Subject: Re: /sbin/umount should support umount_* (PR#698)
To: Bill Studenmund <wrstuden@netbsd.org>
From: Greywolf <greywolf@starwolf.com>
List: current-users
Date: 03/11/2003 20:58:02
Thus spake Bill Studenmund ("BS> ") sometime Today...

BS> That I got. But he wanted unmount to send the signal. I think the kernel
BS> (specifically the fs code in the kernel) to send it.
BS>
BS> I'm envisioning the fs and the helper keeping a control socket open during
BS> the lifetime of the mount, if for no other reason than to receive this
BS> signal. Note also that the "signal" would be a socket write, not a SIG.

Okay, now what happens if the helper actually gets kill()ed somehow?
Will the filesystem automagically unmount?  If there are processes
with something attached to said filesystem, do they go *poof*?
Does the kernel panic?  Or is this "implementation-defined behaviour"?

BS> The big difference is that the kernel can notice the helper going away, so
BS> 1) you won't get the signal sent to the wrong process, and 2) the file
BS> system itself can react to the helper disapearing.


				--*greywolf;
--
"I didn't get where I am today without using NetBSD."