Re: [PATCH] erofs: fix file-backed mounts over FUSE

[Gao Xiang]

On 2024/11/14 14:34, Al Viro wrote:
> On Thu, Nov 14, 2024 at 02:23:27PM +0800, Gao Xiang wrote:
>
> > > 3) AFAICS, (buf->kmap_type == EROFS_KMAP) == (buf->base != NULL).  What's
> > > the point of having that as a separate field?
> >
> > Once buf->kmap_type has EROFS_KMAP and EROFS_KMAP_ATOMIC, but it
> > seems that it can be cleaned up now.
> >
> > I will clean up later but it's a seperate story.
> >
> > > 4) Why bother with union?  Just have buf->file serve as your buf->use_fp
> > > and be done with that...
> >
> > I'd like to leave `struct erofs_buf` as small as possible since
> > it's on stack.
>
> enum + bool eats at least as much as a pointer, and if it's on stack...
> an extra word is really noise - it's not as if you had a plenty of
> those in the current call chain at any given point.

Yeah, enum can be avoided now, I will clean up this enum
as a seperate effort.

Thanks,
Gao Xiang