Way to distinguish bind mounted path ?

Host operating system:

Linux css 4.4.68-nx #122 SMP Mon May 15 09:46:11 KST 2017 x86_64 GNU/Linux

node_exporter version:

  build user:       root@bb6d0678e7f3
  build date:       20170321-12:12:54
  go version:       go1.7.5

Are you running node_exporter in Docker?

yes

What did you do that produced an error?

With given query below

node_filesystem_size{instance=~"(css).*",fstype=~"(ext4|xfs)",mountpoint!~".*mapper.*",device!~".*mapper.*"}

Result is

node_filesystem_size{device="/dev/sda1",fstype="ext4",instance="css:9100",job="node",mountpoint="/rootfs"}	21003628544
node_filesystem_size{device="/dev/sda3",fstype="ext4",instance="css:9100",job="node",mountpoint="/rootfs/home"}	857421250560
node_filesystem_size{device="/dev/sda3",fstype="ext4",instance="css:9100",job="node",mountpoint="/rootfs/home1"}	857421250560

Actually second record is bind mounted point.
If I can get mount options it would be helpful, to exclude the record.

Start with the node_filesystem_size metric and the filesystem data exposed for the Docker-hosted node_exporter. Investigate how bind-mounted paths are represented in the reported device, filesystem type, and mountpoint labels, and determine whether mount options can distinguish them. Done means the exporter exposes enough information for the bind-mounted record to be excluded reliably.