Re: VOP_PUTPAGE ignores mount_nfs -o soft,intr

[David Holland <dholland-tech%netbsd.org@localhost>]

On Sat, Jun 20, 2015 at 12:30:28AM +0000, Christos Zoulas wrote:
 > >Sure. But it also doesn't mean that there should be cases where I/O to
 > >the filesystem hangs uninterruptibly.
 > >
 > >Nothing is supposed to hang in tstile; therefore, this wait is
 > >incorrect...
 > 
 > Ok, what is it supposed to do? Does it fail? Give up? Get interrupted
 > and keep looping?

I don't know; maybe time out and release/retake the vnode lock so
other threads can run?

 > > > Having said that, yes it is a problem that you need to reboot
 > > > because an NFS server is gone, and we should make umount -f work
 > > > properly in that case. I don't think that we should introduce umount
 > > > -l (like linux) unless there is a compelling reason to do so.
 > >
 > >I would say we want umount -l, but it's both not trivial and not a
 > >solution to this problem.
 > 
 > My understanding that umount -l hides the mount, but does not deallocate
 > resources it can't. So it does not look that hard to me.

It requires splitting struct mount into two pieces, one for the
filesystem and one for the mount of the filesystem. This isn't
entirely trivial.

-- 
David A. Holland
dholland%netbsd.org@localhost