On creation, the export's AioContext is set to the same one as the BlockBackend, while the AioContext in the client QIOChannel is left untouched.
As a result, when using data-plane, nbd_client_receive_next_request() schedules coroutines in the IOThread AioContext, while the client's QIOChannel is serviced from the main_loop, potentially triggering the assertion at qio_channel_restart_[read|write]. To fix this, as soon we have the export corresponding to the client, we call qio_channel_attach_aio_context() to attach the QIOChannel context to the export's AioContext. This matches with the logic at blk_aio_attached(). RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1748253 Signed-off-by: Sergio Lopez <s...@redhat.com> --- Changelog v2: - Attach the channel once after negotiation completes, avoiding duplication. (thanks Kevin Wolf). --- nbd/server.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/nbd/server.c b/nbd/server.c index 28c3c8be85..31d624e146 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1297,6 +1297,11 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) return ret; } + /* Attach the channel to the same AioContext as the export */ + if (client->exp && client->exp->ctx) { + qio_channel_attach_aio_context(client->ioc, client->exp->ctx); + } + assert(!client->optlen); trace_nbd_negotiate_success(); -- 2.21.0
