How To Iterate Over Files in a Directory

ls is not the command that expands globs to filenames, bash does that. In the following snippet, bash expands /dev/{s,v}*1 and expands it to /dev/sda1 which is what the for loop is then passed.

# This only works if there are no spaces in the file names.
for f in /dev/{s,v}*1
do
    echo "$f"
done