[systemd-devel] [PATCH 2/2] fsck: Add support for EFI variable based fsck indication

[Lennart Poettering]

On Sun, 15.03.15 21:30, Zbigniew Jędrzejewski-Szmek (zbyszek at in.waw.pl) wrote:

> So this used to to be possible for ext4, by setting "mount count" one
> below the "mount limit". But "mount limit" now defaults to disabled, so
> this stopped being possible.
> 
> Also, this suffers from the same problem that setting the flag requires modyfing
> the filesystem. Just touching the super block is not that bad, but still,
> doing it externally seems nicer.

Another option might be to define a bit for this in the GPT partition
header, and then write only to that. The file system stays unmodified
then. This would work for all file systems, and we could collect this
easily in systemd via udev... Operating systems such as ChromeOS write
to the partition table all the time, and maintain boot counters and
suchlike there, so this might be an option?

Of course, this only works for GPT systems, i.e. modern systems, and
modern systems probably wouldn't run ext234 anyway, so maybe it's not
worth it... Actually neither xfs nor btrfs nor reiserfs appear to
require an fsck still, it's only ext234 and vfat. And I figure it's
not worth fixing this for ext234 now...

Lennart

-- 
Lennart Poettering, Red Hat