Description

When using the "github.com/docker/docker/pkg/mount" package's Mounted function, it falsely claims that a certain path is not mounted when in fact it is. It appears that a path containing spaces is not properly unescaped from /proc/self/mountinfo before being compared.

Steps to reproduce the issue:

1. mount /dev/sdx /mnt/foo\ bar
2. call mount.Mounted("/mnt/foo bar")

Describe the results you received:

false, nil

Describe the results you expected:

true, nil

Additional information you deem important (e.g. issue happens only occasionally):

This is probably something to check for on non-Linux platforms too.