[Buildroot] Buildroot root fs over NFS bug

[Buildroot] Buildroot root fs over NFS bug

[Jigar SOLANKI]

Hi all,

I'm trying to build a full Linux environment on a Virtex4 FPGA board.
I'm actually using a sparc's clone (LEON).
I've successfully built and run the system using grmon
grmon> load image.ram
grmon> run

But when it comes to mount the root filesystem over NFS, i get the
following error :

...
IP-Config: Complete:
     device=eth0, addr=10.10.10.1, mask=255.255.255.0, gw=10.10.10.254,
     host=houat, domain=, nis-domain=(none),
     bootserver=10.10.10.254, rootserver=10.10.10.254, rootpath=
Freeing unused kernel memory: 5060k freed
Initializing random number generator... done.
Starting network...
ip: RTNETLINK answers: File exists
Starting NFS statd: touch: /var/lock/subsys/nfslock: No such file or
directory
done
Starting NFS services: *** invalid open64 call: O_CREAT without mode
***: /usr/sbin/exportfs terminated
======= Backtrace: =========
/lib/libc.so.6(__open64_2+0x28)[0x50133790]
/usr/sbin/exportfs[0x15ca8]
/usr/sbin/exportfs[0x13d90]
/usr/sbin/exportfs[0x11f3c]
/lib/libc.so.6(__libc_start_main+0x10c)[0x50079674]
/usr/sbin/exportfs[0x11154]
======= Memory map: ========
00010000-00019000 r-xp 000000
Welcome to Buildroot
buildroot login:


I have checked my NFS server : it works fine, i can mount after boot
without any problems :
mount -o nolock -t nfs ip:path mountpoint


Any ideas please ?
Thanks a lot for your help

-- 
Jigar SOLANKI


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[Buildroot] Buildroot root fs over NFS bug

[Thomas Petazzoni]

Hello,

Le Tue, 28 Jun 2011 14:27:12 +0200,
Jigar SOLANKI <jigar.solanki@labri.fr> a ?crit :

> I'm trying to build a full Linux environment on a Virtex4 FPGA board.
> I'm actually using a sparc's clone (LEON).
> I've successfully built and run the system using grmon
> grmon> load image.ram
> grmon> run
> 
> But when it comes to mount the root filesystem over NFS, i get the
> following error :

According to the following log, you are not mounting your root
filesystem over NFS.

> ...
> IP-Config: Complete:
>      device=eth0, addr=10.10.10.1, mask=255.255.255.0,
> gw=10.10.10.254, host=houat, domain=, nis-domain=(none),
>      bootserver=10.10.10.254, rootserver=10.10.10.254, rootpath=
> Freeing unused kernel memory: 5060k freed

This is the last line from the kernel.

> Initializing random number generator... done.

This is the first line from the userspace initialization scripts. So I
guess your root filesystem is in an initramfs.

> Starting network...
> ip: RTNETLINK answers: File exists
> Starting NFS statd: touch: /var/lock/subsys/nfslock: No such file or
> directory

presumably the nfs-utils init script forgets to create this subsys
directory.

> done
> Starting NFS services: *** invalid open64 call: O_CREAT without mode
> ***: /usr/sbin/exportfs terminated
> ======= Backtrace: =========
> /lib/libc.so.6(__open64_2+0x28)[0x50133790]
> /usr/sbin/exportfs[0x15ca8]
> /usr/sbin/exportfs[0x13d90]
> /usr/sbin/exportfs[0x11f3c]
> /lib/libc.so.6(__libc_start_main+0x10c)[0x50079674]
> /usr/sbin/exportfs[0x11154]
> ======= Memory map: ========
> 00010000-00019000 r-xp 000000

Looks like a bug in exportfs.

But if your goal is to mount a root filesystem over NFS, then the
nfs-utils package is useless. The kernel contains all the necessary
bits to mount a NFS filesystem as the root filesystem.

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] Buildroot root fs over NFS bug

[Thomas Petazzoni]

Hello,

Please don't reply to me directly, but to the Buildroot list instead.

Le Wed, 29 Jun 2011 15:15:14 +0200,
Jigar SOLANKI <jigar.solanki@labri.fr> a ?crit :

> Thanks a lot for the reply.
> You were absolutely right, my bad, I wasnt mounting my root filesystem
> over NFS, it was just an initramfs.
> 
> I deactivated the initramfs support in the kernel config and it mounts
> just fine.
> 
> My question, just to be sure, is : why the kernel wasnt  mounting it
> before, even if it had everything in his command line (and even if the
> initramfs support was activated ?) It should have mounted it, right ?

If you have an initramfs, then the kernel uncompresses it at boot time,
and executes the /init script/application in this initramfs. And that's
all the kernel does when an initramfs is present: it's the job of the
initramfs initialization procedure to mount the real root filesystem
and switch to it.

So if you have an initramfs, it's normal not to see the typical:

  VFS: Mounted root (nfs filesystem) on device 0:14.

message in your boot log.

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com