# K1666–K1670 ordered writes and publication

The bounded writer issues data OUT, FLUSH, log OUT, FLUSH, commit OUT and FLUSH
in that order. It publishes metadata only after successful completion of the
last flush. Publishing in the initial or failed state is rejected without
mutation. An error at any I/O boundary stops further requests and permanently
refuses publication and retries through that writer instance.

Host tests observe the complete device operation sequence and inject failure at
all six boundaries. An omitted-publication-guard mutant must fail. The guest
acceptance requires real OUT/FLUSH completions against a disposable disk, an
independent device trace and post-run disk bytes; a host model alone cannot
close this development guest gate.

Emulated flush completion establishes the observed QEMU/host boundary only.
It does not establish physical power-loss safety, general filesystem journal
recovery, concurrent writers, torn-sector handling or canonical product release.
The production-write build restriction remains in force.