fuser -c /somefs fuser -ck /somefs

use -m instead of -c:

fuser -mv /mnt/cdrom/

                     USER        PID ACCESS COMMAND
/mnt/cdrom/          root       2296 ..c..  rpc.rquotad
                     root       2305 ..c..  rpc.mountd

fuser -mk /mnt/cdrom/; fuser -m /mnt/cdrom/

-m     name  specifies  a  file  on  a mounted file system or a block
       device that is mounted. All processes accessing files on  that
       file  system are listed.  If a directory file is specified, it
       is automatically changed to name/. to use any file system that
       might be mounted on that directory.

-v     Verbose  mode.  Processes  are  shown  in a ps-like style. The
       fields PID, USER and COMMAND are similar to ps.  ACCESS  shows
       how  the  process  accesses  the file. If the access is by the
       kernel (e.g. in the case of a mount point, a swap file, etc.),
       kernel is shown instead of the PID.

-k     Kill processes accessing the file. Unless changed with -signal,
       SIGKILL is sent. An fuser process never kills itself, but may
       kill other fuser processes. The effective user ID of the
       process executing fuser is set to its real user ID before
       attempting to kill.