I've configured pam_mount.so to automagically mount a cifs share when users login; the problem is if a user logs into multiple times simultaneously, the mount command is repeated multiple times.

This so far isn't a problem but it's messy when you look at the output of a mount command.

# mount
/dev/sda1 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
none on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
none on /dev type devtmpfs (rw,mode=0755)
none on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
none on /dev/shm type tmpfs (rw,nosuid,nodev)
none on /var/run type tmpfs (rw,nosuid,mode=0755)
none on /var/lock type tmpfs (rw,noexec,nosuid,nodev)
none on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
//srv1/UserShares/jrisk on /home/jrisk type cifs (rw,mand)
//srv1/UserShares/jrisk on /home/jrisk type cifs (rw,mand)
//srv1/UserShares/jrisk on /home/jrisk type cifs (rw,mand)

I'm assuming I need to fiddle with either the pam.d/common-auth file or pam_mount.conf.xml to accomplish this.

How can I instruct pam_mount.so to avoid duplicate mountings?