tree 8712b257dc8b9b43e794a2d1a655e3862a6c977d
parent 32679a82d9542ec26ea8b4e32d29dd7b02202611
author Jeff Sharkey <jsharkey@android.com> 1438106249 -0700
committer Jeff Sharkey <jsharkey@android.com> 1438130831 -0700

Give secondary users read-only physical cards.

Long ago, we mounted secondary physical cards as readable by all
users on the device, which enabled the use-case of loading media on
a card and viewing it from all users.

More recently, we started giving write access to these secondary
physical cards, but this created a one-directional channel for
communication across user boundaries; something that CDD disallows.

This change is designed to give us the best of both worlds: the
package-specific directories are writable for the user that mounted
the card, but access to those "Android" directories are blocked for
all other users.  Other users remain able to read content elsewhere
on the card.

Bug: 22787184
Change-Id: I75dbd339f11402ae774c7e4b8f2b15ee216270e8