commit abe9970863bfe7e9a72e5f81796c8312bbe82db3
author Wai-Hong Tam <waihong@google.com> Mon Apr 17 11:58:17 2017 -0700
committer chrome-bot <chrome-bot@chromium.org> Mon Apr 17 22:50:25 2017 -0700
tree ea9c5d62a85eaf8e94915730fd0aac0953c52094
parent 24f38a57efef89f44fa259a5ee48514d1fac0192

FAFT: Lazy unmount filesystem for probling an USB disk on servo

It happens to fail to unmount the filesystem when running FAFT on a
desktop Ubuntu machine. Ubuntu may auto-mount the filesystem and
pop-up the file browser that interferes the unmount call. Using lazy
unmount helps. It unmounts the filsystem as soon as it is not busy.

BUG=None
TEST=Run FAFT tests requiring an USB disk.

Change-Id: I5dea442f8eef4bd4c89b4a7fe95cae634f48f4cb
Reviewed-on: https://chromium-review.googlesource.com/479639
Commit-Ready: Wai-Hong Tam <waihong@google.com>
Tested-by: Wai-Hong Tam <waihong@google.com>
Reviewed-by: Tyler Reid <twreid@google.com>

server/cros/faft/firmware_test.py

diff --git a/server/cros/faft/firmware_test.py b/server/cros/faft/firmware_test.py
index fdefd4c4..43cb0d2 100644
--- a/server/cros/faft/firmware_test.py
+++ b/server/cros/faft/firmware_test.py
@@ -380,7 +380,7 @@
                 raise error.TestError('USB stick in servo contains a %s '
                     'image, but DUT is a %s' % (usb_board, dut_board))
         finally:
-            for cmd in ('umount %s' % rootfs, 'sync', 'rm -rf %s' % tmpd):
+            for cmd in ('umount -l %s' % rootfs, 'sync', 'rm -rf %s' % tmpd):
                 self.servo.system(cmd)
 
         self.mark_setup_done('usb_check')