Re: Fixing swap1_stop

["Ian D. Leroux" <idleroux%fastmail.fm@localhost>]

On Wed, Aug 23, 2017, at 07:02, Christos Zoulas wrote:
> In article <C32A9472-EFC7-438D-B7F8-F806242C1745%eis.cs.tu-bs.de@localhost>,
> J. Hannken-Illjes <hannken%eis.cs.tu-bs.de@localhost> wrote:
> >
> >> On 19. Aug 2017, at 14:20, Christos Zoulas <christos%zoulas.com@localhost>
> >> wrote:
> >>
> >> On Aug 19,  1:04pm, hannken%eis.cs.tu-bs.de@localhost ("J. Hannken-Illjes")
> >> wrote: -- Subject: Re: Fixing swap1_stop
> >>
> >> | A long time ago forced unmounts tried to change open block device
> >> | nodes to anonymous (not attached to a file system) nodes.  This
> >> | was racy and has been removed.
> >> |
> >> | With the recent changes to the VFS subsystem it should be
> >> | possible to bring this behaviour back and instead of destroying
> >> | open device nodes a forced unmount would detach them from the
> >> | file system and keep them active.
> >> |
> >> | Did you mean something like this?
> >>
> >> Yes exactly that.
> >
> >Committed and pullup to -8 requested:
> >
> >src/sys/kern/vfs_vnode.c r1.97, r1.98
> >src/sys/miscfs/deadfs/dead_vfsops.c r1.8 src/sys/kern/vfs_mount.c
> >r1.67 src/sys/sys/vnode_impl.h r1.16
>
> Excellent, so now swap1_stop works as is :-)

In which case bin/51019 can be closed.

I might still argue for moving the umount command into swap2_stop, on
the grounds that the rationale for unmounting tmpfs filesystems before
removing swap applies equally whether that swap is backed by a file or
by a block device, but that's a separate discussion.

Thanks all for an instructive and constructive discussion, and for
writing solutions while I was still stuck thinking about problems.

-- IDL