procmail is not able to create lock files on NFS share

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Environment

SUSE Linux Enterprise Desktop 10
SUSE Linux Enterprise Server 10

Situation

Procmail is not able to create lock files on an NFS share.

Resolution

The problem is fixed with the latest procmail package (procmail-3.22-56.8).

Additional Information

Root cause

The problem is that since the kernel 2.6.12, the Linux NFS client simulatesflocklocks using fcntl locks on the server. This works fineunlessa client tries to take both an flock and an fcntl lockon the same file at the same time and expects them both to succeed.

This cannot work with the current Linux NFS implementation as theserver will reject the second lock as it sees a conflict. For localfilesystems, the locks are in separate address spaces, and no conflictis seen.

This affects any kernel since 2.6.12 (which includes SLES10) runningwith any program that tries to get both a flock lock and anfcntllock,which procmail does when compiled with LOCKINGTEST=101, but not whencompiled with LOCKINGTEST=100.

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