Mounting encrypted OBB files has never worked reliably across devices,
partly due to its reliance on Twofish encryption support in the kernel.
This is because Twofish support (CONFIG_CRYPTO_TWOFISH) has never been
required or even recommended for Android. It has never been enabled in
GKI, but even before GKI it wasn't required or recommended. Moreover,
this is now the only Android feature that still uses dm-crypt
(CONFIG_DM_CRYPT), and some devices don't have that enabled either.
Therefore, it appears that this feature is unused. That's perhaps not
surprising, considering that the documentation for OBBs
(https://developer.android.com/google/play/expansion-files) says that
they are deprecated, and also it explains OBBs as being app files that
are opaque to the platform; the ability of the platform to mount OBBs
that happen to be in a particular format is never mentioned. That means
that OBB mounting is probably rarely used even with unencrypted OBBs.
Finally, the usefulness of OBBs having their own encryption layer (in
addition to what the platform already provides via FBE) is not clear
either, especially with such an unusual choice of cipher.
To avoid the confusion that is being caused by having the broken code
for mounting encrypted OBBs still sitting around, let's remove it.
Test: atest StorageManagerTest # on Cuttlefish
Test: atest StorageManagerIntegrationTest # on Cuttlefish
Bug: 216475849
Change-Id: Iaef32cce90f95ea745ba2b143f89e66f533f3479
Helpers to get a block device size in bytes or 512 byte sectors,
using BLKGETSIZE64 and returning value of uint64_t type.
This also removes get_blkdev_size().
Test: build, manual, mount exFAT volume
Bug: 80202067
Change-Id: Ib07e8ac6ef7ff49de0ed570d1fa202e8b558b80c
This moves fstrim, obb and appfuse commands over to the new Binder
interface. This change also separates creating/destroying and
mounting/unmounting of OBB volumes, which means they finally flow
nicely into the modern VolumeInfo/VolumeBase design.
We now generate unique identifiers for all OBB volumes, instead of
using a shady MD5 hash.
Change all "loop" and "dm" devices to tag the kernel resources with
a vold-specific prefix so that we can clean them up if vold crashes;
there are new destroyAll() methods that handle this cleanup.
Move appfuse mounting/unmounting into VolumeManager so it can be
shared. Move various model objects into a separate directory to
tidy things up.
Test: cts-tradefed run commandAndExit cts-dev -m CtsOsTestCases -t android.os.storage.cts.StorageManagerTest
Bug: 13758960
Change-Id: I7294e32b3fb6efe07cb3b77bd20166e70b66958f
