diff --git a/fs_mgr/Android.bp b/fs_mgr/Android.bp
index 34c64d2..7a88aa3 100644
--- a/fs_mgr/Android.bp
+++ b/fs_mgr/Android.bp
@@ -91,6 +91,7 @@
     },
     header_libs: [
         "libfiemap_headers",
+        "libstorage_literals_headers",
     ],
     export_header_lib_headers: [
         "libfiemap_headers",
@@ -165,7 +166,7 @@
         "libcrypto",
         "libext4_utils",
         "libfec",
-        "libfs_mgr",
+        "libfs_mgr_binder",
         "liblog",
         "liblp",
         "libselinux",
@@ -187,4 +188,26 @@
             ],
         },
     },
+    required: [
+        "clean_scratch_files",
+    ],
+}
+
+cc_binary {
+    name: "clean_scratch_files",
+    defaults: ["fs_mgr_defaults"],
+    shared_libs: [
+        "libbase",
+        "libfs_mgr_binder",
+    ],
+    srcs: [
+        "clean_scratch_files.cpp",
+    ],
+    product_variables: {
+        debuggable: {
+            init_rc: [
+                "clean_scratch_files.rc",
+            ],
+        },
+    },
 }
diff --git a/fs_mgr/clean_scratch_files.cpp b/fs_mgr/clean_scratch_files.cpp
new file mode 100644
index 0000000..42fe35a
--- /dev/null
+++ b/fs_mgr/clean_scratch_files.cpp
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <fs_mgr_overlayfs.h>
+
+int main() {
+    android::fs_mgr::CleanupOldScratchFiles();
+    return 0;
+}
diff --git a/fs_mgr/clean_scratch_files.rc b/fs_mgr/clean_scratch_files.rc
new file mode 100644
index 0000000..738d1aa
--- /dev/null
+++ b/fs_mgr/clean_scratch_files.rc
@@ -0,0 +1,2 @@
+on post-fs-data && property:ro.debuggable=1
+    exec_background - root root -- clean_scratch_files
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index c043754..ca19782 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -48,15 +48,21 @@
 #include <fs_mgr_overlayfs.h>
 #include <fstab/fstab.h>
 #include <libdm/dm.h>
+#include <libfiemap/image_manager.h>
 #include <libgsi/libgsi.h>
 #include <liblp/builder.h>
 #include <liblp/liblp.h>
+#include <storage_literals/storage_literals.h>
 
 #include "fs_mgr_priv.h"
+#include "libfiemap/utility.h"
 
 using namespace std::literals;
 using namespace android::dm;
 using namespace android::fs_mgr;
+using namespace android::storage_literals;
+using android::fiemap::FilesystemHasReliablePinning;
+using android::fiemap::IImageManager;
 
 namespace {
 
@@ -104,6 +110,14 @@
     return false;
 }
 
+namespace android {
+namespace fs_mgr {
+
+void MapScratchPartitionIfNeeded(Fstab*, const std::function<bool(const std::string&)>&) {}
+
+}  // namespace fs_mgr
+}  // namespace android
+
 #else  // ALLOW_ADBD_DISABLE_VERITY == 0
 
 namespace {
@@ -153,6 +167,12 @@
 }
 
 const auto kPhysicalDevice = "/dev/block/by-name/"s;
+constexpr char kScratchImageMetadata[] = "/metadata/gsi/remount/lp_metadata";
+
+// Note: this is meant only for recovery/first-stage init.
+bool ScratchIsOnData() {
+    return fs_mgr_access(kScratchImageMetadata);
+}
 
 bool fs_mgr_update_blk_device(FstabEntry* entry) {
     if (entry->fs_mgr_flags.logical) {
@@ -443,20 +463,37 @@
 bool fs_mgr_overlayfs_teardown_scratch(const std::string& overlay, bool* change) {
     // umount and delete kScratchMountPoint storage if we have logical partitions
     if (overlay != kScratchMountPoint) return true;
-    auto slot_number = fs_mgr_overlayfs_slot_number();
-    auto super_device = fs_mgr_overlayfs_super_device(slot_number);
-    if (!fs_mgr_rw_access(super_device)) return true;
 
     auto save_errno = errno;
     if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {
         fs_mgr_overlayfs_umount_scratch();
     }
+
+    const auto partition_name = android::base::Basename(kScratchMountPoint);
+
+    auto images = IImageManager::Open("remount", 10s);
+    if (images && images->BackingImageExists(partition_name)) {
+#if defined __ANDROID_RECOVERY__
+        if (!images->DisableImage(partition_name)) {
+            return false;
+        }
+#else
+        if (!images->UnmapImageIfExists(partition_name) ||
+            !images->DeleteBackingImage(partition_name)) {
+            return false;
+        }
+#endif
+    }
+
+    auto slot_number = fs_mgr_overlayfs_slot_number();
+    auto super_device = fs_mgr_overlayfs_super_device(slot_number);
+    if (!fs_mgr_rw_access(super_device)) return true;
+
     auto builder = MetadataBuilder::New(super_device, slot_number);
     if (!builder) {
         errno = save_errno;
         return true;
     }
-    const auto partition_name = android::base::Basename(kScratchMountPoint);
     if (builder->FindPartition(partition_name) == nullptr) {
         errno = save_errno;
         return true;
@@ -836,7 +873,8 @@
 // This returns the scratch device that was detected during early boot (first-
 // stage init). If the device was created later, for example during setup for
 // the adb remount command, it can return an empty string since it does not
-// query ImageManager.
+// query ImageManager. (Note that ImageManager in first-stage init will always
+// use device-mapper, since /data is not available to use loop devices.)
 static std::string GetBootScratchDevice() {
     auto& dm = DeviceMapper::Instance();
 
@@ -992,12 +1030,66 @@
     return true;
 }
 
-static bool CanUseSuperPartition(const Fstab& fstab) {
+static bool CreateScratchOnData(std::string* scratch_device, bool* partition_exists, bool* change) {
+    *partition_exists = false;
+    *change = false;
+
+    auto images = IImageManager::Open("remount", 10s);
+    if (!images) {
+        return false;
+    }
+
+    auto partition_name = android::base::Basename(kScratchMountPoint);
+    if (images->GetMappedImageDevice(partition_name, scratch_device)) {
+        *partition_exists = true;
+        return true;
+    }
+
+    BlockDeviceInfo info;
+    PartitionOpener opener;
+    if (!opener.GetInfo(fs_mgr_get_super_partition_name(), &info)) {
+        LERROR << "could not get block device info for super";
+        return false;
+    }
+
+    *change = true;
+
+    // Note: calling RemoveDisabledImages here ensures that we do not race with
+    // clean_scratch_files and accidentally try to map an image that will be
+    // deleted.
+    if (!images->RemoveDisabledImages()) {
+        return false;
+    }
+    if (!images->BackingImageExists(partition_name)) {
+        static constexpr uint64_t kMinimumSize = 16_MiB;
+        static constexpr uint64_t kMaximumSize = 2_GiB;
+
+        uint64_t size = std::clamp(info.size / 2, kMinimumSize, kMaximumSize);
+        auto flags = IImageManager::CREATE_IMAGE_DEFAULT;
+
+        if (!images->CreateBackingImage(partition_name, size, flags)) {
+            LERROR << "could not create scratch image of " << size << " bytes";
+            return false;
+        }
+    }
+    if (!images->MapImageDevice(partition_name, 10s, scratch_device)) {
+        LERROR << "could not map scratch image";
+        return false;
+    }
+    return true;
+}
+
+static bool CanUseSuperPartition(const Fstab& fstab, bool* is_virtual_ab) {
     auto slot_number = fs_mgr_overlayfs_slot_number();
     auto super_device = fs_mgr_overlayfs_super_device(slot_number);
     if (!fs_mgr_rw_access(super_device) || !fs_mgr_overlayfs_has_logical(fstab)) {
         return false;
     }
+    auto metadata = ReadMetadata(super_device, slot_number);
+    if (!metadata) {
+        return false;
+    }
+    *is_virtual_ab = !!(metadata->header.flags & LP_HEADER_FLAG_VIRTUAL_AB_DEVICE);
     return true;
 }
 
@@ -1011,7 +1103,12 @@
     }
 
     // If that fails, see if we can land on super.
-    if (CanUseSuperPartition(fstab)) {
+    bool is_virtual_ab;
+    if (CanUseSuperPartition(fstab, &is_virtual_ab)) {
+        bool can_use_data = false;
+        if (is_virtual_ab && FilesystemHasReliablePinning("/data", &can_use_data) && can_use_data) {
+            return CreateScratchOnData(scratch_device, partition_exists, change);
+        }
         return CreateDynamicScratch(scratch_device, partition_exists, change);
     }
 
@@ -1053,19 +1150,6 @@
     return fs_mgr_overlayfs_mount_scratch(scratch_device, mnt_type);
 }
 
-bool fs_mgr_overlayfs_scratch_can_be_mounted(const std::string& scratch_device) {
-    if (scratch_device.empty()) return false;
-    if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) return false;
-    if (android::base::StartsWith(scratch_device, kPhysicalDevice)) return true;
-    if (fs_mgr_rw_access(scratch_device)) return true;
-    auto slot_number = fs_mgr_overlayfs_slot_number();
-    auto super_device = fs_mgr_overlayfs_super_device(slot_number);
-    if (!fs_mgr_rw_access(super_device)) return false;
-    auto builder = MetadataBuilder::New(super_device, slot_number);
-    if (!builder) return false;
-    return builder->FindPartition(android::base::Basename(kScratchMountPoint)) != nullptr;
-}
-
 bool fs_mgr_overlayfs_invalid() {
     if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) return true;
 
@@ -1114,7 +1198,7 @@
     // if verity is still disabled, i.e. no reboot occurred), and skips calling
     // fs_mgr_overlayfs_mount_all().
     auto scratch_device = GetBootScratchDevice();
-    if (!fs_mgr_overlayfs_scratch_can_be_mounted(scratch_device)) {
+    if (!fs_mgr_rw_access(scratch_device)) {
         return;
     }
     if (!WaitForFile(scratch_device, 10s)) {
@@ -1152,35 +1236,6 @@
     return ret;
 }
 
-std::vector<std::string> fs_mgr_overlayfs_required_devices(Fstab* fstab) {
-    if (fs_mgr_overlayfs_invalid()) return {};
-
-    if (GetEntryForMountPoint(fstab, kScratchMountPoint) != nullptr) {
-        return {};
-    }
-
-    bool want_scratch = false;
-    for (const auto& entry : fs_mgr_overlayfs_candidate_list(*fstab)) {
-        if (fs_mgr_is_verity_enabled(entry)) {
-            continue;
-        }
-        if (fs_mgr_overlayfs_already_mounted(fs_mgr_mount_point(entry.mount_point))) {
-            continue;
-        }
-        want_scratch = true;
-        break;
-    }
-    if (!want_scratch) {
-        return {};
-    }
-
-    auto device = GetBootScratchDevice();
-    if (!device.empty()) {
-        return {device};
-    }
-    return {};
-}
-
 // Returns false if setup not permitted, errno set to last error.
 // If something is altered, set *change.
 bool fs_mgr_overlayfs_setup(const char* backing, const char* mount_point, bool* change,
@@ -1246,13 +1301,27 @@
     return ret;
 }
 
-static bool GetAndMapScratchDeviceIfNeeded(std::string* device, bool* mapped) {
+static bool EnsureScratchMapped(std::string* device, bool* mapped) {
     *mapped = false;
     *device = GetBootScratchDevice();
     if (!device->empty()) {
         return true;
     }
 
+    auto partition_name = android::base::Basename(kScratchMountPoint);
+
+    // Check for scratch on /data first, before looking for a modified super
+    // partition. We should only reach this code in recovery, because scratch
+    // would otherwise always be mapped.
+    auto images = IImageManager::Open("remount", 10s);
+    if (images && images->BackingImageExists(partition_name)) {
+        if (!images->MapImageDevice(partition_name, 10s, device)) {
+            return false;
+        }
+        *mapped = true;
+        return true;
+    }
+
     // Avoid uart spam by first checking for a scratch partition.
     auto metadata_slot = fs_mgr_overlayfs_slot_number();
     auto super_device = fs_mgr_overlayfs_super_device(metadata_slot);
@@ -1261,7 +1330,6 @@
         return false;
     }
 
-    auto partition_name = android::base::Basename(kScratchMountPoint);
     auto partition = FindPartition(*metadata.get(), partition_name);
     if (!partition) {
         return false;
@@ -1281,6 +1349,12 @@
     return true;
 }
 
+static void UnmapScratchDevice() {
+    // This should only be reachable in recovery, where scratch is not
+    // automatically mapped and therefore can be unmapped.
+    DestroyLogicalPartition(android::base::Basename(kScratchMountPoint));
+}
+
 // Returns false if teardown not permitted, errno set to last error.
 // If something is altered, set *change.
 bool fs_mgr_overlayfs_teardown(const char* mount_point, bool* change) {
@@ -1293,7 +1367,7 @@
     bool unmap = false;
     if ((mount_point != nullptr) && !fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {
         std::string scratch_device;
-        if (GetAndMapScratchDeviceIfNeeded(&scratch_device, &unmap)) {
+        if (EnsureScratchMapped(&scratch_device, &unmap)) {
             mount_scratch = fs_mgr_overlayfs_mount_scratch(scratch_device,
                                                            fs_mgr_overlayfs_scratch_mount_type());
         }
@@ -1319,7 +1393,7 @@
         fs_mgr_overlayfs_umount_scratch();
     }
     if (unmap) {
-        DestroyLogicalPartition(android::base::Basename(kScratchMountPoint));
+        UnmapScratchDevice();
     }
     return ret;
 }
@@ -1338,6 +1412,59 @@
     return false;
 }
 
+namespace android {
+namespace fs_mgr {
+
+void MapScratchPartitionIfNeeded(Fstab* fstab,
+                                 const std::function<bool(const std::set<std::string>&)>& init) {
+    if (fs_mgr_overlayfs_invalid()) {
+        return;
+    }
+    if (GetEntryForMountPoint(fstab, kScratchMountPoint) != nullptr) {
+        return;
+    }
+
+    bool want_scratch = false;
+    for (const auto& entry : fs_mgr_overlayfs_candidate_list(*fstab)) {
+        if (fs_mgr_is_verity_enabled(entry)) {
+            continue;
+        }
+        if (fs_mgr_overlayfs_already_mounted(fs_mgr_mount_point(entry.mount_point))) {
+            continue;
+        }
+        want_scratch = true;
+        break;
+    }
+    if (!want_scratch) {
+        return;
+    }
+
+    if (ScratchIsOnData()) {
+        if (auto images = IImageManager::Open("remount", 0ms)) {
+            images->MapAllImages(init);
+        }
+    }
+
+    // Physical or logical partitions will have already been mapped here,
+    // so just ensure /dev/block symlinks exist.
+    auto device = GetBootScratchDevice();
+    if (!device.empty()) {
+        init({android::base::Basename(device)});
+    }
+}
+
+void CleanupOldScratchFiles() {
+    if (!ScratchIsOnData()) {
+        return;
+    }
+    if (auto images = IImageManager::Open("remount", 0ms)) {
+        images->RemoveDisabledImages();
+    }
+}
+
+}  // namespace fs_mgr
+}  // namespace android
+
 #endif  // ALLOW_ADBD_DISABLE_VERITY != 0
 
 bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string& dev) {
diff --git a/fs_mgr/include/fs_mgr_overlayfs.h b/fs_mgr/include/fs_mgr_overlayfs.h
index 9a7381f..34aded9 100644
--- a/fs_mgr/include/fs_mgr_overlayfs.h
+++ b/fs_mgr/include/fs_mgr_overlayfs.h
@@ -16,8 +16,11 @@
 
 #pragma once
 
+#include <functional>
+
 #include <fstab/fstab.h>
 
+#include <set>
 #include <string>
 #include <vector>
 
@@ -38,3 +41,13 @@
     kOverrideCredsRequired,
 };
 OverlayfsValidResult fs_mgr_overlayfs_valid();
+
+namespace android {
+namespace fs_mgr {
+
+void MapScratchPartitionIfNeeded(Fstab* fstab,
+                                 const std::function<bool(const std::set<std::string>&)>& init);
+void CleanupOldScratchFiles();
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/libfiemap/image_manager.cpp b/fs_mgr/libfiemap/image_manager.cpp
index 280318e..0195716 100644
--- a/fs_mgr/libfiemap/image_manager.cpp
+++ b/fs_mgr/libfiemap/image_manager.cpp
@@ -124,7 +124,7 @@
     return images;
 }
 
-bool ImageManager::PartitionExists(const std::string& name) {
+bool ImageManager::BackingImageExists(const std::string& name) {
     if (!MetadataExists(metadata_dir_)) {
         return false;
     }
@@ -135,11 +135,6 @@
     return !!FindPartition(*metadata.get(), name);
 }
 
-bool ImageManager::BackingImageExists(const std::string& name) {
-    auto header_file = GetImageHeaderPath(name);
-    return access(header_file.c_str(), F_OK) == 0;
-}
-
 static bool IsUnreliablePinningAllowed(const std::string& path) {
     return android::base::StartsWith(path, "/data/gsi/dsu/") ||
            android::base::StartsWith(path, "/data/gsi/test/") ||
@@ -261,6 +256,10 @@
         return false;
     }
 
+#if defined __ANDROID_RECOVERY__
+    LOG(ERROR) << "Cannot remove images backed by /data in recovery";
+    return false;
+#else
     std::string message;
     auto header_file = GetImageHeaderPath(name);
     if (!SplitFiemap::RemoveSplitFiles(header_file, &message)) {
@@ -274,6 +273,7 @@
         LOG(ERROR) << "Error removing " << status_file << ": " << message;
     }
     return RemoveImageMetadata(metadata_dir_, name);
+#endif
 }
 
 // Create a block device for an image file, using its extents in its
@@ -507,6 +507,7 @@
 
     auto image_header = GetImageHeaderPath(name);
 
+#if !defined __ANDROID_RECOVERY__
     // If there is a device-mapper node wrapping the block device, then we're
     // able to create another node around it; the dm layer does not carry the
     // exclusion lock down the stack when a mount occurs.
@@ -530,6 +531,13 @@
     } else if (!MapWithLoopDevice(name, timeout_ms, path)) {
         return false;
     }
+#else
+    // In recovery, we can *only* use device-mapper, since partitions aren't
+    // mounted. That also means we cannot call GetBlockDeviceForFile.
+    if (!MapWithDmLinear(*partition_opener_.get(), name, timeout_ms, path)) {
+        return false;
+    }
+#endif
 
     // Set a property so we remember this is mapped.
     auto prop_name = GetStatusPropertyName(name);
diff --git a/fs_mgr/libfiemap/include/libfiemap/image_manager.h b/fs_mgr/libfiemap/include/libfiemap/image_manager.h
index 2c13229..60b98dc 100644
--- a/fs_mgr/libfiemap/include/libfiemap/image_manager.h
+++ b/fs_mgr/libfiemap/include/libfiemap/image_manager.h
@@ -76,7 +76,9 @@
     // Unmap a block device previously mapped with mapBackingImage.
     virtual bool UnmapImageDevice(const std::string& name) = 0;
 
-    // Returns true whether the named backing image exists.
+    // Returns true whether the named backing image exists. This does not check
+    // consistency with the /data partition, so that it can return true in
+    // recovery.
     virtual bool BackingImageExists(const std::string& name) = 0;
 
     // Returns true if the specified image is mapped to a device.
@@ -154,10 +156,6 @@
 
     std::vector<std::string> GetAllBackingImages();
 
-    // Returns true if the named partition exists. This does not check the
-    // consistency of the backing image/data file.
-    bool PartitionExists(const std::string& name);
-
     // Validates that all images still have pinned extents. This will be removed
     // once b/134588268 is fixed.
     bool Validate();
diff --git a/fs_mgr/libstorage_literals/Android.bp b/fs_mgr/libstorage_literals/Android.bp
index 11611dd..beb18ef 100644
--- a/fs_mgr/libstorage_literals/Android.bp
+++ b/fs_mgr/libstorage_literals/Android.bp
@@ -2,5 +2,6 @@
 cc_library_headers {
     name: "libstorage_literals_headers",
     host_supported: true,
+    recovery_available: true,
     export_include_dirs: ["."],
 }
diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index 4226e95..c66f307 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -1160,13 +1160,16 @@
 ret=${?}
 uses_dynamic_scratch=false
 scratch_partition=
+virtual_ab=`get_property ro.virtual_ab.enabled`
 if ${overlayfs_needed}; then
   if [ ${ret} != 0 ]; then
     die -t ${T} "overlay takeover failed"
   fi
   echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
    echo "${ORANGE}[  WARNING ]${NORMAL} overlay takeover not complete" >&2
-  scratch_partition=scratch
+  if [ -z "${virtual_ab}" ]; then
+    scratch_partition=scratch
+  fi
   if echo "${D}" | grep " /mnt/scratch" >/dev/null; then
     echo "${BLUE}[     INFO ]${NORMAL} using ${scratch_partition} dynamic partition for overrides" >&2
   fi
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index 9da32e4..d8c4843 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -591,14 +591,18 @@
     }
 
     // heads up for instantiating required device(s) for overlayfs logic
-    const auto devices = fs_mgr_overlayfs_required_devices(&fstab_);
-    for (auto const& device : devices) {
-        if (android::base::StartsWith(device, "/dev/block/by-name/")) {
-            InitRequiredDevices({basename(device.c_str())});
-        } else {
-            InitMappedDevice(device);
+    auto init_devices = [this](std::set<std::string> devices) -> bool {
+        for (auto iter = devices.begin(); iter != devices.end();) {
+            if (android::base::StartsWith(*iter, "/dev/block/dm-")) {
+                if (!InitMappedDevice(*iter)) return false;
+                iter = devices.erase(iter);
+            } else {
+                iter++;
+            }
         }
-    }
+        return InitRequiredDevices(std::move(devices));
+    };
+    MapScratchPartitionIfNeeded(&fstab_, init_devices);
 
     fs_mgr_overlayfs_mount_all(&fstab_);
 
diff --git a/liblog/Android.bp b/liblog/Android.bp
index 2e87b5b..2cf60e0 100644
--- a/liblog/Android.bp
+++ b/liblog/Android.bp
@@ -21,14 +21,11 @@
     "logger_read.cpp",
     "logger_write.cpp",
     "logprint.cpp",
-]
-liblog_host_sources = [
-    "fake_log_device.cpp",
+    "properties.cpp",
 ]
 liblog_target_sources = [
     "event_tag_map.cpp",
     "log_time.cpp",
-    "properties.cpp",
     "pmsg_reader.cpp",
     "pmsg_writer.cpp",
     "logd_reader.cpp",
@@ -69,10 +66,6 @@
     srcs: liblog_sources,
 
     target: {
-        host: {
-            srcs: liblog_host_sources,
-            cflags: ["-DFAKE_LOG_DEVICE=1"],
-        },
         android: {
             version_script: "liblog.map.txt",
             srcs: liblog_target_sources,
diff --git a/liblog/fake_log_device.cpp b/liblog/fake_log_device.cpp
deleted file mode 100644
index cd4c11e..0000000
--- a/liblog/fake_log_device.cpp
+++ /dev/null
@@ -1,533 +0,0 @@
-/*
- * Copyright (C) 2008-2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-/*
- * Intercepts log messages intended for the Android log device.
- * Messages are printed to stderr.
- */
-
-#include "fake_log_device.h"
-
-#include <ctype.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-
-#include <mutex>
-
-#include <android-base/no_destructor.h>
-#include <android/log.h>
-#include <log/log_id.h>
-#include <log/logprint.h>
-
-#include "logger.h"
-
-#define kMaxTagLen 16 /* from the long-dead utils/Log.cpp */
-
-#define kTagSetSize 16 /* arbitrary */
-
-#if 0
-#define TRACE(...) printf("fake_log_device: " __VA_ARGS__)
-#else
-#define TRACE(...) ((void)0)
-#endif
-
-typedef struct LogState {
-  bool initialized = false;
-  /* global minimum priority */
-  int global_min_priority;
-
-  /* output format */
-  AndroidLogPrintFormat output_format;
-
-  /* tags and priorities */
-  struct {
-    char tag[kMaxTagLen];
-    int minPriority;
-  } tagSet[kTagSetSize];
-} LogState;
-
-static LogState log_state;
-static android::base::NoDestructor<std::mutex> fake_log_mutex;
-
-/*
- * Configure logging based on ANDROID_LOG_TAGS environment variable.  We
- * need to parse a string that looks like
- *
- *   *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i
- *
- * The tag (or '*' for the global level) comes first, followed by a colon
- * and a letter indicating the minimum priority level we're expected to log.
- * This can be used to reveal or conceal logs with specific tags.
- *
- * We also want to check ANDROID_PRINTF_LOG to determine how the output
- * will look.
- */
-void InitializeLogStateLocked() {
-  log_state.initialized = true;
-
-  /* global min priority defaults to "info" level */
-  log_state.global_min_priority = ANDROID_LOG_INFO;
-
-  /*
-   * This is based on the the long-dead utils/Log.cpp code.
-   */
-  const char* tags = getenv("ANDROID_LOG_TAGS");
-  TRACE("Found ANDROID_LOG_TAGS='%s'\n", tags);
-  if (tags != NULL) {
-    int entry = 0;
-
-    while (*tags != '\0') {
-      char tagName[kMaxTagLen];
-      int i, minPrio;
-
-      while (isspace(*tags)) tags++;
-
-      i = 0;
-      while (*tags != '\0' && !isspace(*tags) && *tags != ':' && i < kMaxTagLen) {
-        tagName[i++] = *tags++;
-      }
-      if (i == kMaxTagLen) {
-        TRACE("ERROR: env tag too long (%d chars max)\n", kMaxTagLen - 1);
-        return;
-      }
-      tagName[i] = '\0';
-
-      /* default priority, if there's no ":" part; also zero out '*' */
-      minPrio = ANDROID_LOG_VERBOSE;
-      if (tagName[0] == '*' && tagName[1] == '\0') {
-        minPrio = ANDROID_LOG_DEBUG;
-        tagName[0] = '\0';
-      }
-
-      if (*tags == ':') {
-        tags++;
-        if (*tags >= '0' && *tags <= '9') {
-          if (*tags >= ('0' + ANDROID_LOG_SILENT))
-            minPrio = ANDROID_LOG_VERBOSE;
-          else
-            minPrio = *tags - '\0';
-        } else {
-          switch (*tags) {
-            case 'v':
-              minPrio = ANDROID_LOG_VERBOSE;
-              break;
-            case 'd':
-              minPrio = ANDROID_LOG_DEBUG;
-              break;
-            case 'i':
-              minPrio = ANDROID_LOG_INFO;
-              break;
-            case 'w':
-              minPrio = ANDROID_LOG_WARN;
-              break;
-            case 'e':
-              minPrio = ANDROID_LOG_ERROR;
-              break;
-            case 'f':
-              minPrio = ANDROID_LOG_FATAL;
-              break;
-            case 's':
-              minPrio = ANDROID_LOG_SILENT;
-              break;
-            default:
-              minPrio = ANDROID_LOG_DEFAULT;
-              break;
-          }
-        }
-
-        tags++;
-        if (*tags != '\0' && !isspace(*tags)) {
-          TRACE("ERROR: garbage in tag env; expected whitespace\n");
-          TRACE("       env='%s'\n", tags);
-          return;
-        }
-      }
-
-      if (tagName[0] == 0) {
-        log_state.global_min_priority = minPrio;
-        TRACE("+++ global min prio %d\n", logState->globalMinPriority);
-      } else {
-        log_state.tagSet[entry].minPriority = minPrio;
-        strcpy(log_state.tagSet[entry].tag, tagName);
-        TRACE("+++ entry %d: %s:%d\n", entry, logState->tagSet[entry].tag,
-              logState->tagSet[entry].minPriority);
-        entry++;
-      }
-    }
-  }
-
-  /*
-   * Taken from the long-dead utils/Log.cpp
-   */
-  const char* fstr = getenv("ANDROID_PRINTF_LOG");
-  AndroidLogPrintFormat format;
-  if (fstr == NULL) {
-    format = FORMAT_BRIEF;
-  } else {
-    if (strcmp(fstr, "brief") == 0)
-      format = FORMAT_BRIEF;
-    else if (strcmp(fstr, "process") == 0)
-      format = FORMAT_PROCESS;
-    else if (strcmp(fstr, "tag") == 0)
-      format = FORMAT_PROCESS;
-    else if (strcmp(fstr, "thread") == 0)
-      format = FORMAT_PROCESS;
-    else if (strcmp(fstr, "raw") == 0)
-      format = FORMAT_PROCESS;
-    else if (strcmp(fstr, "time") == 0)
-      format = FORMAT_PROCESS;
-    else if (strcmp(fstr, "long") == 0)
-      format = FORMAT_PROCESS;
-    else
-      format = (AndroidLogPrintFormat)atoi(fstr);  // really?!
-  }
-
-  log_state.output_format = format;
-}
-
-/*
- * Return a human-readable string for the priority level.  Always returns
- * a valid string.
- */
-static const char* getPriorityString(int priority) {
-  /* the first character of each string should be unique */
-  static const char* priorityStrings[] = {"Verbose", "Debug", "Info", "Warn", "Error", "Assert"};
-  int idx;
-
-  idx = (int)priority - (int)ANDROID_LOG_VERBOSE;
-  if (idx < 0 || idx >= (int)(sizeof(priorityStrings) / sizeof(priorityStrings[0])))
-    return "?unknown?";
-  return priorityStrings[idx];
-}
-
-#if defined(_WIN32)
-/*
- * WIN32 does not have writev().
- * Make up something to replace it.
- */
-static ssize_t fake_writev(int fd, const struct iovec* iov, int iovcnt) {
-  ssize_t result = 0;
-  const struct iovec* end = iov + iovcnt;
-  for (; iov < end; iov++) {
-    ssize_t w = write(fd, iov->iov_base, iov->iov_len);
-    if (w != (ssize_t)iov->iov_len) {
-      if (w < 0) return w;
-      return result + w;
-    }
-    result += w;
-  }
-  return result;
-}
-
-#define writev fake_writev
-#endif
-
-/*
- * Write a filtered log message to stderr.
- *
- * Log format parsing taken from the long-dead utils/Log.cpp.
- */
-static void ShowLog(int logPrio, const char* tag, const char* msg) {
-#if !defined(_WIN32)
-  struct tm tmBuf;
-#endif
-  struct tm* ptm;
-  char timeBuf[32];
-  char prefixBuf[128], suffixBuf[128];
-  char priChar;
-  time_t when;
-#if !defined(_WIN32)
-  pid_t pid, tid;
-#else
-  uint32_t pid, tid;
-#endif
-
-  TRACE("LOG %d: %s %s", logPrio, tag, msg);
-
-  priChar = getPriorityString(logPrio)[0];
-  when = time(NULL);
-  pid = tid = getpid();  // find gettid()?
-
-/*
- * Get the current date/time in pretty form
- *
- * It's often useful when examining a log with "less" to jump to
- * a specific point in the file by searching for the date/time stamp.
- * For this reason it's very annoying to have regexp meta characters
- * in the time stamp.  Don't use forward slashes, parenthesis,
- * brackets, asterisks, or other special chars here.
- */
-#if !defined(_WIN32)
-  ptm = localtime_r(&when, &tmBuf);
-#else
-  ptm = localtime(&when);
-#endif
-  // strftime(timeBuf, sizeof(timeBuf), "%Y-%m-%d %H:%M:%S", ptm);
-  strftime(timeBuf, sizeof(timeBuf), "%m-%d %H:%M:%S", ptm);
-
-  /*
-   * Construct a buffer containing the log header and log message.
-   */
-  size_t prefixLen, suffixLen;
-
-  switch (log_state.output_format) {
-    case FORMAT_TAG:
-      prefixLen = snprintf(prefixBuf, sizeof(prefixBuf), "%c/%-8s: ", priChar, tag);
-      strcpy(suffixBuf, "\n");
-      suffixLen = 1;
-      break;
-    case FORMAT_PROCESS:
-      prefixLen = snprintf(prefixBuf, sizeof(prefixBuf), "%c(%5d) ", priChar, pid);
-      suffixLen = snprintf(suffixBuf, sizeof(suffixBuf), "  (%s)\n", tag);
-      break;
-    case FORMAT_THREAD:
-      prefixLen = snprintf(prefixBuf, sizeof(prefixBuf), "%c(%5d:%5d) ", priChar, pid, tid);
-      strcpy(suffixBuf, "\n");
-      suffixLen = 1;
-      break;
-    case FORMAT_RAW:
-      prefixBuf[0] = 0;
-      prefixLen = 0;
-      strcpy(suffixBuf, "\n");
-      suffixLen = 1;
-      break;
-    case FORMAT_TIME:
-      prefixLen = snprintf(prefixBuf, sizeof(prefixBuf), "%s %-8s\n\t", timeBuf, tag);
-      strcpy(suffixBuf, "\n");
-      suffixLen = 1;
-      break;
-    case FORMAT_THREADTIME:
-      prefixLen = snprintf(prefixBuf, sizeof(prefixBuf), "%s %5d %5d %c %-8s \n\t", timeBuf, pid,
-                           tid, priChar, tag);
-      strcpy(suffixBuf, "\n");
-      suffixLen = 1;
-      break;
-    case FORMAT_LONG:
-      prefixLen = snprintf(prefixBuf, sizeof(prefixBuf), "[ %s %5d:%5d %c/%-8s ]\n", timeBuf, pid,
-                           tid, priChar, tag);
-      strcpy(suffixBuf, "\n\n");
-      suffixLen = 2;
-      break;
-    default:
-      prefixLen = snprintf(prefixBuf, sizeof(prefixBuf), "%c/%-8s(%5d): ", priChar, tag, pid);
-      strcpy(suffixBuf, "\n");
-      suffixLen = 1;
-      break;
-  }
-
-  /*
-   * Figure out how many lines there will be.
-   */
-  const char* end = msg + strlen(msg);
-  size_t numLines = 0;
-  const char* p = msg;
-  while (p < end) {
-    if (*p++ == '\n') numLines++;
-  }
-  if (p > msg && *(p - 1) != '\n') {
-    numLines++;
-  }
-
-  /*
-   * Create an array of iovecs large enough to write all of
-   * the lines with a prefix and a suffix.
-   */
-  const size_t INLINE_VECS = 64;
-  const size_t MAX_LINES = ((size_t)~0) / (3 * sizeof(struct iovec*));
-  struct iovec stackVec[INLINE_VECS];
-  struct iovec* vec = stackVec;
-  size_t numVecs;
-
-  if (numLines > MAX_LINES) numLines = MAX_LINES;
-
-  numVecs = numLines * 3;  // 3 iovecs per line.
-  if (numVecs > INLINE_VECS) {
-    vec = (struct iovec*)malloc(sizeof(struct iovec) * numVecs);
-    if (vec == NULL) {
-      msg = "LOG: write failed, no memory";
-      numVecs = INLINE_VECS;
-      numLines = numVecs / 3;
-      vec = stackVec;
-    }
-  }
-
-  /*
-   * Fill in the iovec pointers.
-   */
-  p = msg;
-  struct iovec* v = vec;
-  int totalLen = 0;
-  while (numLines > 0 && p < end) {
-    if (prefixLen > 0) {
-      v->iov_base = prefixBuf;
-      v->iov_len = prefixLen;
-      totalLen += prefixLen;
-      v++;
-    }
-    const char* start = p;
-    while (p < end && *p != '\n') {
-      p++;
-    }
-    if ((p - start) > 0) {
-      v->iov_base = (void*)start;
-      v->iov_len = p - start;
-      totalLen += p - start;
-      v++;
-    }
-    if (*p == '\n') p++;
-    if (suffixLen > 0) {
-      v->iov_base = suffixBuf;
-      v->iov_len = suffixLen;
-      totalLen += suffixLen;
-      v++;
-    }
-    numLines -= 1;
-  }
-
-  /*
-   * Write the entire message to the log file with a single writev() call.
-   * We need to use this rather than a collection of printf()s on a FILE*
-   * because of multi-threading and multi-process issues.
-   *
-   * If the file was not opened with O_APPEND, this will produce interleaved
-   * output when called on the same file from multiple processes.
-   *
-   * If the file descriptor is actually a network socket, the writev()
-   * call may return with a partial write.  Putting the writev() call in
-   * a loop can result in interleaved data.  This can be alleviated
-   * somewhat by wrapping the writev call in the Mutex.
-   */
-
-  for (;;) {
-    int cc = writev(fileno(stderr), vec, v - vec);
-
-    if (cc == totalLen) break;
-
-    if (cc < 0) {
-      if (errno == EINTR) continue;
-
-      /* can't really log the failure; for now, throw out a stderr */
-      fprintf(stderr, "+++ LOG: write failed (errno=%d)\n", errno);
-      break;
-    } else {
-      /* shouldn't happen when writing to file or tty */
-      fprintf(stderr, "+++ LOG: write partial (%d of %d)\n", cc, totalLen);
-      break;
-    }
-  }
-
-  /* if we allocated storage for the iovecs, free it */
-  if (vec != stackVec) free(vec);
-}
-
-/*
- * Receive a log message.  We happen to know that "vector" has three parts:
- *
- *  priority (1 byte)
- *  tag (N bytes -- null-terminated ASCII string)
- *  message (N bytes -- null-terminated ASCII string)
- */
-int FakeWrite(log_id_t log_id, struct timespec*, struct iovec* vector, size_t count) {
-  /* Make sure that no-one frees the LogState while we're using it.
-   * Also guarantees that only one thread is in showLog() at a given
-   * time (if it matters).
-   */
-  auto lock = std::lock_guard{*fake_log_mutex};
-
-  if (!log_state.initialized) {
-    InitializeLogStateLocked();
-  }
-
-  if (log_id == LOG_ID_EVENTS || log_id == LOG_ID_STATS || log_id == LOG_ID_SECURITY) {
-    TRACE("%s: ignoring binary log\n", android_log_id_to_name(log_id));
-    int len = 0;
-    for (size_t i = 0; i < count; ++i) {
-      len += vector[i].iov_len;
-    }
-    return len;
-  }
-
-  if (count != 3) {
-    TRACE("%s: writevLog with count=%d not expected\n", android_log_id_to_name(log_id), count);
-    return -1;
-  }
-
-  /* pull out the three fields */
-  int logPrio = *(const char*)vector[0].iov_base;
-  const char* tag = (const char*)vector[1].iov_base;
-  const char* msg = (const char*)vector[2].iov_base;
-
-  /* see if this log tag is configured */
-  int minPrio = log_state.global_min_priority;
-  for (size_t i = 0; i < kTagSetSize; i++) {
-    if (log_state.tagSet[i].minPriority == ANDROID_LOG_UNKNOWN)
-      break; /* reached end of configured values */
-
-    if (strcmp(log_state.tagSet[i].tag, tag) == 0) {
-      minPrio = log_state.tagSet[i].minPriority;
-      break;
-    }
-  }
-
-  if (logPrio >= minPrio) {
-    ShowLog(logPrio, tag, msg);
-  }
-
-  int len = 0;
-  for (size_t i = 0; i < count; ++i) {
-    len += vector[i].iov_len;
-  }
-  return len;
-}
-
-/*
- * Reset out state.
- *
- * The logger API has no means or need to 'stop' or 'close' using the logs,
- * and as such, there is no way for that 'stop' or 'close' to translate into
- * a close operation to the fake log handler. fakeLogClose is provided for
- * completeness only.
- *
- * We have no intention of adding a log close operation as it would complicate
- * every user of the logging API with no gain since the only valid place to
- * call is in the exit handler. Logging can continue in the exit handler to
- * help debug HOST tools ...
- */
-void FakeClose() {
-  auto lock = std::lock_guard{*fake_log_mutex};
-
-  memset(&log_state, 0, sizeof(log_state));
-}
-
-int __android_log_is_loggable(int prio, const char*, int) {
-  int minimum_priority = __android_log_get_minimum_priority();
-  if (minimum_priority == ANDROID_LOG_DEFAULT) {
-    minimum_priority = ANDROID_LOG_INFO;
-  }
-  return prio >= minimum_priority;
-}
-
-int __android_log_is_loggable_len(int prio, const char*, size_t, int def) {
-  return __android_log_is_loggable(prio, nullptr, def);
-}
-
-int __android_log_is_debuggable() {
-  return 1;
-}
diff --git a/liblog/fake_log_device.h b/liblog/fake_log_device.h
deleted file mode 100644
index 53f1b41..0000000
--- a/liblog/fake_log_device.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include <sys/cdefs.h>
-#include <sys/types.h>
-
-#include <android/log.h>
-
-__BEGIN_DECLS
-
-void FakeClose();
-int FakeWrite(log_id_t log_id, struct timespec* ts, struct iovec* vec, size_t nr);
-
-int __android_log_is_loggable(int prio, const char*, int def);
-int __android_log_is_loggable_len(int prio, const char*, size_t, int def);
-int __android_log_is_debuggable();
-
-__END_DECLS
diff --git a/liblog/logger_read.cpp b/liblog/logger_read.cpp
index e0598de..a0c526b 100644
--- a/liblog/logger_read.cpp
+++ b/liblog/logger_read.cpp
@@ -97,7 +97,7 @@
 
   int ret = 0;
 
-#if (FAKE_LOG_DEVICE == 0)
+#ifdef __ANDROID__
   if (logger_list->mode & ANDROID_LOG_PSTORE) {
     ret = PmsgRead(logger_list, log_msg);
   } else {
@@ -135,7 +135,7 @@
     return;
   }
 
-#if (FAKE_LOG_DEVICE == 0)
+#ifdef __ANDROID__
   if (logger_list->mode & ANDROID_LOG_PSTORE) {
     PmsgClose(logger_list);
   } else {
diff --git a/liblog/logger_write.cpp b/liblog/logger_write.cpp
index ca68296..cf82e0f 100644
--- a/liblog/logger_write.cpp
+++ b/liblog/logger_write.cpp
@@ -40,11 +40,9 @@
 #include "rwlock.h"
 #include "uio.h"
 
-#if (FAKE_LOG_DEVICE == 0)
+#ifdef __ANDROID__
 #include "logd_writer.h"
 #include "pmsg_writer.h"
-#else
-#include "fake_log_device.h"
 #endif
 
 #if defined(__APPLE__)
@@ -105,11 +103,9 @@
  * Release any logger resources. A new log write will immediately re-acquire.
  */
 void __android_log_close() {
-#if (FAKE_LOG_DEVICE == 0)
+#ifdef __ANDROID__
   LogdClose();
   PmsgClose();
-#else
-  FakeClose();
 #endif
 }
 
@@ -311,6 +307,12 @@
 void __android_log_write_logger_data(__android_logger_data* logger_data, const char* msg) {
   ErrnoRestorer errno_restorer;
 
+  if (logger_data->buffer_id != LOG_ID_DEFAULT && logger_data->buffer_id != LOG_ID_MAIN &&
+      logger_data->buffer_id != LOG_ID_SYSTEM && logger_data->buffer_id != LOG_ID_RADIO &&
+      logger_data->buffer_id != LOG_ID_CRASH) {
+    return;
+  }
+
   auto tag_lock = std::shared_lock{default_tag_lock, std::defer_lock};
   if (logger_data->tag == nullptr) {
     tag_lock.lock();
diff --git a/liblog/logprint.cpp b/liblog/logprint.cpp
index 0745a1e..e32878a 100644
--- a/liblog/logprint.cpp
+++ b/liblog/logprint.cpp
@@ -1520,12 +1520,7 @@
  * This code is Android specific, bionic guarantees that
  * calls to non-reentrant getpwuid() are thread safe.
  */
-#if !defined(__MINGW32__)
-#if (FAKE_LOG_DEVICE == 0)
-#ifndef __BIONIC__
-#warning "This code assumes that getpwuid is thread safe, only true with Bionic!"
-#endif
-#endif
+#ifdef __ANDROID__
       struct passwd* pwd = getpwuid(entry->uid);
       if (pwd && (strlen(pwd->pw_name) <= 5)) {
         snprintf(uid, sizeof(uid), "%5s:", pwd->pw_name);
diff --git a/liblog/properties.cpp b/liblog/properties.cpp
index b13662f..f30058a 100644
--- a/liblog/properties.cpp
+++ b/liblog/properties.cpp
@@ -20,8 +20,6 @@
 #include <pthread.h>
 #include <stdlib.h>
 #include <string.h>
-#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
-#include <sys/_system_properties.h>
 #include <unistd.h>
 
 #include <algorithm>
@@ -31,6 +29,10 @@
 
 #include "logger_write.h"
 
+#ifdef __ANDROID__
+#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
+#include <sys/_system_properties.h>
+
 static pthread_mutex_t lock_loggable = PTHREAD_MUTEX_INITIALIZER;
 
 static int lock() {
@@ -647,3 +649,23 @@
 
   return property_size;
 }
+
+#else
+
+int __android_log_is_loggable(int prio, const char*, int) {
+  int minimum_priority = __android_log_get_minimum_priority();
+  if (minimum_priority == ANDROID_LOG_DEFAULT) {
+    minimum_priority = ANDROID_LOG_INFO;
+  }
+  return prio >= minimum_priority;
+}
+
+int __android_log_is_loggable_len(int prio, const char*, size_t, int def) {
+  return __android_log_is_loggable(prio, nullptr, def);
+}
+
+int __android_log_is_debuggable() {
+  return 1;
+}
+
+#endif
\ No newline at end of file
diff --git a/liblog/tests/Android.bp b/liblog/tests/Android.bp
index b3364f9..b4bb77f 100644
--- a/liblog/tests/Android.bp
+++ b/liblog/tests/Android.bp
@@ -104,6 +104,11 @@
     name: "liblog-host-test",
     static_libs: ["liblog"],
     shared_libs: ["libbase"],
-    srcs: ["liblog_host_test.cpp"],
+    srcs: [
+        "liblog_host_test.cpp",
+        "liblog_default_tag.cpp",
+        "liblog_global_state.cpp",
+        "rwlock_test.cpp",
+    ],
     isolated: true,
 }
diff --git a/liblog/tests/liblog_default_tag.cpp b/liblog/tests/liblog_default_tag.cpp
index 5643f63..31b7467 100644
--- a/liblog/tests/liblog_default_tag.cpp
+++ b/liblog/tests/liblog_default_tag.cpp
@@ -22,10 +22,17 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
+#include <android-base/scopeguard.h>
 #include <android/log.h>
 
 #include <gtest/gtest.h>
 
+#ifndef __ANDROID__
+static const char* getprogname() {
+  return program_invocation_short_name;
+}
+#endif
+
 TEST(liblog_default_tag, no_default_tag_libbase_write_first) {
   using namespace android::base;
   bool message_seen = false;
@@ -99,6 +106,7 @@
 }
 
 TEST(liblog_default_tag, default_tag_plus_log_severity) {
+#ifdef __ANDROID__
   using namespace android::base;
   bool message_seen = false;
   std::string expected_tag = "liblog_test_tag";
@@ -110,6 +118,7 @@
 
   auto log_tag_property = "log.tag." + expected_tag;
   SetProperty(log_tag_property, "V");
+  auto reset_tag_property_guard = make_scope_guard([=] { SetProperty(log_tag_property, ""); });
 
   __android_log_buf_write(LOG_ID_MAIN, ANDROID_LOG_VERBOSE, nullptr, "message");
   EXPECT_TRUE(message_seen);
@@ -117,9 +126,13 @@
 
   LOG(VERBOSE) << "message";
   EXPECT_TRUE(message_seen);
+#else
+  GTEST_SKIP() << "No log tag properties on host";
+#endif
 }
 
 TEST(liblog_default_tag, generated_default_tag_plus_log_severity) {
+#ifdef __ANDROID__
   using namespace android::base;
   bool message_seen = false;
   std::string expected_tag = getprogname();
@@ -133,6 +146,7 @@
   // case checks that we can log a Verbose message when log.tag.<getprogname()> is set to 'V'.
   auto log_tag_property = "log.tag." + expected_tag;
   SetProperty(log_tag_property, "V");
+  auto reset_tag_property_guard = make_scope_guard([=] { SetProperty(log_tag_property, ""); });
 
   __android_log_buf_write(LOG_ID_MAIN, ANDROID_LOG_VERBOSE, nullptr, "message");
   EXPECT_TRUE(message_seen);
@@ -140,4 +154,7 @@
 
   LOG(VERBOSE) << "message";
   EXPECT_TRUE(message_seen);
+#else
+  GTEST_SKIP() << "No log tag properties on host";
+#endif
 }
\ No newline at end of file
diff --git a/liblog/tests/liblog_global_state.cpp b/liblog/tests/liblog_global_state.cpp
index 8d73bb8..9a181ef 100644
--- a/liblog/tests/liblog_global_state.cpp
+++ b/liblog/tests/liblog_global_state.cpp
@@ -188,6 +188,7 @@
 }
 
 TEST(liblog_global_state, is_loggable_tag_log_priority_only) {
+#ifdef __ANDROID__
   EXPECT_EQ(0, __android_log_is_loggable(ANDROID_LOG_DEBUG, LOG_TAG, ANDROID_LOG_INFO));
   EXPECT_EQ(1, __android_log_is_loggable(ANDROID_LOG_INFO, LOG_TAG, ANDROID_LOG_INFO));
   EXPECT_EQ(1, __android_log_is_loggable(ANDROID_LOG_WARN, LOG_TAG, ANDROID_LOG_INFO));
@@ -204,9 +205,13 @@
   EXPECT_EQ(1, __android_log_is_loggable(ANDROID_LOG_WARN, LOG_TAG, ANDROID_LOG_INFO));
 
   android::base::SetProperty(log_tag_property, "");
+#else
+  GTEST_SKIP() << "No log tag properties on host";
+#endif
 }
 
 TEST(liblog_global_state, is_loggable_both_set) {
+#ifdef __ANDROID__
   EXPECT_EQ(0, __android_log_is_loggable(ANDROID_LOG_DEBUG, LOG_TAG, ANDROID_LOG_INFO));
   EXPECT_EQ(1, __android_log_is_loggable(ANDROID_LOG_INFO, LOG_TAG, ANDROID_LOG_INFO));
   EXPECT_EQ(1, __android_log_is_loggable(ANDROID_LOG_WARN, LOG_TAG, ANDROID_LOG_INFO));
@@ -240,4 +245,7 @@
   EXPECT_EQ(1, __android_log_is_loggable(ANDROID_LOG_WARN, LOG_TAG, ANDROID_LOG_INFO));
 
   android::base::SetProperty(log_tag_property, "");
+#else
+  GTEST_SKIP() << "No log tag properties on host";
+#endif
 }
diff --git a/liblog/tests/liblog_host_test.cpp b/liblog/tests/liblog_host_test.cpp
index 377550f..ec186d4 100644
--- a/liblog/tests/liblog_host_test.cpp
+++ b/liblog/tests/liblog_host_test.cpp
@@ -20,15 +20,37 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <regex>
+#include <string>
+
+#include <android-base/logging.h>
+#include <android-base/macros.h>
 #include <android-base/stringprintf.h>
-#include <android-base/strings.h>
 #include <android-base/test_utils.h>
 #include <gtest/gtest.h>
 
+using android::base::InitLogging;
+using android::base::StderrLogger;
 using android::base::StringPrintf;
-using android::base::StringReplace;
 
-void GenerateLogContent() {
+static std::string MakeLogPattern(int priority, const char* tag, const char* message) {
+  static const char log_characters[] = "XXVDIWEF";
+  static_assert(arraysize(log_characters) - 1 == ANDROID_LOG_SILENT,
+                "Mismatch in size of log_characters and values in android_LogPriority");
+  priority = priority > ANDROID_LOG_SILENT ? ANDROID_LOG_FATAL : priority;
+  char log_char = log_characters[priority];
+
+  return StringPrintf("%s %c \\d+-\\d+ \\d+:\\d+:\\d+ \\s*\\d+ \\s*\\d+ %s", tag, log_char,
+                      message);
+}
+
+static void CheckMessage(bool expected, const std::string& output, int priority, const char* tag,
+                         const char* message) {
+  std::regex message_regex(MakeLogPattern(priority, tag, message));
+  EXPECT_EQ(expected, std::regex_search(output, message_regex)) << message;
+}
+
+static void GenerateLogContent() {
   __android_log_buf_print(LOG_ID_MAIN, ANDROID_LOG_VERBOSE, "tag", "verbose main");
   __android_log_buf_print(LOG_ID_MAIN, ANDROID_LOG_INFO, "tag", "info main");
   __android_log_buf_print(LOG_ID_MAIN, ANDROID_LOG_ERROR, "tag", "error main");
@@ -52,137 +74,86 @@
 }
 
 TEST(liblog, default_write) {
-  setenv("ANDROID_PRINTF_LOG", "brief", true);
   CapturedStderr captured_stderr;
+  InitLogging(nullptr, StderrLogger);
 
   GenerateLogContent();
 
-  std::string expected_output = StringReplace(R"init(I/tag     (<pid>): info main
-E/tag     (<pid>): error main
-I/tag     (<pid>): info radio
-E/tag     (<pid>): error radio
-I/tag     (<pid>): info system
-E/tag     (<pid>): error system
-I/tag     (<pid>): info crash
-E/tag     (<pid>): error crash
-)init",
-                                              "<pid>", GetPidString(), true);
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose main");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info main");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error main");
 
-  EXPECT_EQ(expected_output, captured_stderr.str());
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose radio");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info radio");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error radio");
+
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose system");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info system");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error system");
+
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose crash");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info crash");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error crash");
 }
 
-TEST(liblog, format) {
-  setenv("ANDROID_PRINTF_LOG", "process", true);
+TEST(liblog, verbose_write) {
+  setenv("ANDROID_LOG_TAGS", "*:v", true);
   CapturedStderr captured_stderr;
+  InitLogging(nullptr, StderrLogger);
 
   GenerateLogContent();
 
-  std::string expected_output = StringReplace(R"init(I(<pid>) info main  (tag)
-E(<pid>) error main  (tag)
-I(<pid>) info radio  (tag)
-E(<pid>) error radio  (tag)
-I(<pid>) info system  (tag)
-E(<pid>) error system  (tag)
-I(<pid>) info crash  (tag)
-E(<pid>) error crash  (tag)
-)init",
-                                              "<pid>", GetPidString(), true);
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose main");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info main");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error main");
 
-  EXPECT_EQ(expected_output, captured_stderr.str());
-  captured_stderr.Stop();
-  captured_stderr.Reset();
-  captured_stderr.Start();
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose radio");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info radio");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error radio");
 
-  // Changing the environment after starting writing doesn't change the format.
-  setenv("ANDROID_PRINTF_LOG", "brief", true);
-  GenerateLogContent();
-  EXPECT_EQ(expected_output, captured_stderr.str());
-  captured_stderr.Stop();
-  captured_stderr.Reset();
-  captured_stderr.Start();
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose system");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info system");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error system");
 
-  // However calling __android_log_close() does reset logging and allow changing the format.
-  __android_log_close();
-  GenerateLogContent();
-
-  expected_output = StringReplace(R"init(I/tag     (<pid>): info main
-E/tag     (<pid>): error main
-I/tag     (<pid>): info radio
-E/tag     (<pid>): error radio
-I/tag     (<pid>): info system
-E/tag     (<pid>): error system
-I/tag     (<pid>): info crash
-E/tag     (<pid>): error crash
-)init",
-                                  "<pid>", GetPidString(), true);
-
-  EXPECT_EQ(expected_output, captured_stderr.str());
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose crash");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info crash");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error crash");
 }
 
-TEST(liblog, filter) {
-  setenv("ANDROID_PRINTF_LOG", "brief", true);
-  setenv("ANDROID_LOG_TAGS", "*:w verbose_tag:v debug_tag:d", true);
-  CapturedStderr captured_stderr;
-
-  auto generate_logs = [](log_id_t log_id) {
-    // Check that we show verbose logs when requesting for a given tag.
-    __android_log_buf_print(log_id, ANDROID_LOG_VERBOSE, "verbose_tag", "verbose verbose_tag");
-    __android_log_buf_print(log_id, ANDROID_LOG_ERROR, "verbose_tag", "error verbose_tag");
-
-    // Check that we don't show verbose logs when explicitly requesting debug+ for a given tag.
-    __android_log_buf_print(log_id, ANDROID_LOG_VERBOSE, "debug_tag", "verbose debug_tag");
-    __android_log_buf_print(log_id, ANDROID_LOG_DEBUG, "debug_tag", "debug debug_tag");
-    __android_log_buf_print(log_id, ANDROID_LOG_ERROR, "debug_tag", "error debug_tag");
-
-    // Check that we don't show info logs when requesting globally warn+.
-    __android_log_buf_print(log_id, ANDROID_LOG_INFO, "default_tag", "info default_tag");
-    __android_log_buf_print(log_id, ANDROID_LOG_WARN, "default_tag", "warn default_tag");
-    __android_log_buf_print(log_id, ANDROID_LOG_ERROR, "default_tag", "error default_tag");
-  };
-
-  auto expected_output = StringReplace(R"init(V/verbose_tag(<pid>): verbose verbose_tag
-E/verbose_tag(<pid>): error verbose_tag
-D/debug_tag(<pid>): debug debug_tag
-E/debug_tag(<pid>): error debug_tag
-W/default_tag(<pid>): warn default_tag
-E/default_tag(<pid>): error default_tag
-)init",
-                                       "<pid>", GetPidString(), true);
-
-  auto test_all_logs = [&] {
-    for (auto log_id : {LOG_ID_MAIN, LOG_ID_SYSTEM, LOG_ID_RADIO, LOG_ID_CRASH}) {
-      generate_logs(log_id);
-      EXPECT_EQ(expected_output, captured_stderr.str());
-      captured_stderr.Stop();
-      captured_stderr.Reset();
-      captured_stderr.Start();
-    }
-  };
-
-  test_all_logs();
-
-  // Changing the environment after starting writing doesn't change the filter.
+TEST(liblog, error_write) {
   setenv("ANDROID_LOG_TAGS", "*:e", true);
-  test_all_logs();
+  CapturedStderr captured_stderr;
+  InitLogging(nullptr, StderrLogger);
 
-  // However calling __android_log_close() does reset logging and allow changing the format.
-  __android_log_close();
-  expected_output = StringReplace(R"init(E/verbose_tag(<pid>): error verbose_tag
-E/debug_tag(<pid>): error debug_tag
-E/default_tag(<pid>): error default_tag
-)init",
-                                  "<pid>", GetPidString(), true);
-  test_all_logs();
+  GenerateLogContent();
+
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose main");
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info main");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error main");
+
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose radio");
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info radio");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error radio");
+
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose system");
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info system");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error system");
+
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_VERBOSE, "tag", "verbose crash");
+  CheckMessage(false, captured_stderr.str(), ANDROID_LOG_INFO, "tag", "info crash");
+  CheckMessage(true, captured_stderr.str(), ANDROID_LOG_ERROR, "tag", "error crash");
 }
 
 TEST(liblog, kernel_no_write) {
   CapturedStderr captured_stderr;
+  InitLogging(nullptr, StderrLogger);
   __android_log_buf_print(LOG_ID_KERNEL, ANDROID_LOG_ERROR, "tag", "kernel error");
   EXPECT_EQ("", captured_stderr.str());
 }
 
 TEST(liblog, binary_no_write) {
   CapturedStderr captured_stderr;
+  InitLogging(nullptr, StderrLogger);
   __android_log_buf_print(LOG_ID_EVENTS, ANDROID_LOG_ERROR, "tag", "error events");
   __android_log_buf_print(LOG_ID_STATS, ANDROID_LOG_ERROR, "tag", "error stats");
   __android_log_buf_print(LOG_ID_SECURITY, ANDROID_LOG_ERROR, "tag", "error security");
diff --git a/set-verity-state/Android.bp b/set-verity-state/Android.bp
index cd8c8c5..da112c9 100644
--- a/set-verity-state/Android.bp
+++ b/set-verity-state/Android.bp
@@ -9,8 +9,9 @@
         "libcrypto_utils",
         "libcutils",
         "libfec",
-        "libfs_mgr",
+        "libfs_mgr_binder",
         "liblog",
+        "libutils",
     ],
     static_libs: [
         "libavb_user",