tree a6435f8f69ee22d82aa92fb2012c88d1155a0ad8
parent 6aaedb0dcacfb0e43e89fa833004ec6203bacf1c
author LongPing.WEI <weilongping@huawei.com> 1543374803 +0800
committer Paul Crowley <paulcrowley@google.com> 1544140565 -0800

Do lazy-unmount to /storage directly

From man 2 umount:
MNT_DETACH (since Linux 2.4.11)

Perform a lazy unmount: make the mount point unavailable for new
accesses, immediately disconnect the filesystem and all filesystems
mounted below it from each other and from the mount table, and
actually perform the unmount when the mount point ceases to be busy.

So we don't need to unmount the filesystems under it one by one.

Bug: 113796163
Test: atest android.appsecurity.cts.PermissionsHostTest#testInteractiveGrant23
Change-Id: I6a0422466a9865ff6d17122505ca73d041de9d54