mountd segfaults in NFSv4 if -alldirs is present in exports

[George Mamalakis]

On 19/02/2010 20:11, George Mamalakis wrote:
> [root at fbsdclient ~]# mount_newnfs -onfsv4,sec=krb5 
> filesrv.ee.auth.gr:/export /mnt
> nfsv4 err=10016
> mount_newnfs: /mnt, : Input/output error 

I performed some more test on this setup and I can shed a bit more light 
to the issue.

My /etc/export on my server (filesrv.ee.auth.gr) reads:

V4: /  -sec=krb5
/home

If I run:
# mount_newnfs -onfsv4,sec=krb5 filesrv.ee.auth.gr:/home /mnt
as root, without having kinited to some principal, the partition gets 
mounted in /mnt and I can perform operations on it. Once I kinit to some 
user I get the error: nfsv4 err=10016

Then, I read the article on 
http://code.google.com/p/macnfsv4/wiki/FreeBSD8KerberizedNFSSetup a bit 
more thoroughly (with regard to nfsv4), and changed /etc/fstab to read:

V4: /  -sec=krb5
/home -sec=krb5

I restarted nfsd and mountd, switched to a simple user (mamalos), 
kinited as mamalos principal, and typed:

[mamalos at fbsdclient ~]$ mount_newnfs -onfsv4,sec=krb5 
filesrv.ee.auth.gr:/home mnt

where mnt is a directory in mamalos' homefolder owned by that user. Of 
course, one has to run sysctl vfs.usermount=1 in order to allow simple 
users to mount filesystems (as was already suggested by the 
aforementioned article).

This time the mount worked! I ls'd the directory, cd'd to a folder owned 
by mamalos (permissions 700), even touched a file in it. The only 
problem was that the first time I touched a file, it took a few seconds 
for the touch command to complete. After that, all subsequent touch 
commands were executed immediately.

So, for the time being, mounting nfsv4 partitions with sec=krb5 has been 
established, but with a few limitations.

I'll test now what can be done with solaris and linux clients.

Good night everybody (~GMT+2).

-- 
George Mamalakis

IT Officer
Electrical and Computer Engineer (Aristotle Un. of Thessaloniki),
MSc (Imperial College of London)

Department of Electrical and Computer Engineering
Faculty of Engineering
Aristotle University of Thessaloniki

phone number : +30 (2310) 994379