tree b1b63e3ad3cecdc070d1309c482b0e140d3b0ee1
parent 68db15cc2ea5b8314b4c8f7f3920423aeb5e25eb
author Jorge Lucangeli Obes <jorgelo@google.com> 1444690559 -0700
committer Jorge Lucangeli Obes <jorgelo@google.com> 1444690559 -0700

Make Minijail work correctly with shared mounts.

This fixes some problems that appear when system booted with systemd.
Systemd sets all mounts to shared. This means that when minijail0 creates
mount namespace new mounts will propogate out of that namespace.

This change fixes that by setting all mounts to private right after
creating new namespace.
Also when remounting /proc it unmounts it lazily, as normal umount()
may fail when shared mounts are enabled.

More information about shared mounts:
https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt

(Original patch by Andrey Ulanov <andreyu@google.com> at
https://chromium-review.googlesource.com/303158)

Change-Id: I0ff5851dba32524bd6c4ad663b67826fb9be0485