udev 129 says it supports linux 2.6.19 but prints a warning

udev 129 says it supports linux 2.6.19 but prints a warning

[Mikael Magnusson]

I just updated udev to 129 and got this,
  udev: deprecated sysfs layout (CONFIG_SYSFS_DEPRECATED) is unsupported
However, I have no such option in my kernel config (2.6.19). I assume this
means 2.6.19 will soon not be supported in udev. It would perhaps be nice
if the message said which kernel version would be required after the
deprecation, and how far in the future this will happen?

-- 
Mikael Magnusson

PS I'm not subscribed.

Re: udev 129 says it supports linux 2.6.19 but prints a warning

[Marco d'Itri]

On Oct 03, Mikael Magnusson <mikachu@gmail.com> wrote:

> I just updated udev to 129 and got this,
>   udev: deprecated sysfs layout (CONFIG_SYSFS_DEPRECATED) is unsupported
> However, I have no such option in my kernel config (2.6.19). I assume this
> means 2.6.19 will soon not be supported in udev. It would perhaps be nice
> if the message said which kernel version would be required after the
> deprecation, and how far in the future this will happen?
Agreed. Every time kernel vs. udev requirements change it should be
stated prominently in the release notes, or else it will be hell again
for people like me who need to support real upgrade paths between
distribution releases.

-- 
ciao,
Marco

Re: udev 129 says it supports linux 2.6.19 but prints a warning

[Kay Sievers]

On Fri, Oct 3, 2008 at 10:33 PM, Mikael Magnusson <mikachu@gmail.com> wrote:
> I just updated udev to 129 and got this,
>  udev: deprecated sysfs layout (CONFIG_SYSFS_DEPRECATED) is unsupported
> However, I have no such option in my kernel config (2.6.19). I assume this
> means 2.6.19 will soon not be supported in udev. It would perhaps be nice
> if the message said which kernel version would be required after the
> deprecation, and how far in the future this will happen?

There is no specific plan to remove basic support for the deprecated
sysfs layout. It will likely continue to work fine for basic udev
operations. But people working on current udev versions usually don't
test this anymore, so it might be that there are bugs introduced which
are not handled, hence the "is unsupported" not "it will stop
working".

The deprecated sysfs layout misses information, userspace starts to
rely on, it misses devices, which are not exported by the kernel,
because they could not be inserted into the sysfs device tree without
breaking things. Also some more specialized udev rule features, which
are used, do not work with the old layout. Storage volume handling and
asynchronous media change events in DeviceKit also not work with the
old sysfs layout.

So it's not strictly a udev requirement, it's that system services
will increasingly depend on new features udev offers, which will fail
in in subtle ways with older kernels or the deprecated sysfs layout.

I can change the message to:
   deprecated sysfs layout (kernel too old or CONFIG_SYSFS_DEPRECATED)
is unsupported
or something else, if that sounds better?

Thanks,
Kay

Re: udev 129 says it supports linux 2.6.19 but prints a warning

[Mikael Magnusson]

2008/10/4 Kay Sievers <kay.sievers@vrfy.org>:
> On Fri, Oct 3, 2008 at 10:33 PM, Mikael Magnusson <mikachu@gmail.com> wrote:
>> I just updated udev to 129 and got this,
>>  udev: deprecated sysfs layout (CONFIG_SYSFS_DEPRECATED) is unsupported
>> However, I have no such option in my kernel config (2.6.19). I assume this
>> means 2.6.19 will soon not be supported in udev. It would perhaps be nice
>> if the message said which kernel version would be required after the
>> deprecation, and how far in the future this will happen?
>
> There is no specific plan to remove basic support for the deprecated
> sysfs layout. It will likely continue to work fine for basic udev
> operations. But people working on current udev versions usually don't
> test this anymore, so it might be that there are bugs introduced which
> are not handled, hence the "is unsupported" not "it will stop
> working".

Ah, okay. In the commit message you used the phrasing "Future udev versions
will depend on the current sysfs layout".

> The deprecated sysfs layout misses information, userspace starts to
> rely on, it misses devices, which are not exported by the kernel,
> because they could not be inserted into the sysfs device tree without
> breaking things. Also some more specialized udev rule features, which
> are used, do not work with the old layout. Storage volume handling and
> asynchronous media change events in DeviceKit also not work with the
> old sysfs layout.
>
> So it's not strictly a udev requirement, it's that system services
> will increasingly depend on new features udev offers, which will fail
> in in subtle ways with older kernels or the deprecated sysfs layout.

Okay, I interpreted the "depend on" as "require" in the commit message.

> I can change the message to:
>   deprecated sysfs layout (kernel too old or CONFIG_SYSFS_DEPRECATED)
> is unsupported
> or something else, if that sounds better?

That is probably a little less confusing, thanks :).

-- 
Mikael Magnusson

Re: udev 129 says it supports linux 2.6.19 but prints a warning

[Kay Sievers]

On Sat, Oct 4, 2008 at 10:13 AM, Mikael Magnusson <mikachu@gmail.com> wrote:
> 2008/10/4 Kay Sievers <kay.sievers@vrfy.org>:
>> On Fri, Oct 3, 2008 at 10:33 PM, Mikael Magnusson <mikachu@gmail.com> wrote:
>>> I just updated udev to 129 and got this,
>>>  udev: deprecated sysfs layout (CONFIG_SYSFS_DEPRECATED) is unsupported
>>> However, I have no such option in my kernel config (2.6.19). I assume this
>>> means 2.6.19 will soon not be supported in udev. It would perhaps be nice
>>> if the message said which kernel version would be required after the
>>> deprecation, and how far in the future this will happen?
>>
>> There is no specific plan to remove basic support for the deprecated
>> sysfs layout. It will likely continue to work fine for basic udev
>> operations. But people working on current udev versions usually don't
>> test this anymore, so it might be that there are bugs introduced which
>> are not handled, hence the "is unsupported" not "it will stop
>> working".
>
> Ah, okay. In the commit message you used the phrasing "Future udev versions
> will depend on the current sysfs layout".

Yeah, we kind of already "depend" on it. It just depends on what
features you are looking at. We can not know which udev features other
services use, they usually just depend on a specific udev version, not
a kernel/sysfs version, but udev can not offer some features on older
kernels.

>> The deprecated sysfs layout misses information, userspace starts to
>> rely on, it misses devices, which are not exported by the kernel,
>> because they could not be inserted into the sysfs device tree without
>> breaking things. Also some more specialized udev rule features, which
>> are used, do not work with the old layout. Storage volume handling and
>> asynchronous media change events in DeviceKit also not work with the
>> old sysfs layout.
>>
>> So it's not strictly a udev requirement, it's that system services
>> will increasingly depend on new features udev offers, which will fail
>> in in subtle ways with older kernels or the deprecated sysfs layout.
>
> Okay, I interpreted the "depend on" as "require" in the commit message.

Yeah, it's hard to tell. It will not stop creating device nodes, but
the rest we can not be sure about. :)

>> I can change the message to:
>>   deprecated sysfs layout (kernel too old or CONFIG_SYSFS_DEPRECATED)
>> is unsupported
>> or something else, if that sounds better?
>
> That is probably a little less confusing, thanks :).

I'll do this.

Thanks,
Kay