2.6.21.3: NFS: Buggy server - nlink == 0!

2.6.21.3: NFS: Buggy server - nlink == 0!

[Ravikiran G Thirumalai]

While running a dbench stress test on  a nfs mounted file system, I notice
the subject error message on the client machine.  The client machine is a 48
core box with NUMA characteristics and 1024 dbench processes running
continuously in a loop, while another memory hog application runs in parallel.
The client is on 2.6.21.3.  The server is booted up with 2.6.21.3 as well.
Attached is the server configuration.  Same test on a 2.6.16 client does not
spew out these messages.  Is this really the server issue, or is the NFS
client to be blamed here?

fstab on the client goes as:
vus2:/mnt/sda5          /nfstest                nfs  udp,wsize=32768,rsize=32768 0 0

/etc/exports on the server looks like:
/mnt/sda5 *(rw,no_root_squash,sync)

I will be happy to post full config/dmesg if required.

The client side NFS config goes as:
#
# Network File Systems
#
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
# CONFIG_NFS_V3_ACL is not set
# CONFIG_NFS_V4 is not set
CONFIG_NFS_DIRECTIO=y
CONFIG_NFSD=y
CONFIG_NFSD_V3=y
# CONFIG_NFSD_V3_ACL is not set
# CONFIG_NFSD_V4 is not set
CONFIG_NFSD_TCP=y
CONFIG_LOCKD=y
CONFIG_LOCKD_V4=y
CONFIG_EXPORTFS=y
CONFIG_NFS_COMMON=y
CONFIG_SUNRPC=y
# CONFIG_RPCSEC_GSS_KRB5 is not set
# CONFIG_RPCSEC_GSS_SPKM3 is not set

The server side NFS config goes as:

#
# Network File Systems
#
CONFIG_NFS_FS=m
CONFIG_NFS_V3=y
CONFIG_NFS_V3_ACL=y
# CONFIG_NFS_V4 is not set
CONFIG_NFS_DIRECTIO=y
CONFIG_NFSD=m
CONFIG_NFSD_V2_ACL=y
CONFIG_NFSD_V3=y
CONFIG_NFSD_V3_ACL=y
CONFIG_NFSD_V4=y
CONFIG_NFSD_TCP=y
CONFIG_LOCKD=m
CONFIG_LOCKD_V4=y
CONFIG_EXPORTFS=m
CONFIG_NFS_ACL_SUPPORT=m
CONFIG_NFS_COMMON=y
CONFIG_SUNRPC=m

Thanks,
Kiran

Re: 2.6.21.3: NFS: Buggy server - nlink == 0!

[Trond Myklebust]

The server is returning a deleted file to the client as the result of a
lookup() call. I'd call that a server bug.

Trond


On Wed, 2007-06-06 at 01:13 -0700, Ravikiran G Thirumalai wrote:
> While running a dbench stress test on  a nfs mounted file system, I notice
> the subject error message on the client machine.  The client machine is a 48
> core box with NUMA characteristics and 1024 dbench processes running
> continuously in a loop, while another memory hog application runs in parallel.
> The client is on 2.6.21.3.  The server is booted up with 2.6.21.3 as well.
> Attached is the server configuration.  Same test on a 2.6.16 client does not
> spew out these messages.  Is this really the server issue, or is the NFS
> client to be blamed here?
> 
> fstab on the client goes as:
> vus2:/mnt/sda5          /nfstest                nfs  udp,wsize=32768,rsize=32768 0 0
> 
> /etc/exports on the server looks like:
> /mnt/sda5 *(rw,no_root_squash,sync)
> 
> I will be happy to post full config/dmesg if required.
> 
> The client side NFS config goes as:
> #
> # Network File Systems
> #
> CONFIG_NFS_FS=y
> CONFIG_NFS_V3=y
> # CONFIG_NFS_V3_ACL is not set
> # CONFIG_NFS_V4 is not set
> CONFIG_NFS_DIRECTIO=y
> CONFIG_NFSD=y
> CONFIG_NFSD_V3=y
> # CONFIG_NFSD_V3_ACL is not set
> # CONFIG_NFSD_V4 is not set
> CONFIG_NFSD_TCP=y
> CONFIG_LOCKD=y
> CONFIG_LOCKD_V4=y
> CONFIG_EXPORTFS=y
> CONFIG_NFS_COMMON=y
> CONFIG_SUNRPC=y
> # CONFIG_RPCSEC_GSS_KRB5 is not set
> # CONFIG_RPCSEC_GSS_SPKM3 is not set
> 
> The server side NFS config goes as:
> 
> #
> # Network File Systems
> #
> CONFIG_NFS_FS=m
> CONFIG_NFS_V3=y
> CONFIG_NFS_V3_ACL=y
> # CONFIG_NFS_V4 is not set
> CONFIG_NFS_DIRECTIO=y
> CONFIG_NFSD=m
> CONFIG_NFSD_V2_ACL=y
> CONFIG_NFSD_V3=y
> CONFIG_NFSD_V3_ACL=y
> CONFIG_NFSD_V4=y
> CONFIG_NFSD_TCP=y
> CONFIG_LOCKD=m
> CONFIG_LOCKD_V4=y
> CONFIG_EXPORTFS=m
> CONFIG_NFS_ACL_SUPPORT=m
> CONFIG_NFS_COMMON=y
> CONFIG_SUNRPC=m
> 
> Thanks,
> Kiran
> -
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