On 9/11/19 11:15 AM, Sergio Lopez wrote: > 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 in > blk_aio_attached(). > > RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1748253 > Signed-off-by: Sergio Lopez <s...@redhat.com> > --- > nbd/server.c | 2 ++ > 1 file changed, 2 insertions(+)
I'd like a second opinion from Kevin, but the description makes sense to me. I'm happy to queue this through my NBD tree. Reviewed-by: Eric Blake <ebl...@redhat.com> > > diff --git a/nbd/server.c b/nbd/server.c > index 10faedcfc5..51322e2343 100644 > --- a/nbd/server.c > +++ b/nbd/server.c > @@ -471,6 +471,7 @@ static int nbd_negotiate_handle_export_name(NBDClient > *client, > QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); > nbd_export_get(client->exp); > nbd_check_meta_export(client); > + qio_channel_attach_aio_context(client->ioc, client->exp->ctx); > > return 0; > } > @@ -673,6 +674,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, > uint16_t myflags, > QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); > nbd_export_get(client->exp); > nbd_check_meta_export(client); > + qio_channel_attach_aio_context(client->ioc, exp->ctx); > rc = 1; > } > return rc; > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org
signature.asc
Description: OpenPGP digital signature
