On Mi, 21.12.22 12:12, Demi Marie Obenour (demiobenour(a)gmail.com) wrote:
> At least for the systemd stuff, we carefully made sure that our
access
> patterns to the ESP both from sd-boot/sd-stub and from userspace are
> by default as minimal and robust as we can make them, to minimize
> chance of corruption, given that vfat is not particularly good with
> that. (i.e. we sync a lot, and the whole ESP mount is by default an
> autofs instance with an extremely short idle timeout so that it
> basically remains unmounted — and thus — clean during almost all
> times).
>
> Anyway, if you want to know more about choice of the fs for /boot/,
> see my ideas here:
>
>
https://0pointer.net/blog/linux-boot-partitions.html
>
> Lennart
Does vfat support atomic rename? Is it possible to atomically upgrade
a bootloader/UKI/etc?
Depends on the fs driver. But yeah, the filename is stored at exactly
one place, and hence typically a single-sector update is
possible. (well, within bounds: for example if you rename a file from
a short filename to a long one, fs driver might need to allocate a
bunch of separate long file name dir entries, which might then span
multiple sectors)
Lennart
--
Lennart Poettering, Berlin