search for: extended_head

...l for interoperability testing, it may be worth > > adding a new set_strict_mode control knob to explicitly enable the > > client to intentionally violate the protocol (the testsuite added in > > this patch would then be updated to match). > > > > At this point, h->extended_headers is permanently false (we can't > > enable it until all other aspects of the protocol have likewise been > > converted). > > > > Support for using FLAG_PAYLOAD_LEN with NBD_CMD_BLOCK_STATUS is less > > fundamental, and deserves to be in its own patch. > >...

This is the culmination of the previous patches' preparation work for using extended headers when possible. The new states in the state machine are copied extensively from our handling of OPT_STRUCTURED_REPLY. The next patch will then expose a new API nbd_opt_extended_headers() for manual control. At the same time I posted this patch, I had patches for qemu-nbd to support extended headers as server (nbdkit is a bit tougher). The next patches will add some interop tests that pass when using a new enough qemu-nbd, showing that we have cross-project interoperability a...