Since we use bdrv_do_drained_begin/end() for bdrv_drain_all_begin/end(),
coroutine context is automatically left with a BH, preventing the
deadlocks that made bdrv_drain_all*() unsafe in coroutine context. We
can consider it compatible now the latest, after having removed the old
polling code as dead code.

Enable the coroutine test cases for bdrv_drain_all().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/test-bdrv-drain.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index cd870609c5..6de525b509 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -233,6 +233,11 @@ 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);
@@ -289,6 +294,11 @@ 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);
@@ -795,7 +805,8 @@ int main(int argc, char **argv)
     g_test_add_func("/bdrv-drain/driver-cb/drain_subtree",
                     test_drv_cb_drain_subtree);
 
-    // XXX bdrv_drain_all() doesn't work in coroutine context
+    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);
@@ -806,7 +817,8 @@ int main(int argc, char **argv)
     g_test_add_func("/bdrv-drain/quiesce/drain_subtree",
                     test_quiesce_drain_subtree);
 
-    // XXX bdrv_drain_all() doesn't work in coroutine context
+    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);
-- 
2.13.6

On 04/11/2018 11:39 AM, Kevin Wolf wrote:
> Since we use bdrv_do_drained_begin/end() for bdrv_drain_all_begin/end(),
> coroutine context is automatically left with a BH, preventing the
> deadlocks that made bdrv_drain_all*() unsafe in coroutine context. We
> can consider it compatible now the latest, after having removed the old

s/the latest/at last/ ?

> polling code as dead code.
> 
> Enable the coroutine test cases for bdrv_drain_all().
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  tests/test-bdrv-drain.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

On Wed, Apr 11, 2018 at 06:39:26PM +0200, Kevin Wolf wrote:
> Since we use bdrv_do_drained_begin/end() for bdrv_drain_all_begin/end(),
> coroutine context is automatically left with a BH, preventing the
> deadlocks that made bdrv_drain_all*() unsafe in coroutine context. We
> can consider it compatible now the latest, after having removed the old
> polling code as dead code.
> 
> Enable the coroutine test cases for bdrv_drain_all().
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  tests/test-bdrv-drain.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>