[Libguestfs] [PATCH nbdkit 0/4] New plugin: Add linuxdisk plugin.

Turns out Japanese trains are good for coding! In supermin we have a bunch of code to create the libguestfs appliance. It creates it directly using libext2fs (part of e2fsprogs). We can use the same technique to create ext2 virtual disks in nbdkit, which is what this new plugin does. Why a new plugin instead of modifying the floppy plugin? See the 4/4 commit message for an explanation. The first 3 patches are pretty uncontroversial refactoring. The 4th patch contains the plugin and tests. It's probably best to start with the commit message and the included man page. This is quick even for relatively large filesystems containing large numbers of small files. Here's an example for the nbdkit source code (including the .git directory): $ time ./nbdkit --filter=partition -U - linuxdisk . partition=1 --run 'qemu-img convert $nbd /var/tmp/ext2fs.img' real 0m1.314s user 0m0.424s sys 0m0.889s $ ls -lh /var/tmp/ext2fs.img -rw-r--r--. 1 rjones rjones 351M Feb 19 07:44 /var/tmp/ext2fs.img The tests + valgrind pass on Fedora 29 & RHEL 7. Rich.