tree 1604e80570aa9d37026ccb484b42279c57928c18
parent cb34e8ce650d7e56aaf76552ff79487d52467a37
author Don Garrett <dgarrett@google.com> 1328056696 -0800
committer Gerrit <chrome-bot@google.com> 1328139743 -0800

Revise loopback device handling to be parallelization safe.

Update engine tests were allocating loopback devices in a non-atomic fashion.
When they were run in parallel with other tests that were using loopback
devices, this could lead to two tests using the same device and failing.

This change follows jrbarnette's advice and allocates loopback devices
atomically using "losetup --show -f <file to bind>".

NOTE: integration_unittest.cc is not currently being built or run, and
so the change here has not been verified. I only discovered it wasn't being
built while making this change, and fixing/deleting it seemed out of scope
for the change.

BUG=chromium-os:24975
TEST=Ran unittests

Change-Id: Ica060c8add009cac134e22b46b4e87588d0246e0
Reviewed-on: https://gerrit.chromium.org/gerrit/15128
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Don Garrett <dgarrett@chromium.org>
Commit-Ready: Don Garrett <dgarrett@chromium.org>