Why mount cifs can create multiple mounts in 1 mount point, how to get rid of it?

Question

linux

Debian has this problem. Let's say I write the mount string cifs balls in /etc/fstab.
Next, I run mount -a, everything is mounted.
I run mount -a again.
After that, I look at my mounts with the mount command:
//Server/xxx on /home/xxx/xxx type cifs
//Server/xxx on /home/xxx/xxx type cifs
I see 2 absolutely identical mounts.
Found an article .
But this is how we use not fstab, but pam_mount, with several user logins on the server, many such mounts are formed that look exactly the same in mtab. Has anyone solved a similar problem?
I tried to solve the issue using pam, I think that pam_tally.so will count inputs, and if this is not the first input, it will skip pam_mount, but maybe I made a mistake in the syntax:

spoiler

auth optional [success=1 default=ignore] pam_tally.so deny=1 onerr=succeed no_lock_time no_reset
auth optional pam_mount.so

Answer 1

Mount does not prevent anything from being mounted on top of the mounted one.
Access will be to what was mounted last.