On Fr, 02.03.18 10:22, Hongzhi, Song (hongzhi.s...@windriver.com) wrote:
> On 2018年03月01日 17:50, Lennart Poettering wrote:
> > On Do, 01.03.18 14:44, Hongzhi, Song (hongzhi.s...@windriver.com) wrote:
> > > Thank you very much. It dose work.
> > >
> > > Would you tell me that how the '--no-block' works,
> > "systemd-mount" talks to systemd (i.e. PID 1) to issue mount/automount
> > operations. By default it will do so synchronously, thus blocking
> > until the mount is established. If you specify "--no-block" then you
> > turn off this synchronous behaviour, and instead request asynchronous
> > behaviour, where the rule will just request the operation to be
> > executed, but won't wait for it to finish. When you invoke
> > "systemd-mount" from a udev rule then using "--no-block" is a
> > necessity to avoid a deadlock. That's because PID 1 won't operate on a
> > device to mount before udev reported it to be fully availabled and
> > probed.
> Do you mean that udev doesn't report device to be fully availabled
> and probed until systemd-mount returns?
Yes. All programs configured in udev rules files need to finish before
udev reports the device to its clients to be fullyprobed and ready.
Lennart Poettering, Red Hat
systemd-devel mailing list