I recently got this merged upstream and wanted to share the repository. Bolting a JBD2 WAL onto Gnu Hurd was an interesting learning experience

Off-topic, but does the Hurd help with the situation with ZFS compared to Linux? My understanding is that the ZFS code is licensed under the CDDL, which is incompatible with the GPL, so it can't be used in the Linux kernel. But if Hurd file system drivers are separate userspace programs, there might not be a conflict, since there is no "linking" or close-coupling with GPL code?