Calling aio_poll() directly may have been fine previously, but this is
the future, man! The difference between an aio_poll() loop and
BDRV_POLL_WHILE() is that BDRV_POLL_WHILE() releases the AioContext
around aio_poll().
This allows the IOThread to run fd handlers or BHs to complete the
request. Failure to release the AioContext causes deadlocks.
Using BDRV_POLL_WHILE() partially fixes a 'savevm' hang with -object
iothread.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
---
block/io.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/block/io.c b/block/io.c
index cc56e90..f0041cd 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2031,9 +2031,7 @@ bdrv_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
int64_t pos,
Coroutine *co = qemu_coroutine_create(bdrv_co_rw_vmstate_entry, &data);
bdrv_coroutine_enter(bs, co);
- while (data.ret == -EINPROGRESS) {
- aio_poll(bdrv_get_aio_context(bs), true);
- }
+ BDRV_POLL_WHILE(bs, data.ret == -EINPROGRESS);
return data.ret;
}
}
--
2.9.3
