[systemd-devel] remote-fs ordering, iSCSI and _netdev

[Karel Zak]

On Tue, Oct 28, 2014 at 02:29:35AM +0100, Lennart Poettering wrote:
> On Mon, 27.10.14 14:10, Chris Leech (cleech at redhat.com) wrote:
> 
> > So for any mounts to remote block devices (unlike remote file system
> > protocols which are detected by the fs name), unless there is an fstab
> > entry at the time fstab-generator is run they get treated like local fs
> > mounts and connectivity to the storage target may be disrupted before
> > unmounting (possibly resulting in file system errors).
> > 
> > I'm currently at a loss for how to handle this, other than to claim that
> > if filesystems are going to be left mounted they should be added to
> > fstab and a daemon-reload is required.
> 
> IIRC mount nowadays stores the full mount option string, including all
> the "userspace-only" options in /run. We could either read those
> directly from there in systemd, or we could make systemd make use of
> libmount to get that information.
 
_netdev is information about device rather than about filesystem.
Would be possible to have this info ("this is iSCSI") in udev db? 

You know, all userpsace mount options suck, it's always fragile to
maintain mount options in userspace (due to namespaces, ...)

> Karel, what are the details there? Would it be OK if we read the files
> in /run directly to augment whatever we got from /proc/self/mountinfo?

I'd like to keep /run/mount/utab as private libmount file. It would be
better to use mnt_table_parse_mtab() libmount function to get parsed
mountinfo + userspace mount options.

IMHO you can implement it as optional feature #ifdef HAVE_LIBMOUNT to
optionally use mnt_table_parse_mtab() from libmount rather than directly
parse /proc/self/mountinfo.

    Karel

-- 
 Karel Zak  <kzak at redhat.com>
 http://karelzak.blogspot.com