Packet allocation failure

[jklmnn]

When submitting larger amounts of packets the allocation fails with

Error: Uncaught exception of type 'Genode::Packet_stream_source<Genode::Packet_stream_policy<Block::Packet_descriptor, 256u, 256u, char> >::Packet_alloc_failed'

This doesn't seem to be taken into account by the ready function which checks if the submit queue can take more requests. Aside from the check I'm not sure if a signal handler is in place for "packets can be allocated again".