Kernel module package naming

Kernel module package naming

[ola.redell]

From: Ola Redell <ola.redell@retotech.se>

Hi,

I have been working on a problem with safe kernel and kernel-module upgrade 
on a system using .deb packages and apt-get as package manager.

My problem has been that I need to be able to fall back to an earlier kernel
if a newly installed kernel fails to boot for some reason. The basic support
for this is handled in U-boot, but my problem has been with the upgrade of kernel
modules. Today, the same kernel module for different kernel versions has the
same name for both kernels and differ only in its package version. This
makes package managers remove the old kernel module when the newer one is
installed. As a result a safe fall back to the older kernel, whith its (old) 
modules is very difficult.

I have a solution that works for me by changing the kernel-module-split.bbclass 
to add the KERNEL_VERSION string to the kernel module package name. I assume 
this could be useful also in the general case. I am not a package management 
expert though, so let me know what you think.

/Ola

Ola Redell (1):
  Append KERNEL_VERSION string to kernel module package names

 meta/classes/kernel-module-split.bbclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
1.9.1

[PATCH] Append KERNEL_VERSION string to kernel module package names

[ola.redell]

From: Ola Redell <ola.redell@retotech.se>

The KERNEL_VERSION string is added to kernel module package names in order to
make the kernel modules for different kernel versions distinct packages instead
of different versions of the same package. With this change, when a new kernel
is installed together with its kernel modules (e.g. by upgrade of the packages
kernel and kernel-modules) using some package manager such as apt-get or rpm,
the kernel modules for the older kernel will not be removed. This enables a
fall back to the older kernel if the new one fails.

Signed-off-by: Ola Redell <ola.redell@retotech.se>
---
 meta/classes/kernel-module-split.bbclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/classes/kernel-module-split.bbclass b/meta/classes/kernel-module-split.bbclass
index efe1b42..8365448 100644
--- a/meta/classes/kernel-module-split.bbclass
+++ b/meta/classes/kernel-module-split.bbclass
@@ -122,7 +122,7 @@ python split_kernel_module_packages () {
     module_regex = '^(.*)\.k?o$'
 
     module_pattern_prefix = d.getVar('KERNEL_MODULE_PACKAGE_PREFIX')
-    module_pattern = module_pattern_prefix + 'kernel-module-%s'
+    module_pattern = 'kernel-module-%s-' + d.getVar("KERNEL_VERSION", True)
 
     postinst = d.getVar('pkg_postinst_modules')
     postrm = d.getVar('pkg_postrm_modules')
-- 
1.9.1

Re: [PATCH] Append KERNEL_VERSION string to kernel module package names

[Mats Karrman]

Hi,

On 01/03/2017 02:42 PM, ola.redell@gmail.com wrote:
> From: Ola Redell <ola.redell@retotech.se>
>
> The KERNEL_VERSION string is added to kernel module package names in order to
> make the kernel modules for different kernel versions distinct packages instead
> of different versions of the same package. With this change, when a new kernel
> is installed together with its kernel modules (e.g. by upgrade of the packages
> kernel and kernel-modules) using some package manager such as apt-get or rpm,
> the kernel modules for the older kernel will not be removed. This enables a
> fall back to the older kernel if the new one fails.
>
> Signed-off-by: Ola Redell <ola.redell@retotech.se>
> ---
>   meta/classes/kernel-module-split.bbclass | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/meta/classes/kernel-module-split.bbclass b/meta/classes/kernel-module-split.bbclass
> index efe1b42..8365448 100644
> --- a/meta/classes/kernel-module-split.bbclass
> +++ b/meta/classes/kernel-module-split.bbclass
> @@ -122,7 +122,7 @@ python split_kernel_module_packages () {
>       module_regex = '^(.*)\.k?o$'
>   
>       module_pattern_prefix = d.getVar('KERNEL_MODULE_PACKAGE_PREFIX')
> -    module_pattern = module_pattern_prefix + 'kernel-module-%s'
> +    module_pattern = 'kernel-module-%s-' + d.getVar("KERNEL_VERSION", True)
Why did you drop 'module_pattern_prefix'?
>   
>       postinst = d.getVar('pkg_postinst_modules')
>       postrm = d.getVar('pkg_postrm_modules')

Re: [PATCH] Append KERNEL_VERSION string to kernel module package names

[Ola Redell]

Thanks, that was a mistake. I did this change in Jethro originally where 
the prefix does not appear. I will prepare a v2.

Ola


On 2017-01-03 14:56, Mats Karrman wrote:
> -    module_pattern = module_pattern_prefix + 'kernel-module-%s'
>> +    module_pattern = 'kernel-module-%s-' + 
>> d.getVar("KERNEL_VERSION", True)
> Why did you drop 'module_pattern_prefix'?
>>         postinst = d.getVar('pkg_postinst_modules')
>>       postrm = d.getVar('pkg_postrm_modules')
>