Re: [PATCH 00/10] btrfs-progs: my libbtrfsutil patch queue

[Omar Sandoval <osandov@osandov.com>]

On Mon, Nov 26, 2018 at 05:18:12PM +0100, David Sterba wrote:
> On Tue, Nov 13, 2018 at 11:46:55PM -0800, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > Hi,
> > 
> > This series contains my backlog of libbtrfsutil changes which I've been
> > collecting over the past few weeks.
> > 
> > Patches 1-4 are fixes. Patches 5-6 add functionality to the unit tests
> > which is needed for patches 7-8. Patches 7-8 add support for the
> > unprivileged ioctls added in Linux 4.18; more on those below. Patch 9
> > bumps the library version. Patch 10 adds documentation for the available
> > API along with examples.
> > 
> > Patches 7-8 are based on Misono Tomohiro's previous patch series [1],
> > with a few important changes.
> > 
> > - Both subvolume_info() and create_subvolume_iterator() now have unit
> >   tests for the unprivileged case.
> > - Both no longer explicitly check that top == 0 in the unprivileged
> >   case, since that will already fail with a clear permission error.
> > - Unprivileged iteration is much simpler: it uses openat() instead of
> >   fchdir() and is based more closely on the original tree search
> >   variant. This fixes a bug in post-order iteration in Misono's version.
> > - Unprivileged iteration does _not_ support passing in a non-subvolume
> >   path; if this behavior is desired, I'd like it to be a separate change
> >   with an explicit flag.
> 
> Series merged to devel, thanks.

Thanks!

> I've added link from the main README now
> that there's the API documentation.

Ah, great idea.

> The test-libbtrfsutil is missing from the travis CI for some reason, I
> was about to add it.  So far the testing environment does not provide
> 'umount' that knows about '-R' so the tests fail. I'll have a look if
> there's a newer base image provided, otherwise a workaround would be
> necessary.

It looks like it was added to util-linux in v2.23 back in 2013. Or maybe
the base image uses busybox? I believe that umount from busybox doesn't
have -R.

> As for the unprivileged subvolume listing ioctls, the functionality in
> the util library is self-contained and the interface is up to you to
> design properly, so this does not depend on the 'btrfs subvolume list'
> command. That one has unfortunately not bubbled high enough in my todo.

That comment is mostly for Misono, since the original version had that
functionality, probably for the subvolume list command.