[PATCH] Make CONFIG_FHANDLE default y

[PATCH] Make CONFIG_FHANDLE default y

[Andi Kleen]

From: Andi Kleen <ak@linux.intel.com>

Newer Fedora and OpenSUSE didn't boot with my standard configuration.
It took me some time to figure out why, in fact I had to write a script
to try different config options systematically.

The problem is that something in dracut depends on CONFIG_FHANDLE,
which adds open by file handle syscalls.

While it is set in defconfigs it is very easy to miss when updating
older configs because it is not default y.

Make it default y and also depend on EXPERT, as dracut use is likely
wide spread.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 init/Kconfig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/init/Kconfig b/init/Kconfig
index e0d26162432e..0dfd09d54c65 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -272,8 +272,9 @@ config CROSS_MEMORY_ATTACH
 	  See the man page for more details.
 
 config FHANDLE
-	bool "open by fhandle syscalls"
+	bool "open by fhandle syscalls" if EXPERT
 	select EXPORTFS
+	default y
 	help
 	  If you say Y here, a user level program will be able to map
 	  file names to handle and then later use the handle for
-- 
2.5.5

Re: [PATCH] Make CONFIG_FHANDLE default y

[Richard Weinberger]

On Thu, Mar 31, 2016 at 5:24 PM, Andi Kleen <andi@firstfloor.org> wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> Newer Fedora and OpenSUSE didn't boot with my standard configuration.
> It took me some time to figure out why, in fact I had to write a script
> to try different config options systematically.
>
> The problem is that something in dracut depends on CONFIG_FHANDLE,
> which adds open by file handle syscalls.

s/something/systemd. :-)

-- 
Thanks,
//richard

Re: [PATCH] Make CONFIG_FHANDLE default y

[Andi Kleen]

On Thu, Mar 31, 2016 at 05:52:52PM +0200, Richard Weinberger wrote:
> On Thu, Mar 31, 2016 at 5:24 PM, Andi Kleen <andi@firstfloor.org> wrote:
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > Newer Fedora and OpenSUSE didn't boot with my standard configuration.
> > It took me some time to figure out why, in fact I had to write a script
> > to try different config options systematically.
> >
> > The problem is that something in dracut depends on CONFIG_FHANDLE,
> > which adds open by file handle syscalls.
> 
> s/something/systemd. :-)

Makes sense thanks. It should probably give a better error message
like it gives for missing cgroups
(right now just your root file system is missing)

But right now we should avoid others having the same pain
and make the option default.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

Re: [PATCH] Make CONFIG_FHANDLE default y

[Richard Weinberger]

Am 31.03.2016 um 20:42 schrieb Andi Kleen:
> On Thu, Mar 31, 2016 at 05:52:52PM +0200, Richard Weinberger wrote:
>> On Thu, Mar 31, 2016 at 5:24 PM, Andi Kleen <andi@firstfloor.org> wrote:
>>> From: Andi Kleen <ak@linux.intel.com>
>>>
>>> Newer Fedora and OpenSUSE didn't boot with my standard configuration.
>>> It took me some time to figure out why, in fact I had to write a script
>>> to try different config options systematically.
>>>
>>> The problem is that something in dracut depends on CONFIG_FHANDLE,
>>> which adds open by file handle syscalls.
>>
>> s/something/systemd. :-)
> 
> Makes sense thanks. It should probably give a better error message
> like it gives for missing cgroups
> (right now just your root file system is missing)

That's an improvement, a few release ago it segfaulted in that case.

> But right now we should avoid others having the same pain
> and make the option default.

FHANDLE is part of x86's defconfig.

Please see https://github.com/systemd/systemd/blob/master/README#L37 for a list
of needed kernel options.

Thanks,
//richard