb_co_drain_all(void)
 {
-    call_in_coroutine(test_drv_cb_drain_all);
+    BlockBackend *blk = test_setup();
+    call_in_coroutine(test_drv_cb_co_drain_all_entry);
+    blk_unref(blk);
 }
 
-static void test_drv_cb_co_drain(void)
+static void coroutine_fn test_drv_cb_co_drain_entry(void)
 {
-    call_in_coroutine(test_drv_cb_drain);
+    BlockBackend *blk = blk_all_next(NULL);
+    test_drv_cb_common(blk, BDRV_DRAIN, false);
 }
 
-static void test_quiesce_common(enum drain_type drain_type, bool recursive)
+static void test_drv_cb_co_drain(void)
 {
-    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);
+    BlockBackend *blk = test_setup();
+    call_in_coroutine(test_drv_cb_co_drain_entry);
+    blk_unref(blk);
+}
 
-    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0, &error_abort);
-    bdrv_set_backing_hd(bs, backing, &error_abort);
+static void test_quiesce_common(BlockBackend *blk, enum drain_type drain_type,
+                                bool recursive)
+{
+    BlockDriverState *bs = blk_bs(blk);
+    BlockDriverState *backing = bs->backing->bs;
 
     g_assert_cmpint(bs->quiesce_counter, ==, 0);
     g_assert_cmpint(backing->quiesce_counter, ==, 0);
@@ -307,30 +329,46 @@ static void test_quiesce_common(enum drain_type drain_type, bool recursive)
 
     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);
+    BlockBackend *blk = test_setup();
+    test_quiesce_common(blk, BDRV_DRAIN_ALL, true);
+    blk_unref(blk);
 }
 
 static void test_quiesce_drain(void)
 {
-    test_quiesce_common(BDRV_DRAIN, false);
+    BlockBackend *blk = test_setup();
+    test_quiesce_common(blk, BDRV_DRAIN, false);
+    blk_unref(blk);
+}
+
+static void coroutine_fn test_quiesce_co_drain_all_entry(void)
+{
+    BlockBackend *blk = blk_all_next(NULL);
+    test_quiesce_common(blk, BDRV_DRAIN_ALL, true);
 }
 
 static void test_quiesce_co_drain_all(void)
 {
-    call_in_coroutine(test_quiesce_drain_all);
+    BlockBackend *blk = test_setup();
+    call_in_coroutine(test_quiesce_co_drain_all_entry);
+    blk_unref(blk);
+}
+
+static void coroutine_fn test_quiesce_co_drain_entry(void)
+{
+    BlockBackend *blk = blk_all_next(NULL);
+    test_quiesce_common(blk, BDRV_DRAIN, false);
 }
 
 static void test_quiesce_co_drain(void)
 {
-    call_in_coroutine(test_quiesce_drain);
+    BlockBackend *blk = test_setup();
+    call_in_coroutine(test_quiesce_co_drain_entry);
+    blk_unref(blk);
 }
 
 static void test_nested(void)