[systemd-devel] [PATCH] fstab-generator: local-fs.target waits for nofail mounts

[Zbigniew Jędrzejewski-Szmek]

On Tue, Apr 08, 2014 at 06:35:03PM +0800, WANG Chao wrote:
> On 04/08/14 at 02:14am, Zbigniew Jędrzejewski-Szmek wrote:
> > On Mon, Apr 07, 2014 at 03:10:14PM -0400, Vivek Goyal wrote:
> > > On Mon, Apr 07, 2014 at 10:07:20PM +0400, Andrey Borzenkov wrote:
> > > > В Mon, 7 Apr 2014 13:40:17 -0400
> > > > Vivek Goyal <vgoyal at redhat.com> пишет:
> > > > 
> > > > > 
> > > > > Defining a new target which by default waits for all the local fs target
> > > > > sounds interesting. Again, I have the question, what will happen to 
> > > > > local-fs-all.target if some device does not show up and say one of the
> > > > > mounts specified in /etc/fstab fails.
> > It result is different for Requires= and for Wants=. Iff there's a chain
> > of Requires= from the failing unit (.device in this case) to the target unit
> > it will fail. Otherwise, it'll just be delayed. If, as I suggested above local-fs-all.target
> > would have Requires= on the .mount units, then your unit could still have
> > Wants=/After=local-fs-all.target, and it'll be started even if some mounts
> > fail.
> > 
> > > > > What we want is.
> > > > > 
> > > > > - Wait for all devices to show up as specified in /etc/fstab. Run fsck
> > > > >   on devices. Mount devices to mount points specified.
> > > > > 
> > > > > - If everything is successful, things are fine and local-fs-all.target
> > > > >   will be reached.
> > > > > 
> > > > > - If some device does not show up, or if fsck fails or mount fails, still
> > > > >   local-fs-all.target should reach so that kdump module can detect that
> > > > >   failure happened and can take alternative action.
> > Alternatively, you can specify a soft depenendency on local-fs-all.target by
> > using Wants=local-fs-all.target. I think this is preferable, because we want
> > local-fs-all.target to be as similar as possible to local-fs.target, which
> > has Requires= on the mount points.
> 
> Actually, With current implementation, whether "Wants" or "Requires"
> depends on if "nofail" is specified.
It is specified for local-fs.target, which doesn't necessarilly influence
local-fs-all.target, and anyway, here we're talking about the relationship
between local-fs-all.target and some dracut units.

Zbyszek