pkg/mount: mountinfo from specified pid

Signed-off-by: Vincent Batts <vbatts@redhat.com>

mount/mountinfo_linux.go

@@ -1,3 +1,5 @@
+// +build linux
+
 package mount
 
 import (
@@ -72,3 +74,14 @@ func parseInfoFile(r io.Reader) ([]*MountInfo, error) {
 	}
 	return out, nil
 }
+
+// PidMountInfo collects the mounts for a specific Pid
+func PidMountInfo(pid int) ([]*MountInfo, error) {
+	f, err := os.Open(fmt.Sprintf("/proc/%d/mountinfo", pid))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return parseInfoFile(f)
+}