RHEL 6 NFS client prints "NFS:directory XXXXX contains a readdir loop." due to NFS client issuing the same readdir request twice on a directory whose contents is changing

Issue

• Listing files in a large directory on an NFS mount sometimes produces ELOOP (errno 40) errors in stdout or the kernel log (dmesg) when there are no circular loops present.

• Dovecot generates following messages in /var/log/maillog

Jan 18 13:32:04 host dovecot: imap-login: Login: user=<staff3>, method=PLAIN, rip=1.1.1.1, lip=1.1.1.2, mpid=12283
Jan 18 13:32:22 host dovecot: imap(staff3): Disconnected: Logged out bytes=717/4619
Jan 18 13:32:27 host dovecot: imap-login: Login: user=<testc3>, method=PLAIN, rip=1.1.1.1, lip=1.1.1.2, mpid=12292, TLS
Jan 18 13:32:30 host dovecot: imap(testc3): Error: readdir(/export/mail/testc3/Maildir/new) failed: Too many levels of symbolic links

• And following errors are printed in /var/log/messages

Jan 18 13:32:29 host kernel: NFS: directory Maildir/new contains a readdir loop.  Please contact your server vendor.  Offending cookie: 69645
Jan 18 13:32:30 host kernel: NFS: directory Maildir/new contains a readdir loop.  Please contact your server vendor.  Offending cookie: 69645