[Pkg-zfsonlinux-devel] Bug#962424: Bug#962424: zfsutils-linux: systemd zfs-mount-generator breaks boot if multiple datasets have the same mountpoint

[Wxcafé]

Only one pool containing both the actual datasets and the ones with
canmount=noauto (backups) that have the same mountpoint (there's a
separate boot pool but it doesn't matter in this circumstance)

I don't use zfs-import-cache since it's a single pool that contains the
root so it's in the kernel cmdline and imported at that point.

I'll try and find the time to reproduce in a VM this week...

On Tue, 2020-06-09 at 17:06 -0500, Richard Laager wrote:
> On 6/7/20 3:12 PM, wxcafe wrote:
> > The systemd zfs-mount-generator script
> > (/lib/systemd/system-generators/zfs-mount-generator) can break
> > system
> > boot if there are multiple datasets with the same mountpoint,
> > because it
> > ignores the zfs property canmount=noauto.
> 
> It certainly does not "ignore" canmount=noauto. There's all kinds of
> logic in the generator to deal with canmount=noauto.
> 
> > I store backups on my system and after upgrading the system
> > wouldn't
> > boot anymore because while my backups are canmount=noauto, the
> > generator
> > was trying to mount multiple datasets to the same mountpoints (/,
> > /usr/,
> > ...) which obviously breaks... everything.
> 
> If you have datasets marked as canmount=on, they should take
> precedence
> over any marked canmount=noauto for the same mountpoint.
> 
> Are there multiple pools involved here, or just one?
> 
> Can you provide a copy of your cache file(s) from /etc/zfs/zfs-
> list.cache?
> 
-- 
Wxcafé <wxcafe at wxcafe.net>