Bug#686895: initscripts: /forcefsck: fsck -f undefined (e2fsck-ism)

[Pierre Ynard]

> > As you convincingly remarked below, we may want honor `test -f /forcecheck'
> > for every filesystem, whose `fsck' supports `-f' option. As far as I
> > follow the thread, it is:
> >
> >     ext2 ext3 ext4 reiserfs
>
> Interesting that acceptance of that parameter is so low.

fsck.minix supports it too. I don't use many filesystems and don't have
many tool suites installed so I really wouldn't know how widespread it
is.

> > But I really want to have some transition plan to get rid of
> > /forcecheck, something like:
>
> … you might like that tune2fs can now (1.45.0-1, not yet in
> buster, officially not likely to make it but we can hope) set
> a flag force_fsck that next boot’s auto e2fsck will honour.
> I’m assuming this works for ext2/ext3/ext4; ask tytso if unsure.

You may want to look at #470956 for related reasons and discussions.
/fastboot and /forcefsck are created by `shutdown -f` and `shutdown -F`
respectively. I like the idea that instead of this interface, it should
call tune2fs to set that flag. Or rather, if that doesn't belong inside
the shutdown binary, it could create /forcefsck or /run/forcefsck, which
would then be checked by a script in runlevel 0 or 6 that calls tune2fs
on the relevant filesystems.

We could use that script any time we want (like in runlevel S too) to
print deprecation warnings to assist in the transition.

-- 
Pierre Ynard