Re: add file system helpers that take kernel pointers for the init code v4

[Al Viro]

On Tue, Jul 28, 2020 at 06:33:53PM +0200, Christoph Hellwig wrote:
> Hi Al and Linus,
> 
> currently a lot of the file system calls in the early in code (and the
> devtmpfs kthread) rely on the implicit set_fs(KERNEL_DS) during boot.
> This is one of the few last remaining places we need to deal with to kill
> off set_fs entirely, so this series adds new helpers that take kernel
> pointers.  These helpers are in init/ and marked __init and thus will
> be discarded after bootup.  A few also need to be duplicated in devtmpfs,
> though unfortunately.
>
> The series sits on top of my previous
> 
>   "decruft the early init / initrd / initramfs code v2"

Could you fold the fixes in the parent branch to avoid the bisect hazards?
As it is, you have e.g. "initd: pass a non-f_pos offset to kernel_read/kernel_write"
that ought to go into "initrd: switch initrd loading to struct file based APIs"...