Project: mesos
Issue MESOS-3483: LinuxFilesystemIsolator should make the slave's work_dir a shared mount.
So that when a user task is forked, it does not hold extra references to the sandbox mount and provisioner bind backend mounts. If we don't do that, we could get the following error message when cleaning up bind backend mount points and sandbox mount points. {noformat} E0921 17:35:57.268159 47010 bind.cpp:182] Failed to remove rootfs mount point '/var/lib/mesos/provisioner/containers/07eb6660-25ff-4e83-8b2f-06955567e04a/backends/bind/rootfses/30f7e5e2-55d0-4d4d-a662-f8aad0d56b33': Device or resource busy E0921 17:35:57.268349 47010 provisioner.cpp:403] Failed to remove the provisioned container directory at '/var/lib/mesos/provisioner/containers/07eb6660-25ff-4e83-8b2f-06955567e04a': Device or resource busy {noformat}
Story points: 3