Re: [patch 2/3] Add for_each_host_dev for device only checking

[Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Mon, Aug 20, 2012 at 01:56:27PM +0800, Dave Young wrote:
> On 08/18/2012 01:02 AM, Vivek Goyal wrote:
> 
> > On Fri, Aug 17, 2012 at 08:35:21PM +0800, dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org wrote:
> >> For lvm, multipath, iscsi modules they do not care about the filesystem,
> >> Also there could be devcie in host_devs but it does not get formated.
> >>
> >> For these kind of modules, use for_each_host_dev will be better than use
> >> for_each_host_dev_fs, here add a new function to iterate the host_devs.
> >>
> > 
> > If we decide not to add slave devices in host_devs, then this will not
> > work.
> 
> 
> If we add a line in fstab, then the dev|fs are added to host_fs_types.
> What I'm confusing now is why the for_each_host_dev_fs works without the
> slave devices in host_fs_types.

Because if slave devices have not come up, top level devices in the stack
will not come up. (I think multipath might be exception here).

So I think it should be sufficient to wait for top level block deivce to
come up.

Thanks
Vivek