When specifying a CIFS share in a map file, specify -fstype=cifs and precede the share location with a colon (:).

 

Example:

 

mntpoint -fstype=cifs ://example.com/shrname

 

Example: Mount read-write, specifying a user and group to own the files:

 

mntpoint -fstype=cifs,rw,uid=myuserid,gid=mygrpid ://example.com/shrname

 

Example: Mount read-write, specifying a username and password to use to connect to the share:

 

mntpoint -fstype=cifs,rw,username=myuser,password=mypass ://example.com/shrname

When specifying a CIFS share in a map file, specify -fstype=cifs and precede the share location with a colon (:).

Example:

mntpoint -fstype=cifs ://example.com/shrname

Example: Mount read-write, specifying a user and group to own the files:

mntpoint -fstype=cifs,rw,uid=myuserid,gid=mygrpid ://example.com/shrname

Example: Mount read-write, specifying a username and password to use to connect to the share:

mntpoint -fstype=cifs,rw,username=myuser,password=mypass ://example.com/shrname

EDIT:

What I'm asking for is an easy way to do this without having to manually invoke the command at a prompt, and without having to store (or fudge) the credentials in a file.

Linux can mount/unmount various filesystem via mount.* and umount.* executables. This credentials=/etc/credentials.txt option in the linked example is in fact an option to mount.cifs. I think if you use something like

mount -t foo …

or in autofs configuration:

mntpoint -fstype=foo …

it will try to find and run mount.foo, passing all other options to it.

So you should create mount.mycifs as a wrapper over mount.cifs. It should prompt you for your credentials somehow (straightforward xterm -e … maybe, use read or dialog or something else; but read this please), add -o username=…,password=… or -o credentials=… to the rest of options and pass them to mount.cifs (or mount -t cifs) which does the actual mounting.

If you have umount.cifs then make umount.mycifs a symlink to it.

Then use -fstype=mycifs in your map file without any options related to credentials.

The following /sbin/mount.mycifs is a quick and dirty proof of concept. Understand what it does before you run it in your OS because it will be run as root, I'm a random guy on the Internet and you shouldn't trust me.

#!/bin/bash

tmpf="`mktemp`"
DISPLAY=:0 XAUTHORITY=/home/ola/.Xauthority xterm -e /bin/bash -c '\
read -p "user:" u; \
read -sp "password:" p; \
printf "username=%s\npassword=%s" "$u" "$p" > "$0"; \
' "$tmpf"

mount -t cifs "$@" -o credentials="$tmpf"
rm "$tmpf"

It should be owned by root:root or whatever is proper for mount.* in your OS. Don't forget to make it executable (sudo chmod a+x /sbin/mount.mycifs), it won't work otherwise. Notice there's a nasty hack with DISPLAY and XAUTHORITY that allows the autofs daemon to display xterm window on your(?) screen but in general it shouldn't do it. The hack is only for the daemon, mount -t mycifs … should be able to display xterm without the hack if invoked from within your desktop environment.

To make it less dirty you should write yet another program or script and run it with your local user's limited permissions before you access a directory where your CIFS would be automounted. This script should wait for a signal from mount.mycifs, prompt you for the credentials (it can display windows etc. without nasty hacks) and pass them to mount.mycifs which shouldn't display any windows nor prompts on its own.