[Lustre-discuss] Lustre, NFS and mds_getattr_lock operation

[Andreas Dilger]

On 2010-05-06, at 11:57, Frederik Ferner wrote:
> On our Lustre system we are seeing the following error fairly regularly, 
> so far we have not had complaints from users and have not noticed any 
> negative effects, but it would still be nice to understand the errors 
> better. The systems reporting these errors are NFS exporters for 
> subtrees of the Lustre file system.
> 
> One the Lustre client/NFS server:
> 
> May  6 14:23:09 i16-storage1 kernel: LustreError: 11-0: an error 
> occurred while communicating with 172.23.68.8 at tcp. The mds_getattr_lock 
> operation failed with -13

-13 is -EACCESS (per /usr/include/asm-generic/errno-base.h) or equivalent

That just means that someone tried to access a file they don't have permission to access.  As to why this is being printed on the console is a bit of a mystery, since I haven't seen anything similar.  I wonder if NFS is going down some obscure code path that is returning the error to the RPC handler instead of stashing this "normal" error code inside the reply.

In any case it is harmless and expected (sigh).  I'd hope it would have been removed in newer versions, but I don't know at all.

> Does anyone know if we should worry about those messages or if we can 
> safely ignore them? Or should we assume that some of our users might 
> have a problem accessing data that they have just not reported? Even 
> though I find that unlikely.

Cheers, Andreas
--
Andreas Dilger
Lustre Technical Lead
Oracle Corporation Canada Inc.