Re: [PATCH 08/14] libfuse: connect high level fuse library to fuse_reply_attr_iflags

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Jul 29, 2025 at 09:50:30AM +0200, Amir Goldstein wrote:
> On Tue, Jul 29, 2025 at 7:35 AM Darrick J. Wong <djwong@kernel.org> wrote:
> >
> > On Thu, Jul 24, 2025 at 09:56:16PM +0200, Amir Goldstein wrote:
> > > > > Also a bit surprising to see all your lowlevel work and then fuse high
> > > > > level coming ;)
> > > >
> > > > Right now fuse2fs is a high level fuse server, so I hacked whatever I
> > > > needed into fuse.c to make it sort of work, awkwardly.  That stuff
> > > > doesn't need to live forever.
> > > >
> > > > In the long run, the lowlevel server will probably have better
> > > > performance because fuse2fs++ can pass ext2 inode numbers to the kernel
> > > > as the nodeids, and libext2fs can look up inodes via nodeid.  No more
> > > > path construction overhead!
> > > >
> > >
> > > I was wondering how well an LLM would be in the mechanical task of
> > > converting fuse2fs to a low level fuse fs, so I was tempted to try.
> > >
> > > Feel free to use it or lose it or use as a reference, because at least
> > > for basic testing it seems to works:
> > > https://github.com/amir73il/e2fsprogs/commits/fuse4fs/
> >
> > Heh, I'll take a closer look in the morning, but it looks like a
> > reasonable conversion.  Are you willing to add a "Co-developed-by" tag
> > per Sasha's recent proposal[1] if I pull it in?
> >
> > [1] https://lore.kernel.org/lkml/20250727195802.2222764-1-sashal@kernel.org/
> >
> 
> Sure. Added and pushed.
> 
> FYI, some behind the scenes for the interested:
> - The commit titles roughly align to the LLM prompts that I used

Heh.  For reproducibility, I wonder if it ought to be a good idea for
the commit messages to contain the prompts fed to the LLM?  Maybe I'll
suggest that to Sasha.

> - One liner commit message "LLM aided conversion" means it's mostly hands off
> - Anything other than the one liner commit message suggests human intervention,
>   that was usually done to make the code more human friendly, the patches
>   diffstat smaller and frankly, to match my human preferences

Oh, I was hoping you'd say that you reprompted all the way to working
patches, but I suppose AIs are rather expensive to operate.

> - I did not let the agent touch git at all and I took care of applying
> fixes into
>   respective patches manually when needed
> - The code compiles, but obviously does not work mid series

ha lol :)

> - The most interesting part was the last commit of tests, when the agent
>   was testing and fixing its own conversion. This comes with some nice
>   observations about machine-human collaboration in this context, for example:
> - The machine figured out the need to convert
>   EXT2_ROOT_INO <=> FUSE_ROOT_INO by itself from self testing,
>   created the conversion helpers and used them in lookup and some other
>   methods

<nod> I think Miklos mentioned that I could work around that by allowing
fuse servers to set the root nodeid with a mount option.

> - Obviously, it would have figured out that the conversion helpers need to
>   be used for all methods sooner or later during self testing, but its self
>   reflecting cycles can be so long and tedious for an observation that
>   look so trivial, so a nudge from human "convert all methods" really helps
>   speeding things up, at least with the agent/model/version that I used

Well we could just do the usual "make main exit(1) for the duration of
the chur^Wchanges" trick to avoid bisection bombs. :)

> I think that language/API conversion is one of the tasks where LLM
> can contribute most to humans, as long the work is meticulously
> reviewed by a human that has good knowledge of both source and
> target language/dialect.

Yeah.  Though first I need to lay the groundwork by figuring out if
macfuse/freebsd fuse actually provide the lowlevel library.  If not,
then per Ted's direction I'll have to implement both. :/

Maybe I'll try the Oracle codebot this week, though I think they said it
only knows Python.  Anyway, thanks for the inputs. :)

--D

> Thanks,
> Amir.
>