Commit graph

111 commits

Author SHA1 Message Date
Eric Biggers
a53a66caed Rename "user key" methods in vold
Rename methods that refer to "user key" to be more precise about what
they mean.  For more details, see the corresponding frameworks/base
changes (I202ebbfd2b4f79fedb3ed120a8ad81500c126894 and
I5894beb97823dced5954e405d779fada49c79e8d).

No change in behavior except for some changed log messages.

Flag: exempt, mechanical refactoring only
Test: presubmit
Change-Id: I9edcb557172395f4f6cf8e837efcc06fcfefb37d
2023-10-19 19:58:46 +00:00
Xin Li
e737fd0a43 Merge Android U (ab/10368041)
Bug: 291102124
Merged-In: Idda5d816c2a012afa35658f1b2d86ae2787c1faf
Change-Id: I9be9d1ad2b5b186bb8276263b3b42297ebfa332f
2023-08-17 16:51:54 -07:00
Paul Lawrence
d73dfd4ab0 Add vdc volume getStorageSize
StorageStatsManager.getTotalBytes currently takes the size of /data and
rounds up to known probable sizes to guess the size of internal storage.
This is not always correct.

Instead, find the device /data is on and get the size of that device.
This should give a more accurate answer.

Bug: 295358118
Test: vdc volume getStorageSize returns storage size
Change-Id: I907892041b1ce2cd72092a9877ac34c12bf3f254
2023-08-14 23:51:39 +00:00
Arnab Sen
f96d81f5cd SM: Change volume mountUserId for new user
When a volume is ejected from a user but not removed from the device
and mounted again by calling StorageManager#mount, the volume is
mounted for the user from which it was last ejected. This causes the
path of the mounted volume to be inaccessible to the current user.

Whenever StorageManager#mount is called, check if the
VolumeInfo#mountUserId is same as the current userId maintained by
StorageManagerService, if it is not, change the mountUserId for the
Volume to the current userId known to StorageManagerService if it
is not the primary volume and the volume is visible.
This change also fixes a bug where the volumes are unmounted for the
wrong user which causes StorageSessionController go out of sync
which would cause errors during mounting the volumes again as it
maintains sessions per user. The bug also caused volume event
broadcasts to be sent to wrong user handles. To solve the issue
add an extra paramter in IVoldListener#onVolumeStateChanged for userId
which will update the copy which is used for informing
StorageSessionController and also for sending broadcasts.

Test: Perform the following steps:
1. Format SD Card as portable storage in system user.
2. Eject the SD Card from Storage Settings.
3. Switch to a non-system user
4. Mount the SD Card again.
5. Check that the Storage Summary is shown correctly instead
   of 0B out of 0B.
Also, checked from the logs the volume state broadcasts are sent to
the correct user handles.

Change-Id: I60b8954cdaee4a54ea6a6299fe5ddda2006faf1c
2023-07-14 09:55:37 +00:00
Martijn Coenen
fb64fa92a9 Merge "Support bind mounting volumes into other volume's mountpoint." am: 35eb1ae88a am: 1968bd5a1b am: ba9d81bfc8
Original change: https://android-review.googlesource.com/c/platform/system/vold/+/2189643

Change-Id: I3a391b569c01bb58363dc02cc8436afc0793c29f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
2022-12-09 08:58:14 +00:00
Martijn Coenen
73e3010a25 Support bind mounting volumes into other volume's mountpoint.
With the way the FUSE mount point are currently setup for emulated
volumes, there can be multiple paths that serve the same files on the
lower filesystem; eg

* /mnt/user/0/emulated/0/Android
* /mnt/user/10/emulated/0/Android

both refer to the same file on the lower filesystem:
* /data/media/0/Android

this is normally not a problem, because cross-user file access is not
allowed, and so the FUSE daemon won't serve files for other users.

With clone profiles this is no longer true however, as their volumes
are accessible by each other.

So, it can happen that an app running in clone profile 10 accesses
"/mnt/user/10/emulated/0/Android", which would be served by the FUSE
daemon for the user 10 filesystem.

At the same time, an app running in the owner profile 0 accesses
"mnt/user/0/emulated/0/Android", which would be served by the FUSE
daemon for the user 0 filesystem.

This can cause page cache inconsistencies, because multiple FUSE daemons
can be running on top of the same entries in the lower filesystem.

To prevent this, use bind mounts to make sure that cross-profile
accesses actually end up in the FUSE daemon to which the volume
belongs: "/mnt/user/10/emulated/0" is bind-mounted to
"/mnt/user/0/emulated/0", and vice-versa.

Bug: 228271997
Test: manual
Change-Id: Iefcbc813670628b329a1a5d408b6126b84991e09
2022-12-07 09:01:27 +00:00
Eric Biggers
8c1659e271 Make the CE key always be encrypted by the synthetic password
When generating a CE key, don't persist it immediately with
kEmptyAuthentication.  Instead, cache it in memory and persist it later
when the secret to protect it with is given.  This is needed to make it
so that the CE key is always encrypted by the user's synthetic password
while it is stored on-disk.  See the corresponding system_server changes
for more information about this design change and its motivation.

As part of this, simplify vold's Binder interface by replacing the three
methods addUserKeyAuth(), clearUserKeyAuth(), and
fixateNewestUserKeyAuth() with a single method setUserKeyProtection().
setUserKeyProtection() handles persisting the key for a new user or
re-encrypting the default-encrypted key for an existing unsecured user.

Bug: 232452368
Ignore-AOSP-First: This depends on frameworks/base changes that can only
                   be submitted to internal master, due to conflicts.
Test: see Ia753ea21bbaca8ef7a90c03fe73b66c896b1536e
Change-Id: Id36ba8ee343ccb6de7ec892c3f600abd636f6ce5
2022-09-06 21:30:36 +00:00
Daeho Jeong
37cf9d79ab Introduce target dirty segment ratio tunable parameter
We introduce a new parameter of target dirty segment ratio,
which can be used to set a target dirty / (dirty + free) segments
ratio. For example, if we set this as 80%, GC sleep time will be
calculated to achieve this ratio in a GC period.

Test: check smart idle maint log of StorageManagerService
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Change-Id: I73f2bcf4bdb810164c174bd0d2518b15d577d5d5
2022-07-04 21:23:46 +00:00
Daeho Jeong
3fd33ece35 Make minimum gc sleep time tunnable
Test: check smart idle maint log of StorageManagerService
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Change-Id: I5a70e4ec2ca895551b6446a9dfd4bb5003a3fbd0
2022-06-23 16:20:45 -07:00
Jaegeuk Kim
f6151b434c Support zoned device with dm-default-key
Note that, encrypt_inplace cannot support zoned device, since it
doesn't support in-place updates. And, dm-default-key will have
a different key.

Bug: 172378121
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
Change-Id: I34cb1e747e0f3faa07c5a4bfeded11fb789a033c
2022-06-07 18:43:54 -07:00
Daeho Jeong
c0de6d8184 Merge changes from topic "change_period"
* changes:
  vold: remove overprovision area from free segments
  vold: do not set gc sleep time with zero dirty segments
  vold: add gc period in setGCUrgentPace
2022-03-25 22:26:12 +00:00
Eric Biggers
b3ea454002 Remove FDE methods from binder interface
Now that none of these methods are used anymore, we can remove them.
Also remove the related constants.

Bug: 208476087
Change-Id: I1f56c8e05fb3fba09aab4bf5f8609b0f552b8999
2022-03-21 05:11:21 +00:00
Daeho Jeong
7c788fc3e9 vold: add gc period in setGCUrgentPace
To make gc period changable, added a new gcPeriod parameter to
setGCUrgentPace.

Test: adb shell device_config put storage_native_boot smart_idle_maint_period 10
Bug: 202283480
Bug: 181079477
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Change-Id: I4e44a80ea5b51d9a7cde69d25e129dd0673b271f
2022-03-18 12:56:17 -07:00
Eric Biggers
90a305232e Remove HardwareAuthToken parameters from binder interface
These are no longer used.

Test: atest com.android.server.locksettings
Bug: 184723544
Change-Id: I6160d30deb138a5366532de84cbf6f02cbc69b8c
(cherry picked from commit 5bb9faab49)
Merged-In: I6160d30deb138a5366532de84cbf6f02cbc69b8c
2022-03-15 01:26:08 +00:00
Eric Biggers
7e79a43a72 Remove broken code for mounting encrypted OBB files
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
2022-03-01 21:19:18 +00:00
Daeho Jeong
999fceb07c Add interfaces required by smart idle maintenance service
Added interfaces required by smart idle maintenance service in
StorageManagerService, whose goal is to determine when to trigger
filesystem defragmentation while keeping the best user experience
as long as possible, and avoiding hurting UFS lifetime.

Test: check smart idle maintenance log every hour
Bug: 202283480
Bug: 181079477
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Change-Id: I012cfb9b01e5d21ec71700c3c52ac9c096cd1a90
2022-01-12 10:54:37 -08:00
Youkichi Hosoi
2991cbe49f Split MOUNT_FLAG_VISIBLE into MOUNT_FLAG_VISIBLE_FOR_{READ, WRITE}
IVold.MOUNT_FLAG_VISIBLE is split into MOUNT_FLAG_VISIBLE_FOR_READ and
MOUNT_FLAG_VISIBLE_FOR_WRITE.
Accordingly, VolumeBase::MountFlags::kVisible is split into
kVisibleForRead and kVisibleForWrite.

Bug: 206019156
Test: m
Change-Id: Ia55673400d9f713f221650e1335a46ba11f6f027
Merged-In: Ia55673400d9f713f221650e1335a46ba11f6f027
2021-11-25 13:04:45 +09:00
Songchun Fan
0e53c1cdb0 [vold] pass along sysfs name in setOptions
Ignore-AOSP-First: Will cherry-pick to AOSP

BUG: 187308584
Test: atest CtsContentTestCases:android.content.pm.cts.PackageManagerShellCommandIncrementalTest#testInstallWithIdSigNoMissingPages
Change-Id: Iacfe6b735458051f2848b1b766c2b00198b397d9
2021-05-10 16:22:40 -07:00
Songchun Fan
046e68abd6 [vold] pass sysfs_name to mount options
Ignore-AOSP-First: Will cherry-pick to AOSP

Test: manual
BUG: 184844615
Change-Id: I216210132f49f55098c0f2d1b8d4e571b22cfcc4
2021-04-29 08:35:43 -07:00
Eric Biggers
23d93638c5 Merge "vold: add getUnlockedUsers() method to Binder interface" into sc-dev 2021-04-13 17:52:02 +00:00
Eric Biggers
1799debfd6 vold: add getUnlockedUsers() method to Binder interface
This is needed so that system_server can remind itself about which users
have their storage unlocked, if system_server is restarted due to a
userspace reboot (soft restart).

Bug: 146206679
Test: see I482ed8017f7bbc8f7d4fd5a2c0f58629317ce4ed
Change-Id: I02f0494d827094bd41bcfe5f63c24e204b728595
2021-04-08 12:29:57 -07:00
Alex Buynytskyy
dcfeaa1d76 Adding an option to shorten the read timeout.
E.g. during installation to protect the system.

Ignore-AOSP-First: this depends on changes to framework and/or incfs and does not make sense without them. We'll merge it at a single large scale merge later.

Bug: 160635296
Test: atest PackageManagerShellCommandTest PackageManagerShellCommandIncrementalTest IncrementalServiceTest PackageManagerServiceTest ChecksumsTest

Change-Id: I5851e1e9dbc8e8c2b331c407002cf7133bf6e35a
2021-04-08 09:58:15 +00:00
Abhijeet Kaur
e715ec1364 Remove unused mount modes and re-number the modes for consistency
Also, add REMOUNT_MODE_ANDROID_WRITABLE to return "/mnt/runtime/write".

Bug: 148454884
Test: builds
Change-Id: I5a38c88f46034c494604bb001cf4d4c400c8f73e
2021-02-24 14:52:37 +00:00
Seth Moore
5a43d61e66 Add support for binding storage encryption to a seed
With this change, vold exposes an API that may be used to bind key
storage encryption keys to a given seed value. The seed value passed to
vold must be consistent across reboots, or key storage keys will not be
derived consistently. The seed is expected to be set very early in boot,
prior to the use of any key storage encryption keys.

This feature is intended to be used for embedded applications such as
in autos, where the seed may be provided by some other component of the
system. In such systems, there is a default user that is automatically
signed in without a PIN or other credentials. By binding the file
encryption to a platform-provided seed, the default user's data gains
additional protection against removal of the Android embedded device
from the integrated system.

Bug: 157501579
Test: Set seed at startup via init.rc. Seed changes fail as expected.
Change-Id: I9b048ec5e045b84c45883724ace2356d4ef6244d
2021-01-26 21:30:19 +00:00
Ricky Wai
a2ca11e49b Add a method in vold to unmount app data and obb dir for testing
This new method will be used in new sm command.
Tests can use this so data and obb dirs are unmounted, and won't
be killed when volume is unmounted.

Bug: 148049767
Test: New sm command able to unmount app's data and obb dirs
Change-Id: Ifbc661ca510e996abd4b7ce1fb195aaa7afc37ad
2021-01-18 13:47:44 +00:00
Alan Stokes
c0e870af67 Merge "Remove ro.vold.level_from_user." 2021-01-12 11:17:50 +00:00
Alan Stokes
e0b7f306c1 Remove ro.vold.level_from_user.
This is on everywhere, we no longer have any need for it.

Fix: 171462631
Test: Presubmits
Change-Id: I240361619acafeee6cac383037887e15a46c0c38
2021-01-05 09:49:24 +00:00
Jaegeuk Kim
0c52c7125f Let vold format the encrypted partition
Bug: 172378121
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
Change-Id: I03997eb4cbf25a80e36ea738c50e0adb7f4013dd
2020-12-22 11:28:50 -08:00
Ricky Wai
bbfb6ea1ac Check if storage app data and obb directories exist in vold
As storage is not mounted in system server, we use vold
to check if storage app data and obb directories exist instead.

We add a method in vold so it only creates app data and obb dirs
if dirs do not exist to speed up app starting time.

Bug: 160336374
Test: Data and obb directories are created when a new app is started
Change-Id: I1bd784d9c9e05463f71433fc782ac4e0c831cbf1
2020-12-03 15:38:03 +00:00
Martijn Coenen
eed957f6a4 Call earlyBootEnded from vdc.
This allows us to determine the place where early boot ends from init.
It also allows fixing a bug where early boot wasn't ended previously on
devices without metadata encryption.

Bug: 168585635
Bug: 173005594
Test: inspect logs
Change-Id: I78775672a7d3c140e007235a10fb1d1bc816fcee
2020-11-12 11:03:27 +01:00
Yo Chiang
0af25a3a98 Add IVold::destroyDsuMetadataKey()
destroyDsuMetadataKey() / destroy_dsu_metadata_key() calls
android::gsi::GetDsuMetadataKeyDir() to query the DSU metadata
encryption key dir and destroy the key.
This releases the resource and allows consecutive DSU installations to
use the same key *directory*, but not the same key *blob*.

Bug: 168571434
Test: 1. Install a DSU system.
  2. Boot the DSU system and reboot back to the host system.
  3. Wipe the DSU installation.
  4. DSU metadata key dir /metadata/vold/metadata_encryption/dsu/dsu is
     destroyed.
Change-Id: Ib851177315a5a266807f46ccfd446de1848232cf
2020-10-13 16:00:43 +08:00
Alan Stokes
be3db7b7ae Enable vold to set level from user.
We want various per-user directories to have their SELinux MLS level
set to restrict access from other users, as an improvement to user
isolation.

We extend vold_prepare_subdirs to implement this if a flag is
set. vold itself then sets the flag based on a new property,
ro.vold.level_from_user. This is to allow testing of further
incremental work to ensure system apps correctly handle the new
restriction on different devices rather than causing immediate
breakage. Eventually this will go away and the restriction will apply
everywhere.

Bug: 141677108
Test: Manual, with and without propery set.
Change-Id: I8e2207bd94b487bdcc09fd4d80b031027dfea1e3
2020-10-02 14:49:25 +01:00
Eric Biggers
4cd238b900 Merge "vold: remove checkEncryption" am: 2d9777bfbf am: 15c0d3e5d0
Original change: https://android-review.googlesource.com/c/platform/system/vold/+/1363339

Change-Id: I23b9a01632b61a92896ae83e2152fa047dd85c48
2020-07-16 21:00:33 +00:00
Eric Biggers
b7a14053c3 vold: remove checkEncryption
The testing-only "checkEncryption" command has been replaced with
VtsKernelEncryptionTest [1].  In particular, the metadata encryption
documentation [2] no longer mentions checkEncryption but rather
recommends running VtsKernelEncryptionTest.  Also, checkEncryption
hasn't really been maintained, and it has some known bugs; it's unclear
that many people ever really used it.

So, just remove it.

[1] https://android.googlesource.com/platform/test/vts-testcase/kernel/+/refs/heads/master/encryption/
[2] https://source.android.com/security/encryption/metadata#tests

Bug: 155037012
Change-Id: I258829c60768fd11aafdf2faad956cecc1ae9826
2020-07-15 11:21:33 -07:00
David Anderson
026ae1a9ac Merge "Add an isCheckpointing() binder call for adb remount." am: b50480bb96 am: 60e41b7084
Original change: https://android-review.googlesource.com/c/platform/system/vold/+/1330854

Change-Id: I0aa0536cfd33f189525115efa07e49930f53b79a
2020-06-18 22:15:56 +00:00
David Anderson
23850d30f6 Add an isCheckpointing() binder call for adb remount.
This is needed so "adb remount" can avoid writing to /data during a
checkpoint.

Bug: 157540389
Test: manual test
Change-Id: I33a691da3b99343acfc1e8ddf68a14504c3bfbe1
2020-06-10 23:52:25 -07:00
Martijn Coenen
23c0445355 vold: Support aborting FUSE connections.
This can be done through binder as well as vdc, using 'vdc volume
abort_fuse'.

Bug: 153411204
Test: adb shell vdc volume abort_fuse
Change-Id: I93e46dc1cd361729cc1162c63520cf73152ea409
2020-05-28 16:07:16 +02:00
Alex Buynytskyy
91e0bf4998 Checking LOADER_USAGE_STATS before enabling read logs.
Bug: b/152633648
Test: atest PackageManagerShellCommandTest PackageManagerShellCommandIncrementalTest
Change-Id: I29bf16d06a013566c8dd08e64be2a23ad805e37d
2020-03-31 16:28:30 -07:00
Yurii Zubrytskyi
d05bcc8070 Expose new IncFS interface through Vold
CL is a part of multi-repository topic and will be merged
to AOSP

Bug: 146080380
Test: manual

Change-Id: I09b33a34ff1ac7f6e415b7bd090c22e7df24d72d
Merged-In: I09b33a34ff1ac7f6e415b7bd090c22e7df24d72d
2020-03-24 14:26:27 -07:00
Ricky Wai
6b12257702 Make storage dirs remount fork() safe
Also, use the pids provided by system server to remount all existing
processes, so we don't need to do the heavy and unreliable scanning in
/proc anymore.

Bug: 149548518
Test: atest AdoptableHostTest
Change-Id: Ifb5b79a3bc5438f36e0d61ec8aec96bdbc60ca13
2020-03-12 18:16:27 +00:00
Martijn Coenen
816f4d94f6 Add fixupAppDir() API.
This can be used to fixup application directories in case they have been
created by some other entity besides vold; the main use case for this
API right now is OBB directories, which can be created by installers
outside of vold; on devices without sdcardfs, such directories and the
files contained therein are not setup correctly. This API will make sure
everything is setup the way it needs to be setup.

Bug: 146419093
Test: inspect OBB dir after install
Change-Id: I2e35b7ac2992dbb21cc950e53651ffc07cfca907
2020-02-19 12:11:34 +01:00
TreeHugger Robot
dd85fe2e5e Merge "Add disk for StubVolume" 2020-02-14 04:35:15 +00:00
Martijn Coenen
8a68a075a2 Remove appDirRoot argument from setupAppDir.
This is no longer needed, because vold can deduce this itself now.

Bug: 146419093
Test: builds
Change-Id: Ib4f4a4109919af683722a63b305b343ef5fe972d
2020-02-12 15:38:45 +01:00
Risan
82e90de23d Add disk for StubVolume
StubVolume is a volume type for ARC++ external storage. Named StubVolume
because it is managed from outside Android (not through Android kernel).

Previously, StubVolume is a diskless volume. However, as mentioned in
jsharkey@ email, a disk is needed for StubVolume to hold "kInternal"
(external storage type that is "external" from Android perspective,
but is "internal" to the device. For example shared directory from
ChromeOS to Android) and "kIndexable" (whether or not a disk should be
indexed by MediaStore).

The addition of disk means we could expose the createStubVolume API to
add a disk flags, which is also introduced in this CL.

Both kInternal and kIndexable will be introduced in separate CL.

Bug: 132796154
Test: Mount/unmount ARC++ removable device in ChromeOS.
Change-Id: I8b77fa1cf50ab38a2892272154dafdb78f079378
2020-02-12 07:42:40 +00:00
Yurii Zubrytskyi
3497cb5be5 Expose new IncFS interface through Vold
CL is a part of multi-repository topic and will be merged
to AOSP

Bug: 146080380
Test: manual

Change-Id: I09b33a34ff1ac7f6e415b7bd090c22e7df24d72d
2020-01-27 22:26:37 -08:00
Barani Muthukumaran
b1927c2a0a vold: Do not cache CE keys in vold
CE keys were cached in vold to support untrusted reset
by a device admin, this is now supported by Locksettingservice
using synthetic password. This change requires a secret to be
provided to retrieve the CE key and re-wrap without the secret
when user removes the credential.

Test: Set credential, remove credential, swipe to none
and vice-versa.
Bug: 26948053
Merged-In: I4cb1c035a472477e70c1ff5bf0b2c3fcfad495e5
Change-Id: I4cb1c035a472477e70c1ff5bf0b2c3fcfad495e5
2020-01-24 00:20:22 +00:00
Paul Crowley
e3d2051668 Merge "vold: Do not cache CE keys in vold" 2020-01-19 21:58:02 +00:00
Barani Muthukumaran
9ad51adeb9 vold: Do not cache CE keys in vold
CE keys were cached in vold to support untrusted reset
by a device admin, this is now supported by Locksettingservice
using synthetic password. This change requires a secret to be
provided to retrieve the CE key and re-wrap without the secret
when user removes the credential.

Test: Set credential, remove credential, swipe to none
and vice-versa.
Bug: 26948053
Change-Id: I4cb1c035a472477e70c1ff5bf0b2c3fcfad495e5
2020-01-16 12:16:25 -08:00
Martijn Coenen
b52eb85297 Add REMOUNT_MODE_ANDROID_WRITABLE.
Constant to indicate a regular scoped storage view, with the sole
exception that Android/ should be writable.

Bug: 134706060
Bug: 146490513
Test: builds
Change-Id: Ifbcd4fd912ed4cc18d7c6e3eab2c582bc862e10c
2020-01-08 15:04:21 +01:00
Martijn Coenen
13ff668775 Replace mkdirs() with setupAppDir().
vold historically offerred functionality to create directories on behalf
of others. This functionality was purely used to create app-specific
data/obb/media dirs. Make this more explicit by renaming the method to
indicate this.

Additionally, in the past, we never needed to care about the UID set on
these directories, because sdcardfs would take care of that for us
automatically. But with sdcardfs going away, we need to make sure the
UID of the app-specific directories is set correctly. Allow the caller
to pass this in as an argument.

Bug: 146419093
Test: atest FuseDaemonHostTest
Change-Id: Ibeb5fdc91b40d53583bc0960ee11c4d640549c34
2019-12-31 15:58:41 +01:00