Kernel message when no support for NFSv4 compiled into it

[Thierry Moreau <thierry.moreau@connotech.com>]

Dear nfs developers,

I just SOLVED my operational problem. Maybe the symptom vs solution is 
of interest to you.

Kernel 3.5.4, nfs-utils 1.2.7

     ./configure --prefix=/usr \
                 --mandir=/usr/man \
                 --sysconfdir=/etc \
                 --with-statedir=/var/lib/nfs \
                 --disable-gss \
                 --with-tcp-wrappers \
                 --enable-libmount-mount

starting script:

         /sbin/rpcbind -h 192.168.1.17
         /bin/mount -t nfsd nfsd $NFSD
         /bin/mount -t rpc_pipefs rpc_pipefs $PIPEFS
         /usr/sbin/rpc.idmapd
         /usr/sbin/exportfs -a
         /usr/sbin/rpc.mountd
         /usr/sbin/rpc.statd --no-notify
         /usr/sbin/rpc.nfsd --syslog 8A <==== this is where the kernel 
would report an error
         /usr/sbin/sm-notify

kernel configuration changes

bash-4.2# diff config_02 config_04
d2437c2447,2448
< # CONFIG_NFSD_V4 is not set
---
 > CONFIG_NFSD_V4=y
 > # CONFIG_NFSD_FAULT_INJECTION is not set
2441a2453
 > CONFIG_SUNRPC_GSS=m
d2622c2639,2641
< # CONFIG_KEYS is not set
---
 > CONFIG_KEYS=y
 > CONFIG_ENCRYPTED_KEYS=m
 > CONFIG_KEYS_DEBUG_PROC_KEYS=y
2625a2645
 > # CONFIG_DEFAULT_SECURITY_SELINUX is not set
2646a2667
 > CONFIG_CRYPTO_RNG=m
2700c2721
< # CONFIG_CRYPTO_SHA256 is not set
---
 > CONFIG_CRYPTO_SHA256=m

With config_02 kernel, nfsd would not work (no big deal so far). But it 
did work fine prior to a controlled system reboot where prior live 
system had experienced extensive playing with nfsd installation (not 
much help for you since I can not tell what made it work).

What may be of interest to you is that with config_02 kernel, it is the 
*kernel* that reports an error message on the system console, right upon 
nfsd startup. It is only by (painful) trial and error that the cause for 
the kernel message was found. The kernel message message occurred even 
with the --disable-nfsv4/nfsv41 configure options.

I don't have the exact kernel messages at hand (circa memory mapping 
then circa NULL pointer dereferencing during the trial-and-error chase).

I might be able to provide additional information if you ask politely. 
Maybe I owe it to this great free software contribution anyway.

Thanks.

P.S. I saw no archive of this mailing list, thus I e-mail without much 
background info.

-- 
- Thierry Moreau

CONNOTECH Experts-conseils inc.
9130 Place de Montgolfier
Montreal, QC, Canada H2M 2A1

Tel. +1-514-385-5691