Re: [GIT PULL] vfs tmpfs

[Linus Torvalds <torvalds@linux-foundation.org>]

On Fri, 15 Nov 2024 at 06:07, Christian Brauner <brauner@kernel.org> wrote:
>
> This adds case-insensitive support for tmpfs.

Ugh.

I've pulled this, but I don't love it.

This pattern:

    if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
        d_add(dentry, inode);
    else
        d_instantiate(dentry, inode);

needs an explanation, and probably a helper.

And

>  include/linux/shmem_fs.h            |   6 +-
>  mm/shmem.c                          | 265 ++++++++++++++++++++++++++++++++++--

I'm starting to think this should be renamed and/or possibly split up
a bit. The actual path component handling functions should be moved
out of mm/shmem.c.

The whole "mm/shmem.c" thing made sense back in the days when this was
mainly about memory management functions with some thing wrappers for
exposing them as a filesystem, and tmpfs was kind of an odd special
case.

Those thin wrappers aren't very thin any more, and "shmem" is becoming
something of a misnomer with the actual filesystem being called
"tmpfs".

We also actually have *two* different implementations of "tmpfs" -
both in that same file - which is really annoying. The other one is
based on the ramfs code.

Would it be possible to try to make this a bit saner?

           Linus