Re: [fuse-devel] Do I need to support both - libfuse2 and libfuse3 in my application in order to work on more Linux distros, in case I deploy libfuse with my application

[Antonio SJ M. <tra...@sp...>]

 > My concern was - can I use and deploy libfuse3 on older Linux 
distros, like CentOS 6, for example?

Yes. However, the new build system used in libfuse3 has, in my 
experience, failed on older platforms due to not having a recent enough 
version of Python 3. So you'll possibly need to manage that yourself 
unless that's been fixed.

 > This will be necessary only if we don't deploy a build for libfuse, 
correct?

Correct.

To your last questions: Yes. If you manage it all yourself it should all 
work fine... given the issues I've mentioned prior. There isn't a 
listing of kernel version to libfuse version compatibility. Most if not 
all versions of libfuse are backwards compatible to in some cases very 
old kernels. All new features are optional and established at the 
FUSE_INIT phase.

On 10/1/2019 6:53 AM, Cyril Cyrov wrote:
> Hi,
>
> Here's an introduction for this thread:
> https://github.com/libfuse/libfuse/issues/460
>
> Long story short:
> Q: How can I support both libfuse2 and libfuse3 in order to make my
> app work on more Linux distos?
> A: You don't need to do that.
>
> So, continuing the discussion here.
>
> ---
>
> My misunderstanding comes from the fact, that I though there are two
> different kernel modules for the two versions and that libfuse3 can
> only work on Linux distros, which do have `fuse3` package installed
> (and these distros are just a few). This misunderstanding was also
> supported by the fact, that libfuse3 needs fusermount3 in order to
> create a mountpoint.
>
> Another miscommunication occurred by the different interpretation of
> "patching the fuse implementation" and "embedding" fuse.
>
> We do deploy a libfuse shared object with our application. So, this is
> not an issue at all.
>
> My concern was - can I use and deploy libfuse3 on older Linux distros,
> like CentOS 6, for example?
>
> What confuses me further is that I cannot find any matching between
> libfuse versions and kernel versions, explaining which libfuse version
> is compatible with which kernel versions.
>
> ---
>
> @trapexit
>> Then you'll have to deal with the distro's support
> By "avoid patching the fuse implementation" I didn't mean I don't want
> to deploy fuse build, I just misunderstood you and thought that you
> suggest actually making some source patch in order to "merge" them
> somehow. Sorry for the misleading.
>
> ---
>
> @Nikratio:
>> "Why don't you ship two binaries (one for libfuse2 and one for libfuse3) together with a small wrapper that picks with version to use?"
> This will be necessary only if we don't deploy a build for libfuse, correct?
>
> ---
>
> So, I'll try to wrap things up, please correct me if I'm wrong - appreciated!
>
> We can actually use only libfuse3 and if we deploy it (or statically
> link it in our application) this should work fine all Linux distros,
> which otherwise would work fine with libfuse2. Is that correct?
> Also, is there a way to find out which libfuse3 features depend on
> which Linux kernel, in order to work fine?
>
> Thanks,
> Kiril
>
>