It seems that bdrv_open_driver() forgot to create a coroutine
where to call bs->drv->bdrv_co_drain_begin(), a callback
marked as coroutine_fn.
Because there is no active I/O at this point, the coroutine
should end right after entering, so the caller does not need
to poll until it is finished.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
block.c | 36 +++++++++++++++++++++++++++++++-----
1 file changed, 31 insertions(+), 5 deletions(-)
diff --git a/block.c b/block.c
index 5311b21f8e..d2b2800039 100644
--- a/block.c
+++ b/block.c
@@ -1637,12 +1637,34 @@ out:
g_free(gen_node_name);
}
+typedef struct DrainCo {
+ BlockDriverState *bs;
+ int ret;
+} DrainCo;
+
+static void coroutine_fn bdrv_co_drain_begin(void *opaque)
+{
+ int i;
+ DrainCo *co = opaque;
+ BlockDriverState *bs = co->bs;
+
+ for (i = 0; i < bs->quiesce_counter; i++) {
+ bs->drv->bdrv_co_drain_begin(bs);
+ }
+ co->ret = 0;
+}
+
static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv,
const char *node_name, QDict *options,
int open_flags, Error **errp)
{
Error *local_err = NULL;
- int i, ret;
+ int ret;
+ Coroutine *co;
+ DrainCo dco = {
+ .bs = bs,
+ .ret = NOT_DONE,
+ };
GLOBAL_STATE_CODE();
bdrv_assign_node_name(bs, node_name, &local_err);
@@ -1690,10 +1712,14 @@ static int bdrv_open_driver(BlockDriverState *bs,
BlockDriver *drv,
assert(bdrv_min_mem_align(bs) != 0);
assert(is_power_of_2(bs->bl.request_alignment));
- for (i = 0; i < bs->quiesce_counter; i++) {
- if (drv->bdrv_co_drain_begin) {
- drv->bdrv_co_drain_begin(bs);
- }
+ if (drv->bdrv_co_drain_begin) {
+ co = qemu_coroutine_create(bdrv_co_drain_begin, &dco);
+ qemu_coroutine_enter(co);
+ /*
+ * There should be no reason for drv->bdrv_co_drain_begin to wait at
+ * this point, because the device does not have any active I/O.
+ */
+ assert(dco.ret != NOT_DONE);
}
return 0;