Re: Ubuntu autofs and module-init-tools contacts
Scott James Remnant wrote:
On Wed, 2009-04-15 at 00:31 +0800, Ian Kent wrote:
My initial testing showed that this didn't work in all cases I checked.
The only reason we need anything at all is backward compatibility.
The whole idea here is to get rid of the need to manually load the
autofs module at all.
It's especially important that any auto-loading aliases are *only* done
inside the module. We've had several bugs where auto-loading aliases
were hacked using module-init-tools options files, and they had got out
of date with the kernel, so stopped working.
(Most notably, the floppy module)
A recent audit of all of the module-init-tools options we carried ended
up revealing that the number that were still applicable could actually
be counted with single digits out of literally a hundred different
lines.
So I'd definitely suggest not considering it an option worth taking.
Yes, that was my initial thought.
I know the driver core system very well, so I'd be more than happy to
help you figure out the best way to do things. In general, it's easy
though.
Each subsystem exports a MODALIAS string that matches devices found on
that subsystem, your module can gain wildcard aliases to match through
the use of the MODULE_DEVICE_TABLE macro.
I'm not familiar with MODALIAS, I'll check that.
In addition, there are other magic classes of aliases such as the
{char,block}-major-nnn-yyy style aliases which cause auto-loading on
device node open - these also have kernel macros (one per block) to
support them.
And if all else fails, you can always just use MODULE_ALIAS() to add
your own custom alias - which is exactly equivalent to an alias line for
modprobe (indeed they get *turned into them*).
It appeared to me that it wasn't exactly equivalent.
It seemed that a MODULE_ALIAS() in the module would deal with the
different module name but would fail to map the changed directory name
containing the module whereas an alias in the module-init-tools config
would.
You mention compatibility, one additional compelling reason for not
doing things in config files is actually compatibility. You say that
module names are changing, etc.
If you do things in configuration files, you have a lot of complexity to
support a system which might be running an older kernel version or the
newer one (or indeed, a system which switches between the two).
As you say, the bigger problem is in fact dealing with different kernels
with the same module-init-tools configuration. This maybe a bit of a gotcha!
If you do things in-module, then whichever kernel the user boots *will
still work* because the in-module configuration is used *for that kernel
only*.
The problem I'm seeking to put right started a long long time ago.
We now have two modules in with different names in different directories
that register the same fs name which has to be fixed some time, ;)
Ian
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Re: Ubuntu autofs and module-init-tools contacts
Scott James Remnant wrote: On Wed, 2009-04-08 at 15:24 +0800, Ian Kent wrote: I'm constructing a list of maintainers to include in discussion about a kernel change to the autofs and autofs4 kernel modules that I expect to submit some time in the future. It has the potential to be fairly disruptive and that is the point of trying to stimulate prior discussion and awareness. Your package web pages don't have individual maintainers for the above packages. If you wish to be included in the discussion of this change please advise me of an appropriate contact. I maintain our module-init-tools packages, however we try and limit our packages to only contain the upstream source code and no option overrides (which are better done inside the modules). Thanks for the response. Sure, but at this stage, I'm just trying to construct a list of people that may be affected and Ubuntu didn't list people against packages so I asked. In some cases, such as here this is a heads up in itself. I'll also be contacting the module-init-tools upstream maintainer. The change I'm planning on proposing is to remove the autofs kernel module and rename the autofs4 module to autofs. This has implications for older modprobe code in init scripts as a MODULE_ALIAS() can't do the whole job and an alias will need to be added to the module-init-tools configuration. Of course 2.6.31 (or more probably later) is probably a long way away for many distributions, but raising awareness early can't be a bad thing. Also, knowing who to contact (blame) is a good thing too. Ian -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
Re: Ubuntu autofs and module-init-tools contacts
Scott James Remnant wrote: On Tue, 2009-04-14 at 23:25 +0800, Ian Kent wrote: The change I'm planning on proposing is to remove the autofs kernel module and rename the autofs4 module to autofs. This has implications for older modprobe code in init scripts as a MODULE_ALIAS() can't do the whole job and an alias will need to be added to the module-init-tools configuration. Of course 2.6.31 (or more probably later) is probably a long way away for many distributions, but raising awareness early can't be a bad thing. Also, knowing who to contact (blame) is a good thing too. Why can't MODULE_ALIAS do the whole job? You can do everything with MODULE_ALIAS() that you can do with an alias line in module-init-tools. We have eliminated them all, and are not really looking to put any back ;) I don't know yet. My initial testing showed that this didn't work in all cases I checked. The only reason we need anything at all is backward compatibility. The whole idea here is to get rid of the need to manually load the autofs module at all. Ian -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
Ubuntu autofs and module-init-tools contacts
Hi all, I'm constructing a list of maintainers to include in discussion about a kernel change to the autofs and autofs4 kernel modules that I expect to submit some time in the future. It has the potential to be fairly disruptive and that is the point of trying to stimulate prior discussion and awareness. Your package web pages don't have individual maintainers for the above packages. If you wish to be included in the discussion of this change please advise me of an appropriate contact. Ian Kent -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
