Dunno. I've actually gone back to v3 everywhere I use nfs because v4 just seems too hard to make work properly with Linux. -Adam

Trevor Cordes trevor@tecnopolis.ca wrote:

A recent update (kernel, or something else) seems to have messed up file locking over NFSv4 on my system (yes, v4 allows for locking).

I use locking in perl scripts over NFS and it's always worked until now. I checked and lockd is running on the server still.

A test case is at the bottom of this email. The problem hits on line 13 where the open-for-write happens. It dies with "Input/output error".

The client's /v/l/messages says: [156474.509107] nfs4_reclaim_open_state: Lock reclaim failed!

If I run this on a local file, not over NFS, it works fine.

I'm using the lock functions as the sample code in the perl docs instructs. My goal is to lock a file, read it, do things, and write it out, all atomically. Mostly I want to protect against another instance of the same program doing the same thing at the same time and screwing up the file.

My NFS server is a an older linux (Fedora 14) than the client (Fedora 16), but the NFSv4 spec hasn't really changed in that span.

#!/usr/bin/perl -w # use Fcntl ':flock';

$file='/data/Tmp/locktest';

open(LOCK,$file) or die; flock(LOCK,LOCK_EX);

open(IN,$file) or die; # read from file close(IN);

open(ORI,">$file") or die $!; # dies here!!!!!!!!!!!!1 # write to file close(ORI);

flock(LOCK,LOCK_UN); _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable