installer: Use slave mount in postinst script.
Currently the postinst script uses shared mount to bind mount /run to
/tmp/*/run, do postinst actions, and then umount it. This has caused
some side effect: the bind mount created by Docker under /run/docker/*
can be accidentally umount-ed when the chromeos-postinst umounts
/tmp/*/run.
One solution would be to make the /tmp/*/run a slave mount, hence
umount does not propagate back to /run folder.
BUG=b:112417598
TEST=manually test
Change-Id: Iaa21363094d8dc90ac0fdb887e554839e5b299a3
Reviewed-on: https://chromium-review.googlesource.com/1194604
Commit-Ready: Xuewei Zhang <xueweiz@google.com>
Tested-by: Xuewei Zhang <xueweiz@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit 2a5a7c18d304ca8dc7c2e3ad008d420b9c461307)
Reviewed-on: https://chromium-review.googlesource.com/1196949
Commit-Queue: Xuewei Zhang <xueweiz@google.com>
diff --git a/installer/chromeos-postinst b/installer/chromeos-postinst
index 2314192..bd8e095 100755
--- a/installer/chromeos-postinst
+++ b/installer/chromeos-postinst
@@ -28,6 +28,7 @@
local d
for d in ${MOUNTS}; do
mount -n --bind "${d}" "./${d}"
+ mount --make-slave "./${d}"
done
chroot . /usr/bin/cros_installer postinst "/" "$@"
