[gentoo-dev] Re: /usr vs. initramfs redux

[Steven J Long]

Sven Vermeulen wrote:

> On Fri, Aug 05, 2011 at 07:42:29PM -0500, William Hubbs wrote:
>> On Fri, Aug 05, 2011 at 10:06:48PM +0200, Sven Vermeulen wrote:
>> > That said, I'm a bit hesitant to describing that we "recommend" it
>> > regardless of the situation. What is wrong with describing when? At
>> > least inform our users that the udev rules have evolved to more than
>> > just "detect and mknod" scripts and that they are now relying on files
>> > and binaries available in other locations, like /usr and /var.

That seems reasonable.
>>
>> It looks like the situation where we will have to have one is if /usr
>> and /var are not on the same file system as /, because of how udev has
>> evolved.
>
> This isn't always true. I have /usr and /var on separate logical volumes
> (and as such, separate file systems) yet I don't use DEVTMPFS nor an
> initrd/initramfs, so I'm sure that the answer is a bit more specific.
>
I have the same setup and no issues either. I think the problem is for other 
devices, eg someone mentioned having a bluetooth adapter in their laptop 
which gets picked up at boot by udev, but needs helpers in /usr.

According to https://bugs.gentoo.org/show_bug.cgi?id=364235#c1 udev marks 
(or marked) failing probers as missing devices, not failed, so udev-
postmount doesn't pick on them as needing to be rescanned.

I'm not sure if that bug's been fixed or not; the call to util_run_program 
is no longer in that function at: 
http://git.kernel.org/?p=linux/hotplug/udev.git;a=blob_plain;f=udev/udev-
rules.c;hb=HEAD
..but it might well have the same logical error for all I know.

I don't get why we can't allow udev to need localmount, as described in the 
bug, with CONFIG_DEVTMPFS creating nodes needed to mount /usr /var etc, 
especially as that setting is now being recommended by upstream. (And ofc we 
don't have to use it if it's not needed.)

Regards,
igli.
-- 
#friendly-coders -- We're friendly, but we're not /that/ friendly ;-)