Red Hat Bugzilla – Bug 55981
NFS mailboxes won't unlock in imapd
Last modified: 2007-04-18 12:38:11 EDT
From Bugzilla Helper:
User-Agent: Mozilla/4.77 [en] (X11; U; Linux 2.4.9-6 i686)
Description of problem:
After imapd reads an NFS-mounted mailbox, it hangs trying to release the
fcntl() lock on it. An strace -p shows data being read from the mailbox
and then the fcntl() call never returns. A kill -9 is needed to terminate
the daemon, which then leaves .lock files behind. The process is listed as
sleeping in ps. At least it's not a 'D' wait!
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Mount IMAP mailbox over NFS.
2. Try to read messages.
Actual Results: IMAP server hangs trying to unlock mailbox. Client
eventually times out but server processes hang around until killed -9.
Expected Results: The lock should have been released.
NFS mounted filesystems here are ReiserFS, not sure what happens with
ext2/3. Chris Mason of SuSE thinks it's not ReiserFS-specific.
OK, I've reproduced this with the standalone flock.c from the IMAP source. I've
also reproduced it with an NFS mount of an ext2 filesystem. Kernel 2.4.9-6
We've released an update for this several days ago; 2.4.9-12 has, appart from
the security fixes, also the NFS locking bug fixed. I recommend giving that a try.