Quickly create a size-limited directory

limkdir.sh

#!/bin/bash

path=$1
sizelimit=$2

echo "Creating directory at $path, limited to $sizelimit MiB..."

mkdir "$path" 2>/dev/null || { exit; }
mkdir "/tmp/quotaimg" 2>/dev/null || { exit; }
dd if=/dev/zero of=/tmp/quotaimg/tmp.ext3 bs=1M count=$sizelimit
/sbin/mkfs -t ext3 -q /tmp/quotaimg/tmp.ext3 -F
sudo mount -o loop,rw,usrquota,grpquota /tmp/quotaimg/tmp.ext3 "$path"

# Delete with sudo umount "$path" && rm -rf /tmp/quotaimg

You can now also optionally apply user fs quotas