I noticed that libsmb returns an error when mount.smbfs (smbmnt/
smbmount) is run setuid. Is this new (I don't remember this last year)?
This probably means that smbfs can not do user mounts anymore which may
be ok, but fortunately this does not affect the linux cifs vfs (since
that does not link to any Samba libraries). I have been experimenting
with returning the mounting user in the /proc/mounts line as "user=xx"
where xx is the uid (number), the cifs lines in that pseudofile already
had the username passed on the mount but that is slightly different.
Interestingly mount puts the - name - of the user corresponding to the
uid of the process (not the uid number itself) in /etc/mtab when
mounting local filesystems with user (setuid user mounts).