Re: Failed to Create Symlinks ...

[Matthias Schwarzott <zzam@gentoo.org>]

On Sonntag, 29. November 2009, Kay Sievers wrote:
> On Sat, Nov 28, 2009 at 23:52, Chris Dellin <cdellin@gmail.com> wrote:
> > I'm having some trouble recently with my installation of udev.  I
> > expect it to create symlinks for a few devices, but no symlinks are
> > created.  For example:
> >
> > udev should create a symlink, as per the rule below:
> > $ grep agpgart /etc/udev/rules.d/50-udev.rules
> > KERNEL="agpgart", NAME="misc/%k", SYMLINK+="%k"
> >
> > However, on boot, no symlink exists (although the /dev/misc/agpgart
> > device is properly created).
> >
> > Once booted, the symlink does exist in the udev database:
> > # udevadm info --export-db | grep -A 8 'P: /devices/virtual/misc/agpgart'
> > P: /devices/virtual/misc/agpgart
> > N: misc/agpgart
> > S: agpgart
> > E: UDEV_LOG=3
> > E: DEVPATH=/devices/virtual/misc/agpgart
> > E: MAJOR\x10
> > E: MINOR\x175
> > E: DEVNAME=/dev/misc/agpgart
> > E: DEVLINKS=/dev/agpgart
> >
> > I don't quite know how to interpret the results from udevtest, but the
> > results are here:
> > http://dellin.net/static/temp/udevtest_output.txt
> >
> > A few other notes:
> >  - The system is running a recent copy of Gentoo Linux.
> >  - This started happening when I upgraded my kernel from 2.6.29.5 to
> > 2.6.31.6. - The /dev/video0 symlink has the same problem; it should be
> > linked to /dev/v4l/video0, which is created correctly.
> >
> > Any ideas?
>
> You should not swap kernel node names with symlink names. The primary
> name in /dev should always match the name in /sys. In general, on
> recent kernels, almost all rules with NAME= should be removed and the
> kernel-provided names not be overwritten by userspace config, and only
> symlinks (which do no clash with kernel names) added.
>
I have a similar issue.
the lvm2 package on gentoo installs this udev rule:
KERNEL="device-mapper", SYMLINK+="mapper/control"

Now udev-147 cries about not being able to create the symlink as 
kernel-provided name is already set to "mapper/control".

So is the only possibility to surpress this warning to adjust the rule to 
this?
KERNEL="device-mapper", NAME="mapper/control"

Matthias