[systemd-devel] Masking mount units

Lennart Poettering lennart at poettering.net
Tue Nov 19 08:43:56 UTC 2024


On Di, 19.11.24 01:45, Nils Kattenbeck (nilskemail at gmail.com) wrote:

> On Tue, Nov 19, 2024 at 1:00 AM Lennart Poettering
> <lennart at poettering.net> wrote:
> >
> > On Do, 14.11.24 14:25, Phillip Susi (phill at thesusis.net) wrote:
> >
> > > Lennart Poettering <lennart at poettering.net> writes:
> > >
> > > > the BLKFLSBUF ioctl() works fine on block device fds open for read only.
> > >
> > > Oh, I might have to change that to use a read only open then.
> > >
> > > > I am not following anymore. As *long* *as* *the* lock is taken the
> > > > auto mounting doesn't happen. Once you release the lock then
> > > > everything will be reprobed and work as it always worked, including
> > > > auto-mounting.
> > >
> > > It is not about delaying the auto mounting, but *preventing it*
> > > entirely.
> >
> > It *is* prevented. While you keep the lock open *no* events are
> > propagated from udev to its clients, hence no automounts will take
> > place. Any kernel reported event that happen while you keep the lock
> > will basically be eaten up by udev and not propagated on to rest of
> > userspace. They are sent to /dev/null if you so will. When you release
> > the lock once you are fully done (which might as well be 3h later, if
> > you like) however, then a single *new* event is *synthesized*, to get
> > the rest of userspace updated again on things. And yes, that *might*
> > cause userspace to automount things, and other stuff. But that's fine,
> > you explicit indicated you are now done with the device, hence others
> > can consume it again.
>
> I think you have been talking past each other for the last dozen mails.
> I am quite sure that Philip Susi not only wants to prevent auto-mounts
> while gparted is working with the filesystem but also afterwards,
> i.e. they also want to suppress the synthetic event you are talking
> about.

Huh? Even after? Like, *forever*??? What's the point of that? Is
gparted supposed to break your system for good and render your block
devices unusable?

I thought it was a partitioner, but I might have gotten that wrong?

Lennart

--
Lennart Poettering, Berlin


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