[systemd-devel] Antw: Re: Antw: Re: Antw: failing unmounts during reboot

[Ulrich Windl]

>>> Lennart Poettering <lennart at poettering.net> schrieb am 29.07.2019 um 13:55
in
Nachricht <20190729115524.GB19185 at gardel-login>:
> On Mo, 29.07.19 08:16, Ulrich Windl (Ulrich.Windl at rz.uni-regensburg.de) 
> wrote:
> 
>> >>> Lennart Poettering <lennart at poettering.net> schrieb am 25.07.2019 um
13:37
>> in
>> Nachricht <20190725113724.GC12912 at gardel-login>:
>> > On Do, 25.07.19 12:52, Ulrich Windl (Ulrich.Windl at rz.uni‑regensburg.de)
>> wrote:
>> >
>> >> > "try to kill all processes using a filesystem before unmounting it"
>> >> > isn't that easy when it comes to namespaces, "lsof" even don't tell
you
>> >> > the root cause preventing unmount but the ernel still refuses to do
so
>> >>
>> >> Does systemd even try to use lsof?
>> >
>> > No, of course not. We tend to avoid hacks like that.
>>
>> And just repeating the unmount without further actions is not a
>> hack?
> 
> Hmm? we tend to give up when we can't unmount something, log about it
> and go on. We also have a second shutdown phase, which is a dumb and
> brutal kill/umount loop that kills remaining processes and removes
> mounts in a tight loop until nothing changes anymore. This second
> phase is a safety net only though: it takes care of stuff that somehow
> survive the first phase, i.e. the clean phase.
> 
>> Why not stop when unmount fails?
> 
> We do that.

But it seems to be a better idea for the second phase to kill processes
blocking unmount.

> 
> Lennart
> 
> --
> Lennart Poettering, Berlin