tree 7b73159d7871a6ef8f4fcac52ee3f612c606fbf0
parent f05058dad7219950fd9bdc2748ab9c9a79d6e7f1
author Qian Zhang <zhq527725@gmail.com> 1589509431 +0800
committer Qian Zhang <zhq527725@gmail.com> 1590743996 +0800

Erased `Info` struct before unmouting volumes in Docker volume isolator.

Currently when `DockerVolumeIsolatorProcess::cleanup()` is called, we will
unmount the volume first, and if the unmount operation fails we will NOT
erase the container's `Info` struct from `infos`. This is problematic
because the remaining `Info` in `infos` will cause the reference count of
the volume is greater than 0, but actually the volume is not being used by
any containers. That means we may never get a chance to unmount this volume
on this agent, furthermore if it is an EBS volume, it cannot be used by any
tasks launched on any other agents since a EBS volume can only be attached
to one node at a time. The only workaround would manually unmount the volume.

So in this patch `DockerVolumeIsolatorProcess::cleanup()` is updated to erase
container's `Info` struct before unmounting volumes.

Review: https://reviews.apache.org/r/72516