Re: devfs unable to handle permission: 2.4.17-pre[4,5] /

Re: devfs unable to handle permission: 2.4.17-pre[4,5] /

[Thomas Hood]

Some devfs permission problems may have arisen because of the
fact that devfs now notifies devfsd of the creation of
directories.  Many people have devfsd configured to set
permissions to all devices matching a certain regular
expression --- e.g., all devices with "sound" in their
pathname.  The problem is that the "sound" directory itself
matches this regular expression, and so will have its perm
bits set exactly like the device files' perm bits---e.g.,
with the eXamine bit cleared.  The solution is to edit the
devfsd config so that it excludes the directory.  E.g.,
instead of:
    REGISTER sound PERMISSIONS root.audio 0664
(which worked before but won't any more) do:
    REGISTER ^sound/.* PERMISSIONS root.audio 0664
or something similar.

Roman Zippel wrote:
> Option 3:
> Turn a user generated entry into a kernel generated
> one and return 0. Prepopulating devfs was a valid
> option so far, you cannot simply change this during
> a stable kernel release.

As Richard has pointed out, devfs is still marked
"experimental", so it's not unreasonable to make changes
if they are improvements.

--
Thomas Hood

Re: devfs unable to handle permission: 2.4.17-pre[4,5] /

[Richard Gooch]

Thomas Hood writes:
> Some devfs permission problems may have arisen because of the
> fact that devfs now notifies devfsd of the creation of
> directories.  Many people have devfsd configured to set
> permissions to all devices matching a certain regular
> expression --- e.g., all devices with "sound" in their
> pathname.  The problem is that the "sound" directory itself
> matches this regular expression, and so will have its perm
> bits set exactly like the device files' perm bits---e.g.,
> with the eXamine bit cleared.  The solution is to edit the
> devfsd config so that it excludes the directory.  E.g.,
> instead of:
>     REGISTER sound PERMISSIONS root.audio 0664
> (which worked before but won't any more) do:
>     REGISTER ^sound/.* PERMISSIONS root.audio 0664
> or something similar.

Hey! Good spotting! Since the person with the problem didn't send in
his devfsd configuration file, I'm guessing you ran across this
problem yourself?

FYI: recent versions of devfsd now also generate synthetic REGISTER
events for directories. So even with older kernels, people need to fix
their config files.

				Regards,

					Richard....
Permanent: rgooch@atnf.csiro.au
Current:   rgooch@ras.ucalgary.ca

Re: devfs unable to handle permission: 2.4.17-pre[4,5] /

[Roman Zippel]

Hi,

Thomas Hood wrote:

> As Richard has pointed out, devfs is still marked
> "experimental", so it's not unreasonable to make changes
> if they are improvements.

Sure, he can, but that's no excuse if other drivers depend on a certain
behaviuor.

bye, Roman