diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp
index 7938a61..45e555f 100644
--- a/debuggerd/debuggerd_test.cpp
+++ b/debuggerd/debuggerd_test.cpp
@@ -16,6 +16,7 @@
 
 #include <err.h>
 #include <fcntl.h>
+#include <malloc.h>
 #include <stdlib.h>
 #include <sys/capability.h>
 #include <sys/mman.h>
@@ -32,7 +33,6 @@
 
 #include <android/fdsan.h>
 #include <android/set_abort_message.h>
-#include <bionic/malloc.h>
 #include <bionic/mte.h>
 #include <bionic/reserved_signals.h>
 
@@ -385,8 +385,7 @@
 
 #if defined(__aarch64__)
 static void SetTagCheckingLevelSync() {
-  HeapTaggingLevel heap_tagging_level = M_HEAP_TAGGING_LEVEL_SYNC;
-  if (!android_mallopt(M_SET_HEAP_TAGGING_LEVEL, &heap_tagging_level, sizeof(heap_tagging_level))) {
+  if (mallopt(M_BIONIC_SET_HEAP_TAGGING_LEVEL, M_HEAP_TAGGING_LEVEL_SYNC) == 0) {
     abort();
   }
 }
diff --git a/fastboot/fastboot.bash b/fastboot/fastboot.bash
index 406e8b8..f5a3384 100644
--- a/fastboot/fastboot.bash
+++ b/fastboot/fastboot.bash
@@ -109,7 +109,7 @@
 
     cur="${COMP_WORDS[COMP_CWORD]}"
     if [[ $i -eq $COMP_CWORD ]]; then
-        partitions="boot bootloader dtbo modem odm odm_dlkm oem product radio recovery system vbmeta vendor vendor_dlkm"
+        partitions="boot bootloader dtbo modem odm odm_dlkm oem product pvmfw radio recovery system vbmeta vendor vendor_dlkm"
         COMPREPLY=( $(compgen -W "$partitions" -- $cur) )
     else
         _fastboot_util_complete_local_file "${cur}" '!*.img'
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 62f6ac7..f7edf8e 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -147,6 +147,7 @@
     { "odm",      "odm.img",          "odm.sig",      "odm",      true,  ImageType::Normal },
     { "odm_dlkm", "odm_dlkm.img",     "odm_dlkm.sig", "odm_dlkm", true,  ImageType::Normal },
     { "product",  "product.img",      "product.sig",  "product",  true,  ImageType::Normal },
+    { "pvmfw",    "pvmfw.img",        "pvmfw.sig",    "pvmfw",    true,  ImageType::BootCritical },
     { "recovery", "recovery.img",     "recovery.sig", "recovery", true,  ImageType::BootCritical },
     { "super",    "super.img",        "super.sig",    "super",    true,  ImageType::Extra },
     { "system",   "system.img",       "system.sig",   "system",   false, ImageType::Normal },
diff --git a/fs_mgr/libsnapshot/cow_api_test.cpp b/fs_mgr/libsnapshot/cow_api_test.cpp
index defe8d4..a96352a 100644
--- a/fs_mgr/libsnapshot/cow_api_test.cpp
+++ b/fs_mgr/libsnapshot/cow_api_test.cpp
@@ -60,6 +60,7 @@
 
 TEST_F(CowTest, ReadWrite) {
     CowOptions options;
+    options.cluster_ops = 0;
     CowWriter writer(options);
 
     ASSERT_TRUE(writer.Initialize(cow_->fd));
@@ -137,6 +138,7 @@
 
 TEST_F(CowTest, CompressGz) {
     CowOptions options;
+    options.cluster_ops = 0;
     options.compression = "gz";
     CowWriter writer(options);
 
@@ -238,6 +240,7 @@
 TEST_F(CowTest, CompressTwoBlocks) {
     CowOptions options;
     options.compression = "gz";
+    options.cluster_ops = 0;
     CowWriter writer(options);
 
     ASSERT_TRUE(writer.Initialize(cow_->fd));
@@ -280,6 +283,7 @@
 TEST_P(CompressionTest, HorribleSink) {
     CowOptions options;
     options.compression = GetParam();
+    options.cluster_ops = 0;
     CowWriter writer(options);
 
     ASSERT_TRUE(writer.Initialize(cow_->fd));
@@ -309,6 +313,7 @@
 
 TEST_F(CowTest, GetSize) {
     CowOptions options;
+    options.cluster_ops = 0;
     CowWriter writer(options);
     if (ftruncate(cow_->fd, 0) < 0) {
         perror("Fails to set temp file size");
@@ -334,6 +339,7 @@
 
 TEST_F(CowTest, AppendLabelSmall) {
     CowOptions options;
+    options.cluster_ops = 0;
     auto writer = std::make_unique<CowWriter>(options);
     ASSERT_TRUE(writer->Initialize(cow_->fd));
 
@@ -399,6 +405,7 @@
 
 TEST_F(CowTest, AppendLabelMissing) {
     CowOptions options;
+    options.cluster_ops = 0;
     auto writer = std::make_unique<CowWriter>(options);
     ASSERT_TRUE(writer->Initialize(cow_->fd));
 
@@ -452,6 +459,7 @@
 
 TEST_F(CowTest, AppendExtendedCorrupted) {
     CowOptions options;
+    options.cluster_ops = 0;
     auto writer = std::make_unique<CowWriter>(options);
     ASSERT_TRUE(writer->Initialize(cow_->fd));
 
@@ -504,6 +512,7 @@
 
 TEST_F(CowTest, AppendbyLabel) {
     CowOptions options;
+    options.cluster_ops = 0;
     auto writer = std::make_unique<CowWriter>(options);
     ASSERT_TRUE(writer->Initialize(cow_->fd));
 
diff --git a/fs_mgr/libsnapshot/cow_snapuserd_test.cpp b/fs_mgr/libsnapshot/cow_snapuserd_test.cpp
index ed67a1c..4cc0fd3 100644
--- a/fs_mgr/libsnapshot/cow_snapuserd_test.cpp
+++ b/fs_mgr/libsnapshot/cow_snapuserd_test.cpp
@@ -239,16 +239,12 @@
     ASSERT_TRUE(rnd_fd > 0);
 
     std::unique_ptr<uint8_t[]> random_buffer_1_ = std::make_unique<uint8_t[]>(size_);
-    std::unique_ptr<uint8_t[]> random_buffer_2_ = std::make_unique<uint8_t[]>(size_);
 
     // Fill random data
     for (size_t j = 0; j < (size_ / 1_MiB); j++) {
         ASSERT_EQ(ReadFullyAtOffset(rnd_fd, (char*)random_buffer_1_.get() + offset, 1_MiB, 0),
                   true);
 
-        ASSERT_EQ(ReadFullyAtOffset(rnd_fd, (char*)random_buffer_2_.get() + offset, 1_MiB, 0),
-                  true);
-
         offset += 1_MiB;
     }
 
@@ -280,7 +276,7 @@
 
     size_t blk_random2_replace_start = blk_zero_copy_end;
 
-    ASSERT_TRUE(writer.AddRawBlocks(blk_random2_replace_start, random_buffer_2_.get(), size_));
+    ASSERT_TRUE(writer.AddRawBlocks(blk_random2_replace_start, random_buffer_1_.get(), size_));
 
     // Flush operations
     ASSERT_TRUE(writer.Finalize());
@@ -292,7 +288,7 @@
     ASSERT_EQ(android::base::ReadFullyAtOffset(base_fd_, orig_buffer_.get(), size_, size_), true);
     memcpy((char*)orig_buffer_.get() + size_, random_buffer_1_.get(), size_);
     memcpy((char*)orig_buffer_.get() + (size_ * 2), (void*)zero_buffer.c_str(), size_);
-    memcpy((char*)orig_buffer_.get() + (size_ * 3), random_buffer_2_.get(), size_);
+    memcpy((char*)orig_buffer_.get() + (size_ * 3), random_buffer_1_.get(), size_);
 }
 
 void CowSnapuserdTest::InitCowDevice() {
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
index fd43cce..22ddfa6 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
@@ -35,7 +35,7 @@
     std::optional<uint64_t> max_blocks;
 
     // Number of CowOperations in a cluster. 0 for no clustering. Cannot be 1.
-    uint32_t cluster_ops = 0;
+    uint32_t cluster_ops = 200;
 };
 
 // Interface for writing to a snapuserd COW. All operations are ordered; merges
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index f8d3cdc..397ff2e 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -306,13 +306,17 @@
     // Helper function for second stage init to restorecon on the rollback indicator.
     static std::string GetGlobalRollbackIndicatorPath();
 
-    // Initiate the transition from first-stage to second-stage snapuserd. This
-    // process involves re-creating the dm-user table entries for each device,
-    // so that they connect to the new daemon. Once all new tables have been
-    // activated, we ask the first-stage daemon to cleanly exit.
-    //
-    // The caller must pass a function which starts snapuserd.
-    bool PerformSecondStageTransition();
+    // Detach dm-user devices from the current snapuserd, and populate
+    // |snapuserd_argv| with the necessary arguments to restart snapuserd
+    // and reattach them.
+    bool DetachSnapuserdForSelinux(std::vector<std::string>* snapuserd_argv);
+
+    // Perform the transition from the selinux stage of snapuserd into the
+    // second-stage of snapuserd. This process involves re-creating the dm-user
+    // table entries for each device, so that they connect to the new daemon.
+    // Once all new tables have been activated, we ask the first-stage daemon
+    // to cleanly exit.
+    bool PerformSecondStageInitTransition();
 
     // ISnapshotManager overrides.
     bool BeginUpdate() override;
@@ -626,6 +630,9 @@
     // The reverse of MapPartitionWithSnapshot.
     bool UnmapPartitionWithSnapshot(LockedFile* lock, const std::string& target_partition_name);
 
+    // Unmap a dm-user device through snapuserd.
+    bool UnmapDmUserDevice(const std::string& snapshot_name);
+
     // If there isn't a previous update, return true. |needs_merge| is set to false.
     // If there is a previous update but the device has not boot into it, tries to cancel the
     //   update and delete any snapshots. Return true if successful. |needs_merge| is set to false.
@@ -693,6 +700,19 @@
     // returns true.
     bool WaitForDevice(const std::string& device, std::chrono::milliseconds timeout_ms);
 
+    enum class InitTransition { SELINUX_DETACH, SECOND_STAGE };
+
+    // Initiate the transition from first-stage to second-stage snapuserd. This
+    // process involves re-creating the dm-user table entries for each device,
+    // so that they connect to the new daemon. Once all new tables have been
+    // activated, we ask the first-stage daemon to cleanly exit.
+    //
+    // If the mode is SELINUX_DETACH, snapuserd_argv must be non-null and will
+    // be populated with a list of snapuserd arguments to pass to execve(). It
+    // is otherwise ignored.
+    bool PerformInitTransition(InitTransition transition,
+                               std::vector<std::string>* snapuserd_argv = nullptr);
+
     std::string gsid_dir_;
     std::string metadata_dir_;
     std::unique_ptr<IDeviceInfo> device_;
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_client.h b/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_client.h
index aa9ba6e..1dab361 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_client.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_client.h
@@ -32,8 +32,6 @@
 
 static constexpr char kSnapuserdSocket[] = "snapuserd";
 
-static constexpr char kSnapuserdFirstStagePidVar[] = "FIRST_STAGE_SNAPUSERD_PID";
-
 // Ensure that the second-stage daemon for snapuserd is running.
 bool EnsureSnapuserdStarted();
 
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_kernel.h b/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_kernel.h
index e8dbe6e..7941e68 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_kernel.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_kernel.h
@@ -50,6 +50,8 @@
 static constexpr uint32_t BLOCK_SIZE = 4096;
 static constexpr uint32_t BLOCK_SHIFT = (__builtin_ffs(BLOCK_SIZE) - 1);
 
+#define DIV_ROUND_UP(n, d) (((n) + (d)-1) / (d))
+
 // This structure represents the kernel COW header.
 // All the below fields should be in Little Endian format.
 struct disk_header {
diff --git a/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h b/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h
index 7aef086..ff0047e 100644
--- a/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h
+++ b/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h
@@ -51,8 +51,8 @@
 extern std::unique_ptr<SnapshotManager> sm;
 extern class TestDeviceInfo* test_device;
 extern std::string fake_super;
-static constexpr uint64_t kSuperSize = 16_MiB + 4_KiB;
-static constexpr uint64_t kGroupSize = 16_MiB;
+static constexpr uint64_t kSuperSize = 32_MiB + 4_KiB;
+static constexpr uint64_t kGroupSize = 32_MiB;
 
 // Redirect requests for "super" to our fake super partition.
 class TestPartitionOpener final : public android::fs_mgr::PartitionOpener {
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 04c3ccc..21b720e 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -676,6 +676,8 @@
         }
     }
 
+    bool compression_enabled = false;
+
     uint64_t total_cow_file_size = 0;
     DmTargetSnapshot::Status initial_target_values = {};
     for (const auto& snapshot : snapshots) {
@@ -692,6 +694,8 @@
             return false;
         }
         total_cow_file_size += snapshot_status.cow_file_size();
+
+        compression_enabled |= snapshot_status.compression_enabled();
     }
 
     if (cow_file_size) {
@@ -703,6 +707,7 @@
     initial_status.set_sectors_allocated(initial_target_values.sectors_allocated);
     initial_status.set_total_sectors(initial_target_values.total_sectors);
     initial_status.set_metadata_sectors(initial_target_values.metadata_sectors);
+    initial_status.set_compression_enabled(compression_enabled);
 
     // Point of no return - mark that we're starting a merge. From now on every
     // snapshot must be a merge target.
@@ -1247,6 +1252,10 @@
         return false;
     }
 
+    if (status.compression_enabled()) {
+        UnmapDmUserDevice(name);
+    }
+
     // Cleanup the base device as well, since it is no longer used. This does
     // not block cleanup.
     auto base_name = GetBaseDeviceName(name);
@@ -1291,12 +1300,13 @@
     return RemoveAllUpdateState(lock, before_cancel);
 }
 
-bool SnapshotManager::PerformSecondStageTransition() {
-    LOG(INFO) << "Performing second-stage transition for snapuserd.";
+bool SnapshotManager::PerformInitTransition(InitTransition transition,
+                                            std::vector<std::string>* snapuserd_argv) {
+    LOG(INFO) << "Performing transition for snapuserd.";
 
     // Don't use EnsuerSnapuserdConnected() because this is called from init,
     // and attempting to do so will deadlock.
-    if (!snapuserd_client_) {
+    if (!snapuserd_client_ && transition != InitTransition::SELINUX_DETACH) {
         snapuserd_client_ = SnapuserdClient::Connect(kSnapuserdSocket, 10s);
         if (!snapuserd_client_) {
             LOG(ERROR) << "Unable to connect to snapuserd";
@@ -1343,6 +1353,9 @@
         }
 
         auto misc_name = user_cow_name;
+        if (transition == InitTransition::SELINUX_DETACH) {
+            misc_name += "-selinux";
+        }
 
         DmTable table;
         table.Emplace<DmTargetUser>(0, target.spec.length, misc_name);
@@ -1378,6 +1391,17 @@
             continue;
         }
 
+        if (transition == InitTransition::SELINUX_DETACH) {
+            auto message = misc_name + "," + cow_image_device + "," + backing_device;
+            snapuserd_argv->emplace_back(std::move(message));
+
+            // Do not attempt to connect to the new snapuserd yet, it hasn't
+            // been started. We do however want to wait for the misc device
+            // to have been created.
+            ok_cows++;
+            continue;
+        }
+
         uint64_t base_sectors =
                 snapuserd_client_->InitDmUserCow(misc_name, cow_image_device, backing_device);
         if (base_sectors == 0) {
@@ -1386,7 +1410,7 @@
             return false;
         }
 
-        CHECK(base_sectors == target.spec.length);
+        CHECK(base_sectors <= target.spec.length);
 
         if (!snapuserd_client_->AttachDmUser(misc_name)) {
             // This error is unrecoverable. We cannot proceed because reads to
@@ -2048,27 +2072,8 @@
 
     auto& dm = DeviceMapper::Instance();
 
-    auto dm_user_name = GetDmUserCowName(name);
-    if (IsCompressionEnabled() && dm.GetState(dm_user_name) != DmDeviceState::INVALID) {
-        if (!EnsureSnapuserdConnected()) {
-            return false;
-        }
-        if (!dm.DeleteDeviceIfExists(dm_user_name)) {
-            LOG(ERROR) << "Cannot unmap " << dm_user_name;
-            return false;
-        }
-
-        if (!snapuserd_client_->WaitForDeviceDelete(dm_user_name)) {
-            LOG(ERROR) << "Failed to wait for " << dm_user_name << " control device to delete";
-            return false;
-        }
-
-        // Ensure the control device is gone so we don't run into ABA problems.
-        auto control_device = "/dev/dm-user/" + dm_user_name;
-        if (!android::fs_mgr::WaitForFileDeleted(control_device, 10s)) {
-            LOG(ERROR) << "Timed out waiting for " << control_device << " to unlink";
-            return false;
-        }
+    if (IsCompressionEnabled() && !UnmapDmUserDevice(name)) {
+        return false;
     }
 
     auto cow_name = GetCowName(name);
@@ -2085,6 +2090,37 @@
     return true;
 }
 
+bool SnapshotManager::UnmapDmUserDevice(const std::string& snapshot_name) {
+    auto& dm = DeviceMapper::Instance();
+
+    if (!EnsureSnapuserdConnected()) {
+        return false;
+    }
+
+    auto dm_user_name = GetDmUserCowName(snapshot_name);
+    if (dm.GetState(dm_user_name) == DmDeviceState::INVALID) {
+        return true;
+    }
+
+    if (!dm.DeleteDeviceIfExists(dm_user_name)) {
+        LOG(ERROR) << "Cannot unmap " << dm_user_name;
+        return false;
+    }
+
+    if (!snapuserd_client_->WaitForDeviceDelete(dm_user_name)) {
+        LOG(ERROR) << "Failed to wait for " << dm_user_name << " control device to delete";
+        return false;
+    }
+
+    // Ensure the control device is gone so we don't run into ABA problems.
+    auto control_device = "/dev/dm-user/" + dm_user_name;
+    if (!android::fs_mgr::WaitForFileDeleted(control_device, 10s)) {
+        LOG(ERROR) << "Timed out waiting for " << control_device << " to unlink";
+        return false;
+    }
+    return true;
+}
+
 bool SnapshotManager::MapAllSnapshots(const std::chrono::milliseconds& timeout_ms) {
     auto lock = LockExclusive();
     if (!lock) return false;
@@ -2254,9 +2290,15 @@
 }
 
 bool SnapshotManager::WriteUpdateState(LockedFile* lock, UpdateState state) {
-    SnapshotUpdateStatus status = {};
+    SnapshotUpdateStatus status;
     status.set_state(state);
-    status.set_compression_enabled(IsCompressionEnabled());
+
+    // If we're transitioning between two valid states (eg, we're not beginning
+    // or ending an OTA), then make sure to propagate the compression bit.
+    if (!(state == UpdateState::Initiated || state == UpdateState::None)) {
+        SnapshotUpdateStatus old_status = ReadSnapshotUpdateStatus(lock);
+        status.set_compression_enabled(old_status.compression_enabled());
+    }
     return WriteSnapshotUpdateStatus(lock, status);
 }
 
@@ -2446,6 +2488,12 @@
     auto lock = LockExclusive();
     if (!lock) return Return::Error();
 
+    auto update_state = ReadUpdateState(lock.get());
+    if (update_state != UpdateState::Initiated) {
+        LOG(ERROR) << "Cannot create update snapshots in state " << update_state;
+        return Return::Error();
+    }
+
     // TODO(b/134949511): remove this check. Right now, with overlayfs mounted, the scratch
     // partition takes up a big chunk of space in super, causing COW images to be created on
     // retrofit Virtual A/B devices.
@@ -2540,6 +2588,14 @@
         return Return::Error();
     }
 
+    SnapshotUpdateStatus status = {};
+    status.set_state(update_state);
+    status.set_compression_enabled(cow_creator.compression_enabled);
+    if (!WriteSnapshotUpdateStatus(lock.get(), status)) {
+        LOG(ERROR) << "Unable to write new update state";
+        return Return::Error();
+    }
+
     created_devices.Release();
     LOG(INFO) << "Successfully created all snapshots for target slot " << target_suffix;
 
@@ -3311,5 +3367,13 @@
     return status.state() != UpdateState::None && status.compression_enabled();
 }
 
+bool SnapshotManager::DetachSnapuserdForSelinux(std::vector<std::string>* snapuserd_argv) {
+    return PerformInitTransition(InitTransition::SELINUX_DETACH, snapuserd_argv);
+}
+
+bool SnapshotManager::PerformSecondStageInitTransition() {
+    return PerformInitTransition(InitTransition::SECOND_STAGE);
+}
+
 }  // namespace snapshot
 }  // namespace android
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index c6a1786..80a6074 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -146,6 +146,7 @@
                 "base-device",
                 "test_partition_b",
                 "test_partition_b-base",
+                "test_partition_b-base",
         };
         for (const auto& partition : partitions) {
             DeleteDevice(partition);
@@ -180,12 +181,22 @@
     }
 
     // If |path| is non-null, the partition will be mapped after creation.
-    bool CreatePartition(const std::string& name, uint64_t size, std::string* path = nullptr) {
+    bool CreatePartition(const std::string& name, uint64_t size, std::string* path = nullptr,
+                         const std::optional<std::string> group = {}) {
         TestPartitionOpener opener(fake_super);
         auto builder = MetadataBuilder::New(opener, "super", 0);
         if (!builder) return false;
 
-        auto partition = builder->AddPartition(name, 0);
+        std::string partition_group = std::string(android::fs_mgr::kDefaultGroup);
+        if (group) {
+            partition_group = *group;
+        }
+        return CreatePartition(builder.get(), name, size, path, partition_group);
+    }
+
+    bool CreatePartition(MetadataBuilder* builder, const std::string& name, uint64_t size,
+                         std::string* path, const std::string& group) {
+        auto partition = builder->AddPartition(name, group, 0);
         if (!partition) return false;
         if (!builder->ResizePartition(partition, size)) {
             return false;
@@ -194,6 +205,8 @@
         // Update the source slot.
         auto metadata = builder->Export();
         if (!metadata) return false;
+
+        TestPartitionOpener opener(fake_super);
         if (!UpdatePartitionTable(opener, "super", *metadata.get(), 0)) {
             return false;
         }
@@ -210,39 +223,54 @@
         return CreateLogicalPartition(params, path);
     }
 
-    bool MapUpdatePartitions() {
+    AssertionResult MapUpdateSnapshot(const std::string& name,
+                                      std::unique_ptr<ICowWriter>* writer) {
         TestPartitionOpener opener(fake_super);
-        auto builder = MetadataBuilder::NewForUpdate(opener, "super", 0, 1);
-        if (!builder) return false;
+        CreateLogicalPartitionParams params{
+                .block_device = fake_super,
+                .metadata_slot = 1,
+                .partition_name = name,
+                .timeout_ms = 10s,
+                .partition_opener = &opener,
+        };
 
-        auto metadata = builder->Export();
-        if (!metadata) return false;
-
-        // Update the destination slot, mark it as updated.
-        if (!UpdatePartitionTable(opener, "super", *metadata.get(), 1)) {
-            return false;
+        auto result = sm->OpenSnapshotWriter(params, {});
+        if (!result) {
+            return AssertionFailure() << "Cannot open snapshot for writing: " << name;
+        }
+        if (!result->Initialize()) {
+            return AssertionFailure() << "Cannot initialize snapshot for writing: " << name;
         }
 
-        for (const auto& partition : metadata->partitions) {
-            CreateLogicalPartitionParams params = {
-                    .block_device = fake_super,
-                    .metadata = metadata.get(),
-                    .partition = &partition,
-                    .force_writable = true,
-                    .timeout_ms = 10s,
-                    .device_name = GetPartitionName(partition) + "-base",
-            };
-            std::string ignore_path;
-            if (!CreateLogicalPartition(params, &ignore_path)) {
-                return false;
-            }
+        if (writer) {
+            *writer = std::move(result);
         }
-        return true;
+        return AssertionSuccess();
+    }
+
+    AssertionResult MapUpdateSnapshot(const std::string& name, std::string* path) {
+        TestPartitionOpener opener(fake_super);
+        CreateLogicalPartitionParams params{
+                .block_device = fake_super,
+                .metadata_slot = 1,
+                .partition_name = name,
+                .timeout_ms = 10s,
+                .partition_opener = &opener,
+        };
+
+        auto result = sm->MapUpdateSnapshot(params, path);
+        if (!result) {
+            return AssertionFailure() << "Cannot open snapshot for writing: " << name;
+        }
+        return AssertionSuccess();
     }
 
     AssertionResult DeleteSnapshotDevice(const std::string& snapshot) {
         AssertionResult res = AssertionSuccess();
         if (!(res = DeleteDevice(snapshot))) return res;
+        if (!sm->UnmapDmUserDevice(snapshot)) {
+            return AssertionFailure() << "Cannot delete dm-user device for " << snapshot;
+        }
         if (!(res = DeleteDevice(snapshot + "-inner"))) return res;
         if (!(res = DeleteDevice(snapshot + "-cow"))) return res;
         if (!image_manager_->UnmapImageIfExists(snapshot + "-cow-img")) {
@@ -289,37 +317,55 @@
 
     // Prepare A/B slot for a partition named "test_partition".
     AssertionResult PrepareOneSnapshot(uint64_t device_size,
-                                       std::string* out_snap_device = nullptr) {
-        std::string base_device, cow_device, snap_device;
-        if (!CreatePartition("test_partition_a", device_size)) {
-            return AssertionFailure();
+                                       std::unique_ptr<ICowWriter>* writer = nullptr) {
+        lock_ = nullptr;
+
+        DeltaArchiveManifest manifest;
+
+        auto group = manifest.mutable_dynamic_partition_metadata()->add_groups();
+        group->set_name("group");
+        group->set_size(device_size * 2);
+        group->add_partition_names("test_partition");
+
+        auto pu = manifest.add_partitions();
+        pu->set_partition_name("test_partition");
+        pu->set_estimate_cow_size(device_size);
+        SetSize(pu, device_size);
+
+        auto extent = pu->add_operations()->add_dst_extents();
+        extent->set_start_block(0);
+        if (device_size) {
+            extent->set_num_blocks(device_size / manifest.block_size());
         }
-        if (!MapUpdatePartitions()) {
-            return AssertionFailure();
+
+        TestPartitionOpener opener(fake_super);
+        auto builder = MetadataBuilder::New(opener, "super", 0);
+        if (!builder) {
+            return AssertionFailure() << "Failed to open MetadataBuilder";
         }
-        if (!dm_.GetDmDevicePathByName("test_partition_b-base", &base_device)) {
-            return AssertionFailure();
+        builder->AddGroup("group_a", 16_GiB);
+        builder->AddGroup("group_b", 16_GiB);
+        if (!CreatePartition(builder.get(), "test_partition_a", device_size, nullptr, "group_a")) {
+            return AssertionFailure() << "Failed create test_partition_a";
         }
-        SnapshotStatus status;
-        status.set_name("test_partition_b");
-        status.set_device_size(device_size);
-        status.set_snapshot_size(device_size);
-        status.set_cow_file_size(device_size);
-        if (!sm->CreateSnapshot(lock_.get(), &status)) {
-            return AssertionFailure();
+
+        if (!sm->CreateUpdateSnapshots(manifest)) {
+            return AssertionFailure() << "Failed to create update snapshots";
         }
-        if (!CreateCowImage("test_partition_b")) {
-            return AssertionFailure();
+
+        if (writer) {
+            auto res = MapUpdateSnapshot("test_partition_b", writer);
+            if (!res) {
+                return res;
+            }
+        } else if (!IsCompressionEnabled()) {
+            std::string ignore;
+            if (!MapUpdateSnapshot("test_partition_b", &ignore)) {
+                return AssertionFailure() << "Failed to map test_partition_b";
+            }
         }
-        if (!MapCowImage("test_partition_b", 10s, &cow_device)) {
-            return AssertionFailure();
-        }
-        if (!sm->MapSnapshot(lock_.get(), "test_partition_b", base_device, cow_device, 10s,
-                             &snap_device)) {
-            return AssertionFailure();
-        }
-        if (out_snap_device) {
-            *out_snap_device = std::move(snap_device);
+        if (!AcquireLock()) {
+            return AssertionFailure() << "Failed to acquire lock";
         }
         return AssertionSuccess();
     }
@@ -328,20 +374,37 @@
     AssertionResult SimulateReboot() {
         lock_ = nullptr;
         if (!sm->FinishedSnapshotWrites(false)) {
-            return AssertionFailure();
+            return AssertionFailure() << "Failed to finish snapshot writes";
         }
-        if (!dm_.DeleteDevice("test_partition_b")) {
-            return AssertionFailure();
+        if (!sm->UnmapUpdateSnapshot("test_partition_b")) {
+            return AssertionFailure() << "Failed to unmap COW for test_partition_b";
         }
-        if (!DestroyLogicalPartition("test_partition_b-base")) {
-            return AssertionFailure();
+        if (!dm_.DeleteDeviceIfExists("test_partition_b")) {
+            return AssertionFailure() << "Failed to delete test_partition_b";
         }
-        if (!sm->UnmapCowImage("test_partition_b")) {
-            return AssertionFailure();
+        if (!dm_.DeleteDeviceIfExists("test_partition_b-base")) {
+            return AssertionFailure() << "Failed to destroy test_partition_b-base";
         }
         return AssertionSuccess();
     }
 
+    std::unique_ptr<SnapshotManager> NewManagerForFirstStageMount(
+            const std::string& slot_suffix = "_a") {
+        auto info = new TestDeviceInfo(fake_super, slot_suffix);
+        return NewManagerForFirstStageMount(info);
+    }
+
+    std::unique_ptr<SnapshotManager> NewManagerForFirstStageMount(TestDeviceInfo* info) {
+        auto init = SnapshotManager::NewForFirstStageMount(info);
+        if (!init) {
+            return nullptr;
+        }
+        init->SetUeventRegenCallback([](const std::string& device) -> bool {
+            return android::fs_mgr::WaitForFile(device, snapshot_timeout_);
+        });
+        return init;
+    }
+
     static constexpr std::chrono::milliseconds snapshot_timeout_ = 5s;
     DeviceMapper& dm_;
     std::unique_ptr<SnapshotManager::LockedFile> lock_;
@@ -439,8 +502,7 @@
 TEST_F(SnapshotTest, CleanFirstStageMount) {
     // If there's no update in progress, there should be no first-stage mount
     // needed.
-    TestDeviceInfo* info = new TestDeviceInfo(fake_super);
-    auto sm = SnapshotManager::NewForFirstStageMount(info);
+    auto sm = NewManagerForFirstStageMount();
     ASSERT_NE(sm, nullptr);
     ASSERT_FALSE(sm->NeedSnapshotsInFirstStageMount());
 }
@@ -449,8 +511,7 @@
     ASSERT_TRUE(sm->FinishedSnapshotWrites(false));
 
     // We didn't change the slot, so we shouldn't need snapshots.
-    TestDeviceInfo* info = new TestDeviceInfo(fake_super);
-    auto sm = SnapshotManager::NewForFirstStageMount(info);
+    auto sm = NewManagerForFirstStageMount();
     ASSERT_NE(sm, nullptr);
     ASSERT_FALSE(sm->NeedSnapshotsInFirstStageMount());
 
@@ -462,32 +523,30 @@
     ASSERT_TRUE(AcquireLock());
 
     static const uint64_t kDeviceSize = 1024 * 1024;
-    std::string snap_device;
-    ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize, &snap_device));
 
-    std::string test_string = "This is a test string.";
-    {
-        unique_fd fd(open(snap_device.c_str(), O_RDWR | O_CLOEXEC | O_SYNC));
-        ASSERT_GE(fd, 0);
-        ASSERT_TRUE(android::base::WriteFully(fd, test_string.data(), test_string.size()));
-    }
-
-    // Note: we know there is no inner/outer dm device since we didn't request
-    // a linear segment.
-    DeviceMapper::TargetInfo target;
-    ASSERT_TRUE(sm->IsSnapshotDevice("test_partition_b", &target));
-    ASSERT_EQ(DeviceMapper::GetTargetType(target.spec), "snapshot");
+    std::unique_ptr<ICowWriter> writer;
+    ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize, &writer));
 
     // Release the lock.
     lock_ = nullptr;
 
+    std::string test_string = "This is a test string.";
+    test_string.resize(writer->options().block_size);
+    ASSERT_TRUE(writer->AddRawBlocks(0, test_string.data(), test_string.size()));
+    ASSERT_TRUE(writer->Finalize());
+    writer = nullptr;
+
     // Done updating.
     ASSERT_TRUE(sm->FinishedSnapshotWrites(false));
 
+    ASSERT_TRUE(sm->UnmapUpdateSnapshot("test_partition_b"));
+
     test_device->set_slot_suffix("_b");
+    ASSERT_TRUE(sm->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
     ASSERT_TRUE(sm->InitiateMerge());
 
     // The device should have been switched to a snapshot-merge target.
+    DeviceMapper::TargetInfo target;
     ASSERT_TRUE(sm->IsSnapshotDevice("test_partition_b", &target));
     ASSERT_EQ(DeviceMapper::GetTargetType(target.spec), "snapshot-merge");
 
@@ -503,7 +562,7 @@
     // Test that we can read back the string we wrote to the snapshot. Note
     // that the base device is gone now. |snap_device| contains the correct
     // partition.
-    unique_fd fd(open(snap_device.c_str(), O_RDONLY | O_CLOEXEC));
+    unique_fd fd(open("/dev/block/mapper/test_partition_b", O_RDONLY | O_CLOEXEC));
     ASSERT_GE(fd, 0);
 
     std::string buffer(test_string.size(), '\0');
@@ -518,7 +577,7 @@
     ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize));
     ASSERT_TRUE(SimulateReboot());
 
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -547,7 +606,7 @@
     FormatFakeSuper();
     ASSERT_TRUE(CreatePartition("test_partition_b", kDeviceSize));
 
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -574,7 +633,7 @@
     ASSERT_TRUE(PrepareOneSnapshot(kDeviceSize));
     ASSERT_TRUE(SimulateReboot());
 
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -795,15 +854,15 @@
         group_->add_partition_names("prd");
         sys_ = manifest_.add_partitions();
         sys_->set_partition_name("sys");
-        sys_->set_estimate_cow_size(6_MiB);
+        sys_->set_estimate_cow_size(2_MiB);
         SetSize(sys_, 3_MiB);
         vnd_ = manifest_.add_partitions();
         vnd_->set_partition_name("vnd");
-        vnd_->set_estimate_cow_size(6_MiB);
+        vnd_->set_estimate_cow_size(2_MiB);
         SetSize(vnd_, 3_MiB);
         prd_ = manifest_.add_partitions();
         prd_->set_partition_name("prd");
-        prd_->set_estimate_cow_size(6_MiB);
+        prd_->set_estimate_cow_size(2_MiB);
         SetSize(prd_, 3_MiB);
 
         // Initialize source partition metadata using |manifest_|.
@@ -899,47 +958,7 @@
         return AssertionSuccess();
     }
 
-    AssertionResult MapUpdateSnapshot(const std::string& name,
-                                      std::unique_ptr<ICowWriter>* writer) {
-        CreateLogicalPartitionParams params{
-                .block_device = fake_super,
-                .metadata_slot = 1,
-                .partition_name = name,
-                .timeout_ms = 10s,
-                .partition_opener = opener_.get(),
-        };
-
-        auto result = sm->OpenSnapshotWriter(params, {});
-        if (!result) {
-            return AssertionFailure() << "Cannot open snapshot for writing: " << name;
-        }
-        if (!result->Initialize()) {
-            return AssertionFailure() << "Cannot initialize snapshot for writing: " << name;
-        }
-
-        if (writer) {
-            *writer = std::move(result);
-        }
-        return AssertionSuccess();
-    }
-
-    AssertionResult MapUpdateSnapshot(const std::string& name, std::string* path) {
-        CreateLogicalPartitionParams params{
-                .block_device = fake_super,
-                .metadata_slot = 1,
-                .partition_name = name,
-                .timeout_ms = 10s,
-                .partition_opener = opener_.get(),
-        };
-
-        auto result = sm->MapUpdateSnapshot(params, path);
-        if (!result) {
-            return AssertionFailure() << "Cannot open snapshot for writing: " << name;
-        }
-        return AssertionSuccess();
-    }
-
-    AssertionResult MapUpdateSnapshot(const std::string& name) {
+    AssertionResult MapOneUpdateSnapshot(const std::string& name) {
         if (IsCompressionEnabled()) {
             std::unique_ptr<ICowWriter> writer;
             return MapUpdateSnapshot(name, &writer);
@@ -983,7 +1002,7 @@
     AssertionResult MapUpdateSnapshots(const std::vector<std::string>& names = {"sys_b", "vnd_b",
                                                                                 "prd_b"}) {
         for (const auto& name : names) {
-            auto res = MapUpdateSnapshot(name);
+            auto res = MapOneUpdateSnapshot(name);
             if (!res) {
                 return res;
             }
@@ -1031,11 +1050,17 @@
         ASSERT_TRUE(sm->UnmapUpdateSnapshot(name));
     }
 
-    // Grow all partitions.
+    // Grow all partitions. Set |prd| large enough that |sys| and |vnd|'s COWs
+    // fit in super, but not |prd|.
     constexpr uint64_t partition_size = 3788_KiB;
     SetSize(sys_, partition_size);
     SetSize(vnd_, partition_size);
-    SetSize(prd_, partition_size);
+    SetSize(prd_, 18_MiB);
+
+    // Make sure |prd| does not fit in super at all. On VABC, this means we
+    // fake an extra large COW for |vnd| to fill up super.
+    vnd_->set_estimate_cow_size(30_MiB);
+    prd_->set_estimate_cow_size(30_MiB);
 
     AddOperationForPartitions();
 
@@ -1047,11 +1072,7 @@
     auto tgt = MetadataBuilder::New(*opener_, "super", 1);
     ASSERT_NE(tgt, nullptr);
     ASSERT_NE(nullptr, tgt->FindPartition("sys_b-cow"));
-    if (IsCompressionEnabled()) {
-        ASSERT_EQ(nullptr, tgt->FindPartition("vnd_b-cow"));
-    } else {
-        ASSERT_NE(nullptr, tgt->FindPartition("vnd_b-cow"));
-    }
+    ASSERT_NE(nullptr, tgt->FindPartition("vnd_b-cow"));
     ASSERT_EQ(nullptr, tgt->FindPartition("prd_b-cow"));
 
     // Write some data to target partitions.
@@ -1070,7 +1091,7 @@
     ASSERT_TRUE(UnmapAll());
 
     // After reboot, init does first stage mount.
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1085,6 +1106,7 @@
 
     // Initiate the merge and wait for it to be completed.
     ASSERT_TRUE(init->InitiateMerge());
+    ASSERT_EQ(init->IsSnapuserdRequired(), IsCompressionEnabled());
     ASSERT_EQ(UpdateState::MergeCompleted, init->ProcessUpdateState());
 
     // Check that the target partitions have the same content after the merge.
@@ -1109,6 +1131,7 @@
     SetSize(sys_, 4_MiB);  // grows
     SetSize(vnd_, 2_MiB);  // shrinks
     // prd_b is unchanged
+    ASSERT_TRUE(sm->BeginUpdate());
     ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
     ASSERT_EQ(4_MiB, GetSnapshotSize("sys_b").value_or(0));
 }
@@ -1118,6 +1141,7 @@
 TEST_F(SnapshotUpdateTest, CowPartitionDoNotTakeOldPartitions) {
     SetSize(sys_, 2_MiB);  // shrinks
     // vnd_b and prd_b are unchanged.
+    ASSERT_TRUE(sm->BeginUpdate());
     ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
 
     auto tgt = MetadataBuilder::New(*opener_, "super", 1);
@@ -1202,7 +1226,7 @@
     ASSERT_TRUE(UnmapAll());
 
     // After reboot, init does first stage mount.
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1214,7 +1238,7 @@
 
     // Simulate shutting down the device again.
     ASSERT_TRUE(UnmapAll());
-    init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_a"));
+    init = NewManagerForFirstStageMount("_a");
     ASSERT_NE(init, nullptr);
     ASSERT_FALSE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1241,6 +1265,11 @@
 
 // Test that at the second update, old COW partition spaces are reclaimed.
 TEST_F(SnapshotUpdateTest, ReclaimCow) {
+    // Make sure VABC cows are small enough that they fit in fake_super.
+    sys_->set_estimate_cow_size(64_KiB);
+    vnd_->set_estimate_cow_size(64_KiB);
+    prd_->set_estimate_cow_size(64_KiB);
+
     // Execute the first update.
     ASSERT_TRUE(sm->BeginUpdate());
     ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
@@ -1251,7 +1280,7 @@
     ASSERT_TRUE(UnmapAll());
 
     // After reboot, init does first stage mount.
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1357,9 +1386,13 @@
 
 TEST_F(SnapshotUpdateTest, MergeCannotRemoveCow) {
     // Make source partitions as big as possible to force COW image to be created.
-    SetSize(sys_, 5_MiB);
-    SetSize(vnd_, 5_MiB);
-    SetSize(prd_, 5_MiB);
+    SetSize(sys_, 10_MiB);
+    SetSize(vnd_, 10_MiB);
+    SetSize(prd_, 10_MiB);
+    sys_->set_estimate_cow_size(12_MiB);
+    vnd_->set_estimate_cow_size(12_MiB);
+    prd_->set_estimate_cow_size(12_MiB);
+
     src_ = MetadataBuilder::New(*opener_, "super", 0);
     ASSERT_NE(src_, nullptr);
     src_->RemoveGroupAndPartitions(group_->name() + "_a");
@@ -1387,8 +1420,8 @@
     ASSERT_TRUE(UnmapAll());
 
     // After reboot, init does first stage mount.
-    // Normally we should use NewForFirstStageMount, but if so, "gsid.mapped_image.sys_b-cow-img"
-    // won't be set.
+    // Normally we should use NewManagerForFirstStageMount, but if so,
+    // "gsid.mapped_image.sys_b-cow-img" won't be set.
     auto init = SnapshotManager::New(new TestDeviceInfo(fake_super, "_b"));
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1495,7 +1528,7 @@
     ASSERT_TRUE(UnmapAll());
 
     // After reboot, init does first stage mount.
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1509,7 +1542,7 @@
     // Simulate a reboot into recovery.
     auto test_device = std::make_unique<TestDeviceInfo>(fake_super, "_b");
     test_device->set_recovery(true);
-    new_sm = SnapshotManager::NewForFirstStageMount(test_device.release());
+    new_sm = NewManagerForFirstStageMount(test_device.release());
 
     ASSERT_TRUE(new_sm->HandleImminentDataWipe());
     ASSERT_EQ(new_sm->GetUpdateState(), UpdateState::None);
@@ -1527,7 +1560,7 @@
     ASSERT_TRUE(UnmapAll());
 
     // After reboot, init does first stage mount.
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1541,7 +1574,7 @@
     // Simulate a reboot into recovery.
     auto test_device = std::make_unique<TestDeviceInfo>(fake_super, "_b");
     test_device->set_recovery(true);
-    new_sm = SnapshotManager::NewForFirstStageMount(test_device.release());
+    new_sm = NewManagerForFirstStageMount(test_device.release());
 
     ASSERT_TRUE(new_sm->FinishMergeInRecovery());
 
@@ -1551,12 +1584,12 @@
 
     // Finish the merge in a normal boot.
     test_device = std::make_unique<TestDeviceInfo>(fake_super, "_b");
-    init = SnapshotManager::NewForFirstStageMount(test_device.release());
+    init = NewManagerForFirstStageMount(test_device.release());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
     init = nullptr;
 
     test_device = std::make_unique<TestDeviceInfo>(fake_super, "_b");
-    new_sm = SnapshotManager::NewForFirstStageMount(test_device.release());
+    new_sm = NewManagerForFirstStageMount(test_device.release());
     ASSERT_EQ(new_sm->ProcessUpdateState(), UpdateState::MergeCompleted);
     ASSERT_EQ(new_sm->ProcessUpdateState(), UpdateState::None);
 }
@@ -1575,7 +1608,7 @@
     // Simulate a reboot into recovery.
     auto test_device = new TestDeviceInfo(fake_super, "_b");
     test_device->set_recovery(true);
-    auto new_sm = SnapshotManager::NewForFirstStageMount(test_device);
+    auto new_sm = NewManagerForFirstStageMount(test_device);
 
     ASSERT_TRUE(new_sm->HandleImminentDataWipe());
     // Manually mount metadata so that we can call GetUpdateState() below.
@@ -1600,7 +1633,7 @@
     // Simulate a rollback, with reboot into recovery.
     auto test_device = new TestDeviceInfo(fake_super, "_a");
     test_device->set_recovery(true);
-    auto new_sm = SnapshotManager::NewForFirstStageMount(test_device);
+    auto new_sm = NewManagerForFirstStageMount(test_device);
 
     ASSERT_TRUE(new_sm->HandleImminentDataWipe());
     EXPECT_EQ(new_sm->GetUpdateState(), UpdateState::None);
@@ -1628,7 +1661,7 @@
     // Simulate a reboot into recovery.
     auto test_device = new TestDeviceInfo(fake_super, "_b");
     test_device->set_recovery(true);
-    auto new_sm = SnapshotManager::NewForFirstStageMount(test_device);
+    auto new_sm = NewManagerForFirstStageMount(test_device);
 
     ASSERT_TRUE(new_sm->HandleImminentDataWipe());
     // Manually mount metadata so that we can call GetUpdateState() below.
@@ -1639,7 +1672,7 @@
 
     // Now reboot into new slot.
     test_device = new TestDeviceInfo(fake_super, "_b");
-    auto init = SnapshotManager::NewForFirstStageMount(test_device);
+    auto init = NewManagerForFirstStageMount(test_device);
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
     // Verify that we are on the downgraded build.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
@@ -1657,6 +1690,8 @@
     SetSize(sys_, partition_size);
     AddOperation(sys_, data_size);
 
+    sys_->set_estimate_cow_size(partition_size + data_size);
+
     // Set hastree extents.
     sys_->mutable_hash_tree_data_extent()->set_start_block(0);
     sys_->mutable_hash_tree_data_extent()->set_num_blocks(data_size / block_size);
@@ -1685,7 +1720,7 @@
     ASSERT_TRUE(UnmapAll());
 
     // After reboot, init does first stage mount.
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
@@ -1697,6 +1732,10 @@
 
 // Test for overflow bit after update
 TEST_F(SnapshotUpdateTest, Overflow) {
+    if (IsCompressionEnabled()) {
+        GTEST_SKIP() << "No overflow bit set for userspace COWs";
+    }
+
     const auto actual_write_size = GetSize(sys_);
     const auto declared_write_size = actual_write_size - 1_MiB;
 
@@ -1724,12 +1763,15 @@
     auto userdata = std::make_unique<LowSpaceUserdata>();
     ASSERT_TRUE(userdata->Init(kMaxFree));
 
-    // Grow all partitions to 5_MiB, total 15_MiB. This requires 15 MiB of CoW space. After
-    // using the empty space in super (< 1 MiB), it uses at least 14 MiB of /userdata space.
-    constexpr uint64_t partition_size = 5_MiB;
+    // Grow all partitions to 10_MiB, total 30_MiB. This requires 30 MiB of CoW space. After
+    // using the empty space in super (< 1 MiB), it uses 30 MiB of /userdata space.
+    constexpr uint64_t partition_size = 10_MiB;
     SetSize(sys_, partition_size);
     SetSize(vnd_, partition_size);
     SetSize(prd_, partition_size);
+    sys_->set_estimate_cow_size(partition_size);
+    vnd_->set_estimate_cow_size(partition_size);
+    prd_->set_estimate_cow_size(partition_size);
 
     AddOperationForPartitions();
 
@@ -1739,7 +1781,7 @@
     ASSERT_FALSE(res);
     ASSERT_EQ(Return::ErrorCode::NO_SPACE, res.error_code());
     ASSERT_GE(res.required_size(), 14_MiB);
-    ASSERT_LT(res.required_size(), 15_MiB);
+    ASSERT_LT(res.required_size(), 40_MiB);
 }
 
 class AutoKill final {
@@ -1773,7 +1815,7 @@
     ASSERT_TRUE(sm->FinishedSnapshotWrites(false));
     ASSERT_TRUE(UnmapAll());
 
-    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    auto init = NewManagerForFirstStageMount("_b");
     ASSERT_NE(init, nullptr);
 
     ASSERT_TRUE(init->EnsureSnapuserdConnected());
@@ -1785,7 +1827,7 @@
     ASSERT_EQ(access("/dev/dm-user/sys_b-user-cow-init", F_OK), 0);
     ASSERT_EQ(access("/dev/dm-user/sys_b-user-cow", F_OK), -1);
 
-    ASSERT_TRUE(init->PerformSecondStageTransition());
+    ASSERT_TRUE(init->PerformInitTransition(SnapshotManager::InitTransition::SECOND_STAGE));
 
     // The control device should have been renamed.
     ASSERT_TRUE(android::fs_mgr::WaitForFileDeleted("/dev/dm-user/sys_b-user-cow-init", 10s));
@@ -1887,8 +1929,7 @@
     ASSERT_TRUE(UnmapAll());
 
     // Simulate reboot. After reboot, init does first stage mount.
-    auto init = SnapshotManager::NewForFirstStageMount(
-            new TestDeviceInfo(fake_super, flashed_slot_suffix));
+    auto init = NewManagerForFirstStageMount(flashed_slot_suffix);
     ASSERT_NE(init, nullptr);
 
     if (flashed_slot && after_merge) {
diff --git a/fs_mgr/libsnapshot/snapuserd.cpp b/fs_mgr/libsnapshot/snapuserd.cpp
index 4f94806..573b6a5 100644
--- a/fs_mgr/libsnapshot/snapuserd.cpp
+++ b/fs_mgr/libsnapshot/snapuserd.cpp
@@ -129,88 +129,126 @@
     return true;
 }
 
-/*
- * Read the data of size bytes from a given chunk.
- *
- * Kernel can potentially merge the blocks if the
- * successive chunks are contiguous. For chunk size of 8,
- * there can be 256 disk exceptions; and if
- * all 256 disk exceptions are contiguous, kernel can merge
- * them into a single IO.
- *
- * Since each chunk in the disk exception
- * mapping represents a 4k block, kernel can potentially
- * issue 256*4k = 1M IO in one shot.
- *
- * Even though kernel assumes that the blocks are
- * contiguous, we need to split the 1M IO into 4k chunks
- * as each operation represents 4k and it can either be:
- *
- * 1: Replace operation
- * 2: Copy operation
- * 3: Zero operation
- *
- */
-bool Snapuserd::ReadData(chunk_t chunk, size_t size) {
-    size_t read_size = size;
-    bool ret = true;
-    chunk_t chunk_key = chunk;
+bool Snapuserd::ProcessCowOp(const CowOperation* cow_op) {
+    CHECK(cow_op != nullptr);
 
-    if (!((read_size & (BLOCK_SIZE - 1)) == 0)) {
-        SNAP_LOG(ERROR) << "ReadData - unaligned read_size: " << read_size;
-        return false;
+    switch (cow_op->type) {
+        case kCowReplaceOp: {
+            return ProcessReplaceOp(cow_op);
+        }
+
+        case kCowZeroOp: {
+            return ProcessZeroOp();
+        }
+
+        case kCowCopyOp: {
+            return ProcessCopyOp(cow_op);
+        }
+
+        default: {
+            SNAP_LOG(ERROR) << "Unknown operation-type found: " << cow_op->type;
+        }
+    }
+    return false;
+}
+
+int Snapuserd::ReadUnalignedSector(sector_t sector, size_t size,
+                                   std::map<sector_t, const CowOperation*>::iterator& it) {
+    size_t skip_sector_size = 0;
+
+    SNAP_LOG(DEBUG) << "ReadUnalignedSector: sector " << sector << " size: " << size
+                    << " Aligned sector: " << it->second;
+
+    if (!ProcessCowOp(it->second)) {
+        SNAP_LOG(ERROR) << "ReadUnalignedSector: " << sector << " failed";
+        return -1;
     }
 
-    while (read_size > 0) {
-        const CowOperation* cow_op = chunk_map_[chunk_key];
-        CHECK(cow_op != nullptr);
+    int num_sectors_skip = sector - it->first;
 
-        switch (cow_op->type) {
-            case kCowReplaceOp: {
-                ret = ProcessReplaceOp(cow_op);
-                break;
-            }
+    if (num_sectors_skip > 0) {
+        skip_sector_size = num_sectors_skip << SECTOR_SHIFT;
+        char* buffer = reinterpret_cast<char*>(bufsink_.GetBufPtr());
+        struct dm_user_message* msg = (struct dm_user_message*)(&(buffer[0]));
 
-            case kCowZeroOp: {
-                ret = ProcessZeroOp();
-                break;
-            }
+        memmove(msg->payload.buf, (char*)msg->payload.buf + skip_sector_size,
+                (BLOCK_SIZE - skip_sector_size));
+    }
 
-            case kCowCopyOp: {
-                ret = ProcessCopyOp(cow_op);
-                break;
-            }
+    bufsink_.ResetBufferOffset();
+    return std::min(size, (BLOCK_SIZE - skip_sector_size));
+}
 
-            default: {
-                SNAP_LOG(ERROR) << "Unknown operation-type found: " << cow_op->type;
-                ret = false;
-                break;
-            }
+/*
+ * Read the data for a given COW Operation.
+ *
+ * Kernel can issue IO at a sector granularity.
+ * Hence, an IO may end up with reading partial
+ * data from a COW operation or we may also
+ * end up with interspersed request between
+ * two COW operations.
+ *
+ */
+int Snapuserd::ReadData(sector_t sector, size_t size) {
+    /*
+     * chunk_map stores COW operation at 4k granularity.
+     * If the requested IO with the sector falls on the 4k
+     * boundary, then we can read the COW op directly without
+     * any issue.
+     *
+     * However, if the requested sector is not 4K aligned,
+     * then we will have the find the nearest COW operation
+     * and chop the 4K block to fetch the requested sector.
+     */
+    std::map<sector_t, const CowOperation*>::iterator it = chunk_map_.find(sector);
+    if (it == chunk_map_.end()) {
+        it = chunk_map_.lower_bound(sector);
+        if (it != chunk_map_.begin()) {
+            --it;
         }
 
-        if (!ret) {
-            SNAP_LOG(ERROR) << "ReadData failed for operation: " << cow_op->type;
-            return false;
-        }
+        /*
+         * If the IO is spanned between two COW operations,
+         * split the IO into two parts:
+         *
+         * 1: Read the first part from the single COW op
+         * 2: Read the second part from the next COW op.
+         *
+         * Ex: Let's say we have a 1024 Bytes IO request.
+         *
+         * 0       COW OP-1  4096     COW OP-2  8192
+         * |******************|*******************|
+         *              |*****|*****|
+         *           3584           4608
+         *              <- 1024B - >
+         *
+         * We have two COW operations which are 4k blocks.
+         * The IO is requested for 1024 Bytes which are spanned
+         * between two COW operations. We will split this IO
+         * into two parts:
+         *
+         * 1: IO of size 512B from offset 3584 bytes (COW OP-1)
+         * 2: IO of size 512B from offset 4096 bytes (COW OP-2)
+         */
+        return ReadUnalignedSector(sector, size, it);
+    }
 
+    int num_ops = DIV_ROUND_UP(size, BLOCK_SIZE);
+    while (num_ops) {
+        if (!ProcessCowOp(it->second)) {
+            return -1;
+        }
+        num_ops -= 1;
+        it++;
         // Update the buffer offset
         bufsink_.UpdateBufferOffset(BLOCK_SIZE);
 
-        read_size -= BLOCK_SIZE;
-
-        // Start iterating the chunk incrementally; Since while
-        // constructing the metadata, we know that the chunk IDs
-        // are contiguous
-        chunk_key += 1;
-
-        if (cow_op->type == kCowCopyOp) {
-            CHECK(read_size == 0);
-        }
+        SNAP_LOG(DEBUG) << "ReadData at sector: " << sector << " size: " << size;
     }
 
     // Reset the buffer offset
     bufsink_.ResetBufferOffset();
-    return ret;
+    return size;
 }
 
 /*
@@ -261,9 +299,7 @@
     if (divresult.quot < vec_.size()) {
         size = exceptions_per_area_ * sizeof(struct disk_exception);
 
-        if (read_size > size) {
-            return false;
-        }
+        CHECK(read_size == size);
 
         void* buffer = bufsink_.GetPayloadBuffer(size);
         CHECK(buffer != nullptr);
@@ -329,7 +365,7 @@
         if (cow_de->new_chunk != 0) {
             merged_ops_cur_iter += 1;
             offset += sizeof(struct disk_exception);
-            const CowOperation* cow_op = chunk_map_[cow_de->new_chunk];
+            const CowOperation* cow_op = chunk_map_[ChunkToSector(cow_de->new_chunk)];
             CHECK(cow_op != nullptr);
             CHECK(cow_op->new_block == cow_de->old_chunk);
             if (cow_op->type == kCowCopyOp) {
@@ -563,7 +599,7 @@
         SNAP_LOG(DEBUG) << "Old-chunk: " << de->old_chunk << "New-chunk: " << de->new_chunk;
 
         // Store operation pointer.
-        chunk_map_[data_chunk_id] = cow_op;
+        chunk_map_[ChunkToSector(data_chunk_id)] = cow_op;
         num_ops += 1;
         offset += sizeof(struct disk_exception);
         cowop_riter_->Next();
@@ -680,6 +716,126 @@
     return true;
 }
 
+bool Snapuserd::DmuserWriteRequest() {
+    struct dm_user_header* header = bufsink_.GetHeaderPtr();
+
+    // device mapper has the capability to allow
+    // targets to flush the cache when writes are completed. This
+    // is controlled by each target by a flag "flush_supported".
+    // This flag is set by dm-user. When flush is supported,
+    // a number of zero-length bio's will be submitted to
+    // the target for the purpose of flushing cache. It is the
+    // responsibility of the target driver - which is dm-user in this
+    // case, to remap these bio's to the underlying device. Since,
+    // there is no underlying device for dm-user, this zero length
+    // bio's gets routed to daemon.
+    //
+    // Flush operations are generated post merge by dm-snap by having
+    // REQ_PREFLUSH flag set. Snapuser daemon doesn't have anything
+    // to flush per se; hence, just respond back with a success message.
+    if (header->sector == 0) {
+        CHECK(header->len == 0);
+        header->type = DM_USER_RESP_SUCCESS;
+        if (!WriteDmUserPayload(0)) {
+            return false;
+        }
+        return true;
+    }
+
+    size_t remaining_size = header->len;
+    size_t read_size = std::min(PAYLOAD_SIZE, remaining_size);
+    CHECK(read_size == BLOCK_SIZE);
+
+    CHECK(header->sector > 0);
+    chunk_t chunk = SectorToChunk(header->sector);
+    CHECK(chunk_map_.find(header->sector) == chunk_map_.end());
+
+    void* buffer = bufsink_.GetPayloadBuffer(read_size);
+    CHECK(buffer != nullptr);
+    header->type = DM_USER_RESP_SUCCESS;
+
+    if (!ReadDmUserPayload(buffer, read_size)) {
+        SNAP_LOG(ERROR) << "ReadDmUserPayload failed for chunk id: " << chunk
+                        << "Sector: " << header->sector;
+        header->type = DM_USER_RESP_ERROR;
+    }
+
+    if (header->type == DM_USER_RESP_SUCCESS && !ProcessMergeComplete(chunk, buffer)) {
+        SNAP_LOG(ERROR) << "ProcessMergeComplete failed for chunk id: " << chunk
+                        << "Sector: " << header->sector;
+        header->type = DM_USER_RESP_ERROR;
+    } else {
+        SNAP_LOG(DEBUG) << "ProcessMergeComplete success for chunk id: " << chunk
+                        << "Sector: " << header->sector;
+    }
+
+    if (!WriteDmUserPayload(0)) {
+        return false;
+    }
+
+    return true;
+}
+
+bool Snapuserd::DmuserReadRequest() {
+    struct dm_user_header* header = bufsink_.GetHeaderPtr();
+    size_t remaining_size = header->len;
+    loff_t offset = 0;
+    sector_t sector = header->sector;
+    do {
+        size_t read_size = std::min(PAYLOAD_SIZE, remaining_size);
+
+        int ret = read_size;
+        header->type = DM_USER_RESP_SUCCESS;
+        chunk_t chunk = SectorToChunk(header->sector);
+
+        // Request to sector 0 is always for kernel
+        // representation of COW header. This IO should be only
+        // once during dm-snapshot device creation. We should
+        // never see multiple IO requests. Additionally this IO
+        // will always be a single 4k.
+        if (header->sector == 0) {
+            CHECK(metadata_read_done_ == true);
+            CHECK(read_size == BLOCK_SIZE);
+            ConstructKernelCowHeader();
+            SNAP_LOG(DEBUG) << "Kernel header constructed";
+        } else {
+            if (!offset && (read_size == BLOCK_SIZE) &&
+                chunk_map_.find(header->sector) == chunk_map_.end()) {
+                if (!ReadDiskExceptions(chunk, read_size)) {
+                    SNAP_LOG(ERROR) << "ReadDiskExceptions failed for chunk id: " << chunk
+                                    << "Sector: " << header->sector;
+                    header->type = DM_USER_RESP_ERROR;
+                } else {
+                    SNAP_LOG(DEBUG) << "ReadDiskExceptions success for chunk id: " << chunk
+                                    << "Sector: " << header->sector;
+                }
+            } else {
+                chunk_t num_sectors_read = (offset >> SECTOR_SHIFT);
+                ret = ReadData(sector + num_sectors_read, read_size);
+                if (ret < 0) {
+                    SNAP_LOG(ERROR) << "ReadData failed for chunk id: " << chunk
+                                    << "Sector: " << header->sector;
+                    header->type = DM_USER_RESP_ERROR;
+                } else {
+                    SNAP_LOG(DEBUG) << "ReadData success for chunk id: " << chunk
+                                    << "Sector: " << header->sector;
+                }
+            }
+        }
+
+        // Daemon will not be terminated if there is any error. We will
+        // just send the error back to dm-user.
+        if (!WriteDmUserPayload(ret)) {
+            return false;
+        }
+
+        remaining_size -= ret;
+        offset += ret;
+    } while (remaining_size > 0);
+
+    return true;
+}
+
 bool Snapuserd::Run() {
     struct dm_user_header* header = bufsink_.GetHeaderPtr();
 
@@ -698,122 +854,16 @@
 
     switch (header->type) {
         case DM_USER_REQ_MAP_READ: {
-            size_t remaining_size = header->len;
-            loff_t offset = 0;
-            do {
-                size_t read_size = std::min(PAYLOAD_SIZE, remaining_size);
-                header->type = DM_USER_RESP_SUCCESS;
-
-                // Request to sector 0 is always for kernel
-                // representation of COW header. This IO should be only
-                // once during dm-snapshot device creation. We should
-                // never see multiple IO requests. Additionally this IO
-                // will always be a single 4k.
-                if (header->sector == 0) {
-                    CHECK(metadata_read_done_ == true);
-                    CHECK(read_size == BLOCK_SIZE);
-                    ConstructKernelCowHeader();
-                    SNAP_LOG(DEBUG) << "Kernel header constructed";
-                } else {
-                    // Convert the sector number to a chunk ID.
-                    //
-                    // Check if the chunk ID represents a metadata
-                    // page. If the chunk ID is not found in the
-                    // vector, then it points to a metadata page.
-                    chunk_t chunk = SectorToChunk(header->sector);
-
-                    if (chunk_map_.find(chunk) == chunk_map_.end()) {
-                        if (!ReadDiskExceptions(chunk, read_size)) {
-                            SNAP_LOG(ERROR) << "ReadDiskExceptions failed for chunk id: " << chunk
-                                            << "Sector: " << header->sector;
-                            header->type = DM_USER_RESP_ERROR;
-                        } else {
-                            SNAP_LOG(DEBUG) << "ReadDiskExceptions success for chunk id: " << chunk
-                                            << "Sector: " << header->sector;
-                        }
-                    } else {
-                        SNAP_LOG(DEBUG) << "ReadData: chunk: " << chunk << " len: " << header->len
-                                        << " read_size: " << read_size << " offset: " << offset;
-                        chunk_t num_chunks_read = (offset >> BLOCK_SHIFT);
-                        if (!ReadData(chunk + num_chunks_read, read_size)) {
-                            SNAP_LOG(ERROR) << "ReadData failed for chunk id: " << chunk
-                                            << "Sector: " << header->sector;
-                            header->type = DM_USER_RESP_ERROR;
-                        } else {
-                            SNAP_LOG(DEBUG) << "ReadData success for chunk id: " << chunk
-                                            << "Sector: " << header->sector;
-                        }
-                    }
-                }
-
-                // Daemon will not be terminated if there is any error. We will
-                // just send the error back to dm-user.
-                if (!WriteDmUserPayload(read_size)) {
-                    return false;
-                }
-
-                remaining_size -= read_size;
-                offset += read_size;
-            } while (remaining_size);
-
+            if (!DmuserReadRequest()) {
+                return false;
+            }
             break;
         }
 
         case DM_USER_REQ_MAP_WRITE: {
-            // device mapper has the capability to allow
-            // targets to flush the cache when writes are completed. This
-            // is controlled by each target by a flag "flush_supported".
-            // This flag is set by dm-user. When flush is supported,
-            // a number of zero-length bio's will be submitted to
-            // the target for the purpose of flushing cache. It is the
-            // responsibility of the target driver - which is dm-user in this
-            // case, to remap these bio's to the underlying device. Since,
-            // there is no underlying device for dm-user, this zero length
-            // bio's gets routed to daemon.
-            //
-            // Flush operations are generated post merge by dm-snap by having
-            // REQ_PREFLUSH flag set. Snapuser daemon doesn't have anything
-            // to flush per se; hence, just respond back with a success message.
-            if (header->sector == 0) {
-                CHECK(header->len == 0);
-                header->type = DM_USER_RESP_SUCCESS;
-                if (!WriteDmUserPayload(0)) {
-                    return false;
-                }
-                break;
-            }
-
-            size_t remaining_size = header->len;
-            size_t read_size = std::min(PAYLOAD_SIZE, remaining_size);
-            CHECK(read_size == BLOCK_SIZE);
-
-            CHECK(header->sector > 0);
-            chunk_t chunk = SectorToChunk(header->sector);
-            CHECK(chunk_map_.find(chunk) == chunk_map_.end());
-
-            void* buffer = bufsink_.GetPayloadBuffer(read_size);
-            CHECK(buffer != nullptr);
-            header->type = DM_USER_RESP_SUCCESS;
-
-            if (!ReadDmUserPayload(buffer, read_size)) {
-                SNAP_LOG(ERROR) << "ReadDmUserPayload failed for chunk id: " << chunk
-                                << "Sector: " << header->sector;
-                header->type = DM_USER_RESP_ERROR;
-            }
-
-            if (header->type == DM_USER_RESP_SUCCESS && !ProcessMergeComplete(chunk, buffer)) {
-                SNAP_LOG(ERROR) << "ProcessMergeComplete failed for chunk id: " << chunk
-                                << "Sector: " << header->sector;
-                header->type = DM_USER_RESP_ERROR;
-            } else {
-                SNAP_LOG(DEBUG) << "ProcessMergeComplete success for chunk id: " << chunk
-                                << "Sector: " << header->sector;
-            }
-
-            if (!WriteDmUserPayload(0)) {
+            if (!DmuserWriteRequest()) {
                 return false;
             }
-
             break;
         }
     }
diff --git a/fs_mgr/libsnapshot/snapuserd.h b/fs_mgr/libsnapshot/snapuserd.h
index eec6d45..c01fee3 100644
--- a/fs_mgr/libsnapshot/snapuserd.h
+++ b/fs_mgr/libsnapshot/snapuserd.h
@@ -22,9 +22,9 @@
 #include <cstring>
 #include <iostream>
 #include <limits>
+#include <map>
 #include <string>
 #include <thread>
-#include <unordered_map>
 #include <vector>
 
 #include <android-base/file.h>
@@ -72,6 +72,9 @@
     bool IsAttached() const { return ctrl_fd_ >= 0; }
 
   private:
+    bool DmuserReadRequest();
+    bool DmuserWriteRequest();
+
     bool ReadDmUserHeader();
     bool ReadDmUserPayload(void* buffer, size_t size);
     bool WriteDmUserPayload(size_t size);
@@ -79,10 +82,13 @@
     bool ReadMetadata();
     bool ZerofillDiskExceptions(size_t read_size);
     bool ReadDiskExceptions(chunk_t chunk, size_t size);
-    bool ReadData(chunk_t chunk, size_t size);
+    int ReadUnalignedSector(sector_t sector, size_t size,
+                            std::map<sector_t, const CowOperation*>::iterator& it);
+    int ReadData(sector_t sector, size_t size);
     bool IsChunkIdMetadata(chunk_t chunk);
     chunk_t GetNextAllocatableChunkId(chunk_t chunk_id);
 
+    bool ProcessCowOp(const CowOperation* cow_op);
     bool ProcessReplaceOp(const CowOperation* cow_op);
     bool ProcessCopyOp(const CowOperation* cow_op);
     bool ProcessZeroOp();
@@ -94,6 +100,7 @@
     bool ProcessMergeComplete(chunk_t chunk, void* buffer);
     sector_t ChunkToSector(chunk_t chunk) { return chunk << CHUNK_SHIFT; }
     chunk_t SectorToChunk(sector_t sector) { return sector >> CHUNK_SHIFT; }
+    bool IsBlockAligned(int read_size) { return ((read_size & (BLOCK_SIZE - 1)) == 0); }
 
     std::string cow_device_;
     std::string backing_store_device_;
@@ -116,9 +123,15 @@
     // mapping of old-chunk to new-chunk
     std::vector<std::unique_ptr<uint8_t[]>> vec_;
 
-    // Key - Chunk ID
+    // Key - Sector
     // Value - cow operation
-    std::unordered_map<chunk_t, const CowOperation*> chunk_map_;
+    //
+    // chunk_map stores the pseudo mapping of sector
+    // to COW operations. Each COW op is 4k; however,
+    // we can get a read request which are as small
+    // as 512 bytes. Hence, we need to binary search
+    // in the chunk_map to find the nearest COW op.
+    std::map<sector_t, const CowOperation*> chunk_map_;
 
     bool metadata_read_done_ = false;
     BufferSink bufsink_;
diff --git a/fs_mgr/libsnapshot/snapuserd_server.cpp b/fs_mgr/libsnapshot/snapuserd_server.cpp
index 8351155..38abaec 100644
--- a/fs_mgr/libsnapshot/snapuserd_server.cpp
+++ b/fs_mgr/libsnapshot/snapuserd_server.cpp
@@ -77,9 +77,8 @@
     JoinAllThreads();
 }
 
-const std::string& DmUserHandler::GetMiscName() const {
-    return snapuserd_->GetMiscName();
-}
+DmUserHandler::DmUserHandler(std::unique_ptr<Snapuserd>&& snapuserd)
+    : snapuserd_(std::move(snapuserd)), misc_name_(snapuserd_->GetMiscName()) {}
 
 bool SnapuserdServer::Sendmsg(android::base::borrowed_fd fd, const std::string& msg) {
     ssize_t ret = TEMP_FAILURE_RETRY(send(fd.get(), msg.data(), msg.size(), 0));
@@ -148,7 +147,7 @@
                 LOG(ERROR) << "Could not find handler: " << out[1];
                 return Sendmsg(fd, "fail");
             }
-            if ((*iter)->snapuserd()->IsAttached()) {
+            if (!(*iter)->snapuserd() || (*iter)->snapuserd()->IsAttached()) {
                 LOG(ERROR) << "Tried to re-attach control device: " << out[1];
                 return Sendmsg(fd, "fail");
             }
@@ -185,7 +184,7 @@
                 LOG(ERROR) << "Malformed delete message, " << out.size() << " parts";
                 return Sendmsg(fd, "fail");
             }
-            if (!RemoveHandler(out[1], true)) {
+            if (!RemoveAndJoinHandler(out[1])) {
                 return Sendmsg(fd, "fail");
             }
             return Sendmsg(fd, "success");
@@ -203,20 +202,38 @@
 }
 
 void SnapuserdServer::RunThread(std::shared_ptr<DmUserHandler> handler) {
-    LOG(INFO) << "Entering thread for handler: " << handler->GetMiscName();
+    LOG(INFO) << "Entering thread for handler: " << handler->misc_name();
 
     while (!StopRequested()) {
         if (!handler->snapuserd()->Run()) {
-            LOG(INFO) << "Snapuserd: Thread terminating";
             break;
         }
     }
 
-    LOG(INFO) << "Exiting thread for handler: " << handler->GetMiscName();
+    auto misc_name = handler->misc_name();
+    LOG(INFO) << "Handler thread about to exit: " << misc_name;
 
-    // If the main thread called RemoveHandler, the handler was already removed
-    // from within the lock, and calling RemoveHandler again has no effect.
-    RemoveHandler(handler->GetMiscName(), false);
+    {
+        std::lock_guard<std::mutex> lock(lock_);
+        auto iter = FindHandler(&lock, handler->misc_name());
+        if (iter == dm_users_.end()) {
+            // RemoveAndJoinHandler() already removed us from the list, and is
+            // now waiting on a join(), so just return.
+            LOG(INFO) << "Exiting handler thread to allow for join: " << misc_name;
+            return;
+        }
+
+        LOG(INFO) << "Exiting handler thread and freeing resources: " << misc_name;
+
+        if (handler->snapuserd()->IsAttached()) {
+            handler->thread().detach();
+        }
+
+        // Important: free resources within the lock. This ensures that if
+        // WaitForDelete() is called, the handler is either in the list, or
+        // it's not and its resources are guaranteed to be freed.
+        handler->FreeResources();
+    }
 }
 
 bool SnapuserdServer::Start(const std::string& socketname) {
@@ -351,7 +368,7 @@
     CHECK(!handler->snapuserd()->IsAttached());
 
     if (!handler->snapuserd()->InitBackingAndControlDevice()) {
-        LOG(ERROR) << "Failed to initialize control device: " << handler->GetMiscName();
+        LOG(ERROR) << "Failed to initialize control device: " << handler->misc_name();
         return false;
     }
 
@@ -364,14 +381,14 @@
     CHECK(proof_of_lock);
 
     for (auto iter = dm_users_.begin(); iter != dm_users_.end(); iter++) {
-        if ((*iter)->GetMiscName() == misc_name) {
+        if ((*iter)->misc_name() == misc_name) {
             return iter;
         }
     }
     return dm_users_.end();
 }
 
-bool SnapuserdServer::RemoveHandler(const std::string& misc_name, bool wait) {
+bool SnapuserdServer::RemoveAndJoinHandler(const std::string& misc_name) {
     std::shared_ptr<DmUserHandler> handler;
     {
         std::lock_guard<std::mutex> lock(lock_);
@@ -386,10 +403,8 @@
     }
 
     auto& th = handler->thread();
-    if (th.joinable() && wait) {
+    if (th.joinable()) {
         th.join();
-    } else if (handler->snapuserd()->IsAttached()) {
-        th.detach();
     }
     return true;
 }
diff --git a/fs_mgr/libsnapshot/snapuserd_server.h b/fs_mgr/libsnapshot/snapuserd_server.h
index 01e2365..7cbc2de 100644
--- a/fs_mgr/libsnapshot/snapuserd_server.h
+++ b/fs_mgr/libsnapshot/snapuserd_server.h
@@ -46,18 +46,19 @@
 };
 
 class DmUserHandler {
-  private:
-    std::thread thread_;
-    std::unique_ptr<Snapuserd> snapuserd_;
-
   public:
-    explicit DmUserHandler(std::unique_ptr<Snapuserd>&& snapuserd)
-        : snapuserd_(std::move(snapuserd)) {}
+    explicit DmUserHandler(std::unique_ptr<Snapuserd>&& snapuserd);
 
+    void FreeResources() { snapuserd_ = nullptr; }
     const std::unique_ptr<Snapuserd>& snapuserd() const { return snapuserd_; }
     std::thread& thread() { return thread_; }
 
-    const std::string& GetMiscName() const;
+    const std::string& misc_name() const { return misc_name_; }
+
+  private:
+    std::thread thread_;
+    std::unique_ptr<Snapuserd> snapuserd_;
+    std::string misc_name_;
 };
 
 class Stoppable {
@@ -71,8 +72,9 @@
 
     bool StopRequested() {
         // checks if value in future object is available
-        if (futureObj_.wait_for(std::chrono::milliseconds(0)) == std::future_status::timeout)
+        if (futureObj_.wait_for(std::chrono::milliseconds(0)) == std::future_status::timeout) {
             return false;
+        }
         return true;
     }
     // Request the thread to stop by setting value in promise object
@@ -98,7 +100,7 @@
     bool Receivemsg(android::base::borrowed_fd fd, const std::string& str);
 
     void ShutdownThreads();
-    bool RemoveHandler(const std::string& control_device, bool wait);
+    bool RemoveAndJoinHandler(const std::string& control_device);
     DaemonOperations Resolveop(std::string& input);
     std::string GetDaemonStatus();
     void Parsemsg(std::string const& msg, const char delim, std::vector<std::string>& out);
diff --git a/gatekeeperd/Android.bp b/gatekeeperd/Android.bp
index 27a6452..2d9a820 100644
--- a/gatekeeperd/Android.bp
+++ b/gatekeeperd/Android.bp
@@ -28,6 +28,7 @@
 
     shared_libs: [
         "libbinder",
+        "libbinder_ndk",
         "libgatekeeper",
         "libgsi",
         "liblog",
@@ -40,6 +41,8 @@
         "libhidlbase",
         "android.hardware.gatekeeper@1.0",
         "libgatekeeper_aidl",
+        "android.hardware.security.keymint-unstable-ndk_platform",
+        "android.security.authorization-ndk_platform",
     ],
 
     static_libs: ["libscrypt_static"],
diff --git a/gatekeeperd/gatekeeperd.cpp b/gatekeeperd/gatekeeperd.cpp
index b982dbc..941f8c2 100644
--- a/gatekeeperd/gatekeeperd.cpp
+++ b/gatekeeperd/gatekeeperd.cpp
@@ -19,42 +19,45 @@
 #include <android/service/gatekeeper/BnGateKeeperService.h>
 #include <gatekeeper/GateKeeperResponse.h>
 
+#include <endian.h>
 #include <errno.h>
 #include <fcntl.h>
-#include <inttypes.h>
-#include <stdint.h>
 #include <unistd.h>
 #include <memory>
 
-#include <android/security/keystore/IKeystoreService.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
+#include <android/binder_ibinder.h>
+#include <android/binder_manager.h>
+#include <android/security/keystore/IKeystoreService.h>
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
 #include <binder/PermissionCache.h>
-#include <gatekeeper/password_handle.h> // for password_handle_t
-#include <hardware/gatekeeper.h>
+#include <gatekeeper/password_handle.h>  // for password_handle_t
 #include <hardware/hw_auth_token.h>
-#include <keystore/keystore.h> // For error code
 #include <keystore/keystore_return_types.h>
 #include <libgsi/libgsi.h>
 #include <log/log.h>
-#include <utils/Log.h>
 #include <utils/String16.h>
 
-#include <hidl/HidlSupport.h>
+#include <aidl/android/hardware/security/keymint/HardwareAuthToken.h>
+#include <aidl/android/security/authorization/IKeystoreAuthorization.h>
 #include <android/hardware/gatekeeper/1.0/IGatekeeper.h>
+#include <hidl/HidlSupport.h>
 
 using android::sp;
-using android::hardware::gatekeeper::V1_0::IGatekeeper;
-using android::hardware::gatekeeper::V1_0::GatekeeperStatusCode;
-using android::hardware::gatekeeper::V1_0::GatekeeperResponse;
 using android::hardware::Return;
+using android::hardware::gatekeeper::V1_0::GatekeeperResponse;
+using android::hardware::gatekeeper::V1_0::GatekeeperStatusCode;
+using android::hardware::gatekeeper::V1_0::IGatekeeper;
 
 using ::android::binder::Status;
 using ::android::service::gatekeeper::BnGateKeeperService;
 using GKResponse = ::android::service::gatekeeper::GateKeeperResponse;
 using GKResponseCode = ::android::service::gatekeeper::ResponseCode;
+using ::aidl::android::hardware::security::keymint::HardwareAuthenticatorType;
+using ::aidl::android::hardware::security::keymint::HardwareAuthToken;
+using ::aidl::android::security::authorization::IKeystoreAuthorization;
 
 namespace android {
 
@@ -62,7 +65,7 @@
 static const String16 DUMP_PERMISSION("android.permission.DUMP");
 
 class GateKeeperProxy : public BnGateKeeperService {
-public:
+  public:
     GateKeeperProxy() {
         clear_state_if_needed_done = false;
         hw_device = IGatekeeper::getService();
@@ -73,8 +76,7 @@
         }
     }
 
-    virtual ~GateKeeperProxy() {
-    }
+    virtual ~GateKeeperProxy() {}
 
     void store_sid(uint32_t userId, uint64_t sid) {
         char filename[21];
@@ -96,7 +98,7 @@
         if (mark_cold_boot() && !is_running_gsi) {
             ALOGI("cold boot: clearing state");
             if (hw_device) {
-                hw_device->deleteAllUsers([](const GatekeeperResponse &){});
+                hw_device->deleteAllUsers([](const GatekeeperResponse&) {});
             }
         }
 
@@ -104,7 +106,7 @@
     }
 
     bool mark_cold_boot() {
-        const char *filename = ".coldboot";
+        const char* filename = ".coldboot";
         if (access(filename, F_OK) == -1) {
             int fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR);
             if (fd < 0) {
@@ -299,7 +301,36 @@
 
         if (gkResponse->response_code() == GKResponseCode::OK) {
             if (gkResponse->payload().size() != 0) {
+                // try to connect to IKeystoreAuthorization AIDL service first.
+                AIBinder* authzAIBinder =
+                        AServiceManager_checkService("android.security.authorization");
+                ::ndk::SpAIBinder authzBinder(authzAIBinder);
+                auto authzService = IKeystoreAuthorization::fromBinder(authzBinder);
+                if (authzService) {
+                    if (gkResponse->payload().size() != sizeof(hw_auth_token_t)) {
+                        LOG(ERROR) << "Incorrect size of AuthToken payload.";
+                        return GK_ERROR;
+                    }
+
+                    const hw_auth_token_t* hwAuthToken =
+                            reinterpret_cast<const hw_auth_token_t*>(gkResponse->payload().data());
+                    HardwareAuthToken authToken;
+
+                    authToken.timestamp.milliSeconds = betoh64(hwAuthToken->timestamp);
+                    authToken.challenge = hwAuthToken->challenge;
+                    authToken.authenticatorId = hwAuthToken->authenticator_id;
+                    authToken.authenticatorType = static_cast<HardwareAuthenticatorType>(
+                            betoh32(hwAuthToken->authenticator_type));
+                    authToken.mac.assign(&hwAuthToken->hmac[0], &hwAuthToken->hmac[32]);
+                    auto result = authzService->addAuthToken(authToken);
+                    if (!result.isOk()) {
+                        LOG(ERROR) << "Failure in sending AuthToken to AuthorizationService.";
+                        return GK_ERROR;
+                    }
+                    AIBinder_decStrong(authzAIBinder);
+                }
                 sp<IServiceManager> sm = defaultServiceManager();
+
                 sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
                 sp<security::keystore::IKeystoreService> service =
                         interface_cast<security::keystore::IKeystoreService>(binder);
@@ -310,9 +341,12 @@
                     if (!binder_result.isOk() ||
                         !keystore::KeyStoreServiceReturnCode(result).isOk()) {
                         LOG(ERROR) << "Failure sending auth token to KeyStore: " << result;
+                        return GK_ERROR;
                     }
                 } else {
-                    LOG(ERROR) << "Cannot deliver auth token. Unable to communicate with Keystore.";
+                    LOG(ERROR) << "Cannot deliver auth token. Unable to communicate with "
+                                  "Keystore.";
+                    return GK_ERROR;
                 }
             }
 
@@ -366,23 +400,23 @@
         }
 
         if (hw_device == NULL) {
-            const char *result = "Device not available";
+            const char* result = "Device not available";
             write(fd, result, strlen(result) + 1);
         } else {
-            const char *result = "OK";
+            const char* result = "OK";
             write(fd, result, strlen(result) + 1);
         }
 
         return OK;
     }
 
-private:
+  private:
     sp<IGatekeeper> hw_device;
 
     bool clear_state_if_needed_done;
     bool is_running_gsi;
 };
-}// namespace android
+}  // namespace android
 
 int main(int argc, char* argv[]) {
     ALOGI("Starting gatekeeperd...");
diff --git a/healthd/Android.bp b/healthd/Android.bp
index b3de9c4..251a45b 100644
--- a/healthd/Android.bp
+++ b/healthd/Android.bp
@@ -62,29 +62,6 @@
     srcs: [
         "HealthServiceDefault.cpp",
     ],
-
-    overrides: [
-        "healthd",
-    ]
-}
-
-cc_binary {
-    name: "healthd",
-    defaults: ["android.hardware.health@2.0-service_defaults"],
-
-    init_rc: ["healthd.rc"],
-    srcs: [
-        "HealthServiceHealthd.cpp",
-    ],
-    local_include_dirs: ["include"],
-
-    shared_libs: [
-        "android.hardware.health@1.0",
-    ],
-
-    vintf_fragments: [
-        "manifest_healthd.xml"
-    ],
 }
 
 cc_library_static {
diff --git a/healthd/HealthServiceHealthd.cpp b/healthd/HealthServiceHealthd.cpp
deleted file mode 100644
index 5fd2597..0000000
--- a/healthd/HealthServiceHealthd.cpp
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * Copyright (C) 2017 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.
- */
-
-#define LOG_TAG "healthd"
-#include <android-base/logging.h>
-
-#include <android/hardware/health/1.0/IHealth.h>
-#include <android/hardware/health/1.0/types.h>
-#include <hal_conversion.h>
-#include <health2/service.h>
-#include <healthd/healthd.h>
-#include <hidl/HidlTransportSupport.h>
-
-using android::OK;
-using android::NAME_NOT_FOUND;
-using android::hardware::health::V1_0::HealthConfig;
-using android::hardware::health::V1_0::HealthInfo;
-using android::hardware::health::V1_0::Result;
-using android::hardware::health::V1_0::hal_conversion::convertFromHealthConfig;
-using android::hardware::health::V1_0::hal_conversion::convertToHealthConfig;
-using android::hardware::health::V1_0::hal_conversion::convertFromHealthInfo;
-using android::hardware::health::V1_0::hal_conversion::convertToHealthInfo;
-
-using IHealthLegacy = android::hardware::health::V1_0::IHealth;
-
-static android::sp<IHealthLegacy> gHealth_1_0;
-
-static int healthd_board_get_energy_counter(int64_t* energy) {
-    if (gHealth_1_0 == nullptr) {
-        return NAME_NOT_FOUND;
-    }
-
-    Result result = Result::NOT_SUPPORTED;
-    gHealth_1_0->energyCounter([energy, &result](Result ret, int64_t energyOut) {
-        result = ret;
-        *energy = energyOut;
-    });
-
-    return result == Result::SUCCESS ? OK : NAME_NOT_FOUND;
-}
-
-void healthd_board_init(struct healthd_config* config) {
-    gHealth_1_0 = IHealthLegacy::getService();
-
-    if (gHealth_1_0 == nullptr) {
-        return;
-    }
-
-    HealthConfig halConfig{};
-    convertToHealthConfig(config, halConfig);
-    gHealth_1_0->init(halConfig, [config](const auto& halConfigOut) {
-        convertFromHealthConfig(halConfigOut, config);
-        // always redirect energy counter queries
-        config->energyCounter = healthd_board_get_energy_counter;
-    });
-    LOG(INFO) << LOG_TAG << ": redirecting calls to 1.0 health HAL";
-}
-
-// TODO(b/68724651): Move this function into healthd_mode_service_2_0_battery_update
-// with logthis returned.
-int healthd_board_battery_update(struct android::BatteryProperties* props) {
-    int logthis = 0;
-
-    if (gHealth_1_0 == nullptr) {
-        return logthis;
-    }
-
-    HealthInfo info;
-    convertToHealthInfo(props, info);
-    gHealth_1_0->update(info, [props, &logthis](int32_t ret, const auto& infoOut) {
-        logthis = ret;
-        convertFromHealthInfo(infoOut, props);
-    });
-
-    return logthis;
-}
-
-int main() {
-    return health_service_main("backup");
-}
diff --git a/healthd/manifest_healthd.xml b/healthd/manifest_healthd.xml
deleted file mode 100644
index 097a7d8..0000000
--- a/healthd/manifest_healthd.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<manifest version="1.0" type="framework">
-    <hal>
-        <name>android.hardware.health</name>
-        <transport>hwbinder</transport>
-        <version>2.0</version>
-        <interface>
-            <name>IHealth</name>
-            <instance>backup</instance>
-        </interface>
-    </hal>
-</manifest>
diff --git a/init/Android.bp b/init/Android.bp
index 19ba21b..cd295cf 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -60,6 +60,7 @@
     "selabel.cpp",
     "selinux.cpp",
     "sigchld_handler.cpp",
+    "snapuserd_transition.cpp",
     "switch_root.cpp",
     "uevent_listener.cpp",
     "ueventd.cpp",
diff --git a/init/Android.mk b/init/Android.mk
index c881e2f..561d641 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -57,6 +57,8 @@
     reboot_utils.cpp \
     selabel.cpp \
     selinux.cpp \
+    service_utils.cpp \
+    snapuserd_transition.cpp \
     switch_root.cpp \
     uevent_listener.cpp \
     util.cpp \
diff --git a/init/block_dev_initializer.h b/init/block_dev_initializer.h
index 79fe4ec..ec39ce0 100644
--- a/init/block_dev_initializer.h
+++ b/init/block_dev_initializer.h
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#pragma once
+
 #include <memory>
 #include <set>
 #include <string>
diff --git a/init/first_stage_init.cpp b/init/first_stage_init.cpp
index 0949fc5..6954c03 100644
--- a/init/first_stage_init.cpp
+++ b/init/first_stage_init.cpp
@@ -42,6 +42,7 @@
 #include "first_stage_mount.h"
 #include "reboot_utils.h"
 #include "second_stage_resources.h"
+#include "snapuserd_transition.h"
 #include "switch_root.h"
 #include "util.h"
 
@@ -90,6 +91,12 @@
                     }
                 }
             }
+        } else if (de->d_type == DT_REG) {
+            // Do not free snapuserd if we will need the ramdisk copy during the
+            // selinux transition.
+            if (de->d_name == "snapuserd"s && IsFirstStageSnapuserdRunning()) {
+                continue;
+            }
         }
         unlinkat(dfd, de->d_name, is_dir ? AT_REMOVEDIR : 0);
     }
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index a0511cc..7c46281 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -44,6 +44,7 @@
 
 #include "block_dev_initializer.h"
 #include "devices.h"
+#include "snapuserd_transition.h"
 #include "switch_root.h"
 #include "uevent.h"
 #include "uevent_listener.h"
@@ -87,6 +88,7 @@
   protected:
     bool InitRequiredDevices(std::set<std::string> devices);
     bool CreateLogicalPartitions();
+    bool CreateSnapshotPartitions(android::snapshot::SnapshotManager* sm);
     bool MountPartition(const Fstab::iterator& begin, bool erase_same_mounts,
                         Fstab::iterator* end = nullptr);
 
@@ -109,6 +111,7 @@
 
     bool need_dm_verity_;
     bool dsu_not_on_userdata_ = false;
+    bool use_snapuserd_ = false;
 
     Fstab fstab_;
     // The super path is only set after InitDevices, and is invalid before.
@@ -338,21 +341,7 @@
             return false;
         }
         if (sm->NeedSnapshotsInFirstStageMount()) {
-            // When COW images are present for snapshots, they are stored on
-            // the data partition.
-            if (!InitRequiredDevices({"userdata"})) {
-                return false;
-            }
-            sm->SetUeventRegenCallback([this](const std::string& device) -> bool {
-                if (android::base::StartsWith(device, "/dev/block/dm-")) {
-                    return block_dev_init_.InitDmDevice(device);
-                }
-                if (android::base::StartsWith(device, "/dev/dm-user/")) {
-                    return block_dev_init_.InitDmUser(android::base::Basename(device));
-                }
-                return block_dev_init_.InitDevices({device});
-            });
-            return sm->CreateLogicalAndSnapshotPartitions(super_path_);
+            return CreateSnapshotPartitions(sm.get());
         }
     }
 
@@ -367,6 +356,37 @@
     return android::fs_mgr::CreateLogicalPartitions(*metadata.get(), super_path_);
 }
 
+bool FirstStageMount::CreateSnapshotPartitions(SnapshotManager* sm) {
+    // When COW images are present for snapshots, they are stored on
+    // the data partition.
+    if (!InitRequiredDevices({"userdata"})) {
+        return false;
+    }
+
+    use_snapuserd_ = sm->IsSnapuserdRequired();
+    if (use_snapuserd_) {
+        LaunchFirstStageSnapuserd();
+    }
+
+    sm->SetUeventRegenCallback([this](const std::string& device) -> bool {
+        if (android::base::StartsWith(device, "/dev/block/dm-")) {
+            return block_dev_init_.InitDmDevice(device);
+        }
+        if (android::base::StartsWith(device, "/dev/dm-user/")) {
+            return block_dev_init_.InitDmUser(android::base::Basename(device));
+        }
+        return block_dev_init_.InitDevices({device});
+    });
+    if (!sm->CreateLogicalAndSnapshotPartitions(super_path_)) {
+        return false;
+    }
+
+    if (use_snapuserd_) {
+        CleanupSnapuserdSocket();
+    }
+    return true;
+}
+
 bool FirstStageMount::MountPartition(const Fstab::iterator& begin, bool erase_same_mounts,
                                      Fstab::iterator* end) {
     // Sets end to begin + 1, so we can just return on failure below.
@@ -466,6 +486,10 @@
 
     if (system_partition == fstab_.end()) return true;
 
+    if (use_snapuserd_) {
+        SaveRamdiskPathToSnapuserd();
+    }
+
     if (MountPartition(system_partition, false /* erase_same_mounts */)) {
         if (dsu_not_on_userdata_ && fs_mgr_verity_is_check_at_most_once(*system_partition)) {
             LOG(ERROR) << "check_most_at_once forbidden on external media";
diff --git a/init/init.cpp b/init/init.cpp
index d1998a5..ca2d5da 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -79,6 +79,7 @@
 #include "service.h"
 #include "service_parser.h"
 #include "sigchld_handler.h"
+#include "snapuserd_transition.h"
 #include "subcontext.h"
 #include "system/core/init/property_service.pb.h"
 #include "util.h"
@@ -741,10 +742,15 @@
         return {};
     }
     svc->Start();
+    svc->SetShutdownCritical();
 
-    if (!sm->PerformSecondStageTransition()) {
+    if (!sm->PerformSecondStageInitTransition()) {
         LOG(FATAL) << "Failed to transition snapuserd to second-stage";
     }
+
+    if (auto pid = GetSnapuserdFirstStagePid()) {
+        KillFirstStageSnapuserd(pid.value());
+    }
     return {};
 }
 
@@ -872,6 +878,21 @@
     auto is_installed = android::gsi::IsGsiInstalled() ? "1" : "0";
     SetProperty(gsi::kGsiInstalledProp, is_installed);
 
+    /*
+     * For debug builds of S launching devices, init mounts debugfs for
+     * enabling vendor debug data collection setup at boot time. Init will unmount it on
+     * boot-complete after vendor code has performed the required initializations
+     * during boot. Dumpstate will then mount debugfs in order to read data
+     * from the same using the dumpstate HAL during bugreport creation.
+     * Dumpstate will also unmount debugfs after bugreport creation.
+     * first_api_level comparison is done here instead
+     * of init.rc since init.rc parser does not support >/< operators.
+     */
+    auto api_level = android::base::GetIntProperty("ro.product.first_api_level", 0);
+    bool is_debuggable = android::base::GetBoolProperty("ro.debuggable", false);
+    auto mount_debugfs = (is_debuggable && (api_level >= 31)) ? "1" : "0";
+    SetProperty("init.mount_debugfs", mount_debugfs);
+
     am.QueueBuiltinAction(SetupCgroupsAction, "SetupCgroups");
     am.QueueBuiltinAction(SetKptrRestrictAction, "SetKptrRestrict");
     am.QueueBuiltinAction(TestPerfEventSelinuxAction, "TestPerfEventSelinux");
diff --git a/init/property_service.cpp b/init/property_service.cpp
index e71c386..ce67386 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -890,6 +890,69 @@
     }
 }
 
+// If the ro.product.cpu.abilist* properties have not been explicitly
+// set, derive them from ro.${partition}.product.cpu.abilist* properties.
+static void property_initialize_ro_cpu_abilist() {
+    // From high to low priority.
+    const char* kAbilistSources[] = {
+            "product",
+            "odm",
+            "vendor",
+            "system",
+    };
+    const std::string EMPTY = "";
+    const char* kAbilistProp = "ro.product.cpu.abilist";
+    const char* kAbilist32Prop = "ro.product.cpu.abilist32";
+    const char* kAbilist64Prop = "ro.product.cpu.abilist64";
+
+    // If the properties are defined explicitly, just use them.
+    if (GetProperty(kAbilistProp, EMPTY) != EMPTY) {
+        return;
+    }
+
+    // Find the first source defining these properties by order.
+    std::string abilist32_prop_val;
+    std::string abilist64_prop_val;
+    for (const auto& source : kAbilistSources) {
+        const auto abilist32_prop = std::string("ro.") + source + ".product.cpu.abilist32";
+        const auto abilist64_prop = std::string("ro.") + source + ".product.cpu.abilist64";
+        abilist32_prop_val = GetProperty(abilist32_prop, EMPTY);
+        abilist64_prop_val = GetProperty(abilist64_prop, EMPTY);
+        // The properties could be empty on 32-bit-only or 64-bit-only devices,
+        // but we cannot identify a property is empty or undefined by GetProperty().
+        // So, we assume both of these 2 properties are empty as undefined.
+        if (abilist32_prop_val != EMPTY || abilist64_prop_val != EMPTY) {
+            break;
+        }
+    }
+
+    // Merge ABI lists for ro.product.cpu.abilist
+    auto abilist_prop_val = abilist64_prop_val;
+    if (abilist32_prop_val != EMPTY) {
+        if (abilist_prop_val != EMPTY) {
+            abilist_prop_val += ",";
+        }
+        abilist_prop_val += abilist32_prop_val;
+    }
+
+    // Set these properties
+    const std::pair<const char*, const std::string&> set_prop_list[] = {
+            {kAbilistProp, abilist_prop_val},
+            {kAbilist32Prop, abilist32_prop_val},
+            {kAbilist64Prop, abilist64_prop_val},
+    };
+    for (const auto& [prop, prop_val] : set_prop_list) {
+        LOG(INFO) << "Setting property '" << prop << "' to '" << prop_val << "'";
+
+        std::string error;
+        uint32_t res = PropertySet(prop, prop_val, &error);
+        if (res != PROP_SUCCESS) {
+            LOG(ERROR) << "Error setting property '" << prop << "': err=" << res << " (" << error
+                       << ")";
+        }
+    }
+}
+
 void PropertyLoadBootDefaults() {
     // We read the properties and their values into a map, in order to always allow properties
     // loaded in the later property files to override the properties in loaded in the earlier
@@ -957,8 +1020,6 @@
     load_properties_from_partition("odm", /* support_legacy_path_until */ 28);
     load_properties_from_partition("product", /* support_legacy_path_until */ 30);
 
-    load_properties_from_file("/factory/factory.prop", "ro.*", &properties);
-
     if (access(kDebugRamdiskProp, R_OK) == 0) {
         LOG(INFO) << "Loading " << kDebugRamdiskProp;
         load_properties_from_file(kDebugRamdiskProp, nullptr, &properties);
@@ -974,6 +1035,7 @@
 
     property_initialize_ro_product_props();
     property_derive_build_fingerprint();
+    property_initialize_ro_cpu_abilist();
 
     update_sys_usb_config();
 }
diff --git a/init/selinux.cpp b/init/selinux.cpp
index f03ca6b..0336936 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -45,7 +45,7 @@
 // 2) If these hashes do not match, then either /system or /system_ext or /product (or some of them)
 //    have been updated out of sync with /vendor (or /odm if it is present) and the init needs to
 //    compile the SEPolicy.  /system contains the SEPolicy compiler, secilc, and it is used by the
-//    LoadSplitPolicy() function below to compile the SEPolicy to a temp directory and load it.
+//    OpenSplitPolicy() function below to compile the SEPolicy to a temp directory and load it.
 //    That function contains even more documentation with the specific implementation details of how
 //    the SEPolicy is compiled if needed.
 
@@ -74,6 +74,7 @@
 #include "block_dev_initializer.h"
 #include "debug_ramdisk.h"
 #include "reboot_utils.h"
+#include "snapuserd_transition.h"
 #include "util.h"
 
 using namespace std::string_literals;
@@ -298,7 +299,12 @@
     return access(plat_policy_cil_file, R_OK) != -1;
 }
 
-bool LoadSplitPolicy() {
+struct PolicyFile {
+    unique_fd fd;
+    std::string path;
+};
+
+bool OpenSplitPolicy(PolicyFile* policy_file) {
     // IMPLEMENTATION NOTE: Split policy consists of three CIL files:
     // * platform -- policy needed due to logic contained in the system image,
     // * non-platform -- policy needed due to logic contained in the vendor image,
@@ -325,10 +331,8 @@
     if (!use_userdebug_policy && FindPrecompiledSplitPolicy(&precompiled_sepolicy_file)) {
         unique_fd fd(open(precompiled_sepolicy_file.c_str(), O_RDONLY | O_CLOEXEC | O_BINARY));
         if (fd != -1) {
-            if (selinux_android_load_policy_from_fd(fd, precompiled_sepolicy_file.c_str()) < 0) {
-                LOG(ERROR) << "Failed to load SELinux policy from " << precompiled_sepolicy_file;
-                return false;
-            }
+            policy_file->fd = std::move(fd);
+            policy_file->path = std::move(precompiled_sepolicy_file);
             return true;
         }
     }
@@ -446,34 +450,39 @@
     }
     unlink(compiled_sepolicy);
 
-    LOG(INFO) << "Loading compiled SELinux policy";
-    if (selinux_android_load_policy_from_fd(compiled_sepolicy_fd, compiled_sepolicy) < 0) {
-        LOG(ERROR) << "Failed to load SELinux policy from " << compiled_sepolicy;
-        return false;
-    }
-
+    policy_file->fd = std::move(compiled_sepolicy_fd);
+    policy_file->path = compiled_sepolicy;
     return true;
 }
 
-bool LoadMonolithicPolicy() {
-    LOG(VERBOSE) << "Loading SELinux policy from monolithic file";
-    if (selinux_android_load_policy() < 0) {
-        PLOG(ERROR) << "Failed to load monolithic SELinux policy";
+bool OpenMonolithicPolicy(PolicyFile* policy_file) {
+    static constexpr char kSepolicyFile[] = "/sepolicy";
+
+    LOG(VERBOSE) << "Opening SELinux policy from monolithic file";
+    policy_file->fd.reset(open(kSepolicyFile, O_RDONLY | O_CLOEXEC | O_NOFOLLOW));
+    if (policy_file->fd < 0) {
+        PLOG(ERROR) << "Failed to open monolithic SELinux policy";
         return false;
     }
+    policy_file->path = kSepolicyFile;
     return true;
 }
 
-bool LoadPolicy() {
-    return IsSplitPolicyDevice() ? LoadSplitPolicy() : LoadMonolithicPolicy();
-}
+void ReadPolicy(std::string* policy) {
+    PolicyFile policy_file;
 
-void SelinuxInitialize() {
-    LOG(INFO) << "Loading SELinux policy";
-    if (!LoadPolicy()) {
-        LOG(FATAL) << "Unable to load SELinux policy";
+    bool ok = IsSplitPolicyDevice() ? OpenSplitPolicy(&policy_file)
+                                    : OpenMonolithicPolicy(&policy_file);
+    if (!ok) {
+        LOG(FATAL) << "Unable to open SELinux policy";
     }
 
+    if (!android::base::ReadFdToString(policy_file.fd, policy)) {
+        PLOG(FATAL) << "Failed to read policy file: " << policy_file.path;
+    }
+}
+
+void SelinuxSetEnforcement() {
     bool kernel_enforcing = (security_getenforce() == 1);
     bool is_enforcing = IsEnforcing();
     if (kernel_enforcing != is_enforcing) {
@@ -670,6 +679,30 @@
     }
 }
 
+static void LoadSelinuxPolicy(std::string& policy) {
+    LOG(INFO) << "Loading SELinux policy";
+
+    set_selinuxmnt("/sys/fs/selinux");
+    if (security_load_policy(policy.data(), policy.size()) < 0) {
+        PLOG(FATAL) << "SELinux:  Could not load policy";
+    }
+}
+
+// The SELinux setup process is carefully orchestrated around snapuserd. Policy
+// must be loaded off dynamic partitions, and during an OTA, those partitions
+// cannot be read without snapuserd. But, with kernel-privileged snapuserd
+// running, loading the policy will immediately trigger audits.
+//
+// We use a five-step process to address this:
+//  (1) Read the policy into a string, with snapuserd running.
+//  (2) Rewrite the snapshot device-mapper tables, to generate new dm-user
+//      devices and to flush I/O.
+//  (3) Kill snapuserd, which no longer has any dm-user devices to attach to.
+//  (4) Load the sepolicy and issue critical restorecons in /dev, carefully
+//      avoiding anything that would read from /system.
+//  (5) Re-launch snapuserd and attach it to the dm-user devices from step (2).
+//
+// After this sequence, it is safe to enable enforcing mode and continue booting.
 int SetupSelinux(char** argv) {
     SetStdioToDevNull(argv);
     InitKernelLogging(argv);
@@ -682,9 +715,31 @@
 
     MountMissingSystemPartitions();
 
-    // Set up SELinux, loading the SELinux policy.
     SelinuxSetupKernelLogging();
-    SelinuxInitialize();
+
+    LOG(INFO) << "Opening SELinux policy";
+
+    // Read the policy before potentially killing snapuserd.
+    std::string policy;
+    ReadPolicy(&policy);
+
+    auto snapuserd_helper = SnapuserdSelinuxHelper::CreateIfNeeded();
+    if (snapuserd_helper) {
+        // Kill the old snapused to avoid audit messages. After this we cannot
+        // read from /system (or other dynamic partitions) until we call
+        // FinishTransition().
+        snapuserd_helper->StartTransition();
+    }
+
+    LoadSelinuxPolicy(policy);
+
+    if (snapuserd_helper) {
+        // Before enforcing, finish the pending snapuserd transition.
+        snapuserd_helper->FinishTransition();
+        snapuserd_helper = nullptr;
+    }
+
+    SelinuxSetEnforcement();
 
     // We're in the kernel domain and want to transition to the init domain.  File systems that
     // store SELabels in their xattrs, such as ext4 do not need an explicit restorecon here,
diff --git a/init/snapuserd_transition.cpp b/init/snapuserd_transition.cpp
new file mode 100644
index 0000000..19b5c57
--- /dev/null
+++ b/init/snapuserd_transition.cpp
@@ -0,0 +1,305 @@
+/*
+ * 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 "snapuserd_transition.h"
+
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/syscall.h>
+#include <sys/xattr.h>
+#include <unistd.h>
+
+#include <filesystem>
+#include <string>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+#include <libsnapshot/snapshot.h>
+#include <libsnapshot/snapuserd_client.h>
+#include <private/android_filesystem_config.h>
+#include <selinux/android.h>
+
+#include "block_dev_initializer.h"
+#include "service_utils.h"
+#include "util.h"
+
+namespace android {
+namespace init {
+
+using namespace std::string_literals;
+
+using android::base::unique_fd;
+using android::snapshot::SnapshotManager;
+using android::snapshot::SnapuserdClient;
+
+static constexpr char kSnapuserdPath[] = "/system/bin/snapuserd";
+static constexpr char kSnapuserdFirstStagePidVar[] = "FIRST_STAGE_SNAPUSERD_PID";
+static constexpr char kSnapuserdFirstStageFdVar[] = "FIRST_STAGE_SNAPUSERD_FD";
+static constexpr char kSnapuserdLabel[] = "u:object_r:snapuserd_exec:s0";
+static constexpr char kSnapuserdSocketLabel[] = "u:object_r:snapuserd_socket:s0";
+
+void LaunchFirstStageSnapuserd() {
+    SocketDescriptor socket_desc;
+    socket_desc.name = android::snapshot::kSnapuserdSocket;
+    socket_desc.type = SOCK_STREAM;
+    socket_desc.perm = 0660;
+    socket_desc.uid = AID_SYSTEM;
+    socket_desc.gid = AID_SYSTEM;
+
+    // We specify a label here even though it technically is not needed. During
+    // first_stage_mount there is no sepolicy loaded. Once sepolicy is loaded,
+    // we bypass the socket entirely.
+    auto socket = socket_desc.Create(kSnapuserdSocketLabel);
+    if (!socket.ok()) {
+        LOG(FATAL) << "Could not create snapuserd socket: " << socket.error();
+    }
+
+    pid_t pid = fork();
+    if (pid < 0) {
+        PLOG(FATAL) << "Cannot launch snapuserd; fork failed";
+    }
+    if (pid == 0) {
+        socket->Publish();
+        char arg0[] = "/system/bin/snapuserd";
+        char* const argv[] = {arg0, nullptr};
+        if (execv(arg0, argv) < 0) {
+            PLOG(FATAL) << "Cannot launch snapuserd; execv failed";
+        }
+        _exit(127);
+    }
+
+    setenv(kSnapuserdFirstStagePidVar, std::to_string(pid).c_str(), 1);
+
+    LOG(INFO) << "Relaunched snapuserd with pid: " << pid;
+}
+
+std::optional<pid_t> GetSnapuserdFirstStagePid() {
+    const char* pid_str = getenv(kSnapuserdFirstStagePidVar);
+    if (!pid_str) {
+        return {};
+    }
+
+    int pid = 0;
+    if (!android::base::ParseInt(pid_str, &pid)) {
+        LOG(FATAL) << "Could not parse pid in environment, " << kSnapuserdFirstStagePidVar << "="
+                   << pid_str;
+    }
+    return {pid};
+}
+
+static void RelabelLink(const std::string& link) {
+    selinux_android_restorecon(link.c_str(), 0);
+
+    std::string path;
+    if (android::base::Readlink(link, &path)) {
+        selinux_android_restorecon(path.c_str(), 0);
+    }
+}
+
+static void RelabelDeviceMapper() {
+    selinux_android_restorecon("/dev/device-mapper", 0);
+
+    std::error_code ec;
+    for (auto& iter : std::filesystem::directory_iterator("/dev/block", ec)) {
+        const auto& path = iter.path();
+        if (android::base::StartsWith(path.string(), "/dev/block/dm-")) {
+            selinux_android_restorecon(path.string().c_str(), 0);
+        }
+    }
+}
+
+static std::optional<int> GetRamdiskSnapuserdFd() {
+    const char* fd_str = getenv(kSnapuserdFirstStageFdVar);
+    if (!fd_str) {
+        return {};
+    }
+
+    int fd;
+    if (!android::base::ParseInt(fd_str, &fd)) {
+        LOG(FATAL) << "Could not parse fd in environment, " << kSnapuserdFirstStageFdVar << "="
+                   << fd_str;
+    }
+    return {fd};
+}
+
+void RestoreconRamdiskSnapuserd(int fd) {
+    if (fsetxattr(fd, XATTR_NAME_SELINUX, kSnapuserdLabel, strlen(kSnapuserdLabel) + 1, 0) < 0) {
+        PLOG(FATAL) << "fsetxattr snapuserd failed";
+    }
+}
+
+SnapuserdSelinuxHelper::SnapuserdSelinuxHelper(std::unique_ptr<SnapshotManager>&& sm, pid_t old_pid)
+    : sm_(std::move(sm)), old_pid_(old_pid) {
+    // Only dm-user device names change during transitions, so the other
+    // devices are expected to be present.
+    sm_->SetUeventRegenCallback([this](const std::string& device) -> bool {
+        if (android::base::StartsWith(device, "/dev/dm-user/")) {
+            return block_dev_init_.InitDmUser(android::base::Basename(device));
+        }
+        return true;
+    });
+}
+
+void SnapuserdSelinuxHelper::StartTransition() {
+    LOG(INFO) << "Starting SELinux transition of snapuserd";
+
+    // The restorecon path reads from /system etc, so make sure any reads have
+    // been cached before proceeding.
+    auto handle = selinux_android_file_context_handle();
+    if (!handle) {
+        LOG(FATAL) << "Could not create SELinux file context handle";
+    }
+    selinux_android_set_sehandle(handle);
+
+    // We cannot access /system after the transition, so make sure init is
+    // pinned in memory.
+    if (mlockall(MCL_CURRENT) < 0) {
+        LOG(FATAL) << "mlockall failed";
+    }
+
+    argv_.emplace_back("snapuserd");
+    argv_.emplace_back("-no_socket");
+    if (!sm_->DetachSnapuserdForSelinux(&argv_)) {
+        LOG(FATAL) << "Could not perform selinux transition";
+    }
+
+    // Make sure the process is gone so we don't have any selinux audits.
+    KillFirstStageSnapuserd(old_pid_);
+}
+
+void SnapuserdSelinuxHelper::FinishTransition() {
+    RelabelLink("/dev/block/by-name/super");
+    RelabelDeviceMapper();
+
+    selinux_android_restorecon("/dev/null", 0);
+    selinux_android_restorecon("/dev/urandom", 0);
+    selinux_android_restorecon("/dev/kmsg", 0);
+    selinux_android_restorecon("/dev/dm-user", SELINUX_ANDROID_RESTORECON_RECURSE);
+
+    RelaunchFirstStageSnapuserd();
+
+    if (munlockall() < 0) {
+        PLOG(ERROR) << "munlockall failed";
+    }
+}
+
+void SnapuserdSelinuxHelper::RelaunchFirstStageSnapuserd() {
+    auto fd = GetRamdiskSnapuserdFd();
+    if (!fd) {
+        LOG(FATAL) << "Environment variable " << kSnapuserdFirstStageFdVar << " was not set!";
+    }
+    unsetenv(kSnapuserdFirstStageFdVar);
+
+    RestoreconRamdiskSnapuserd(fd.value());
+
+    pid_t pid = fork();
+    if (pid < 0) {
+        PLOG(FATAL) << "Fork to relaunch snapuserd failed";
+    }
+    if (pid > 0) {
+        // We don't need the descriptor anymore, and it should be closed to
+        // avoid leaking into subprocesses.
+        close(fd.value());
+
+        setenv(kSnapuserdFirstStagePidVar, std::to_string(pid).c_str(), 1);
+
+        LOG(INFO) << "Relaunched snapuserd with pid: " << pid;
+        return;
+    }
+
+    // Make sure the descriptor is gone after we exec.
+    if (fcntl(fd.value(), F_SETFD, FD_CLOEXEC) < 0) {
+        PLOG(FATAL) << "fcntl FD_CLOEXEC failed for snapuserd fd";
+    }
+
+    std::vector<char*> argv;
+    for (auto& arg : argv_) {
+        argv.emplace_back(arg.data());
+    }
+    argv.emplace_back(nullptr);
+
+    int rv = syscall(SYS_execveat, fd.value(), "", reinterpret_cast<char* const*>(argv.data()),
+                     nullptr, AT_EMPTY_PATH);
+    if (rv < 0) {
+        PLOG(FATAL) << "Failed to execveat() snapuserd";
+    }
+}
+
+std::unique_ptr<SnapuserdSelinuxHelper> SnapuserdSelinuxHelper::CreateIfNeeded() {
+    if (IsRecoveryMode()) {
+        return nullptr;
+    }
+
+    auto old_pid = GetSnapuserdFirstStagePid();
+    if (!old_pid) {
+        return nullptr;
+    }
+
+    auto sm = SnapshotManager::NewForFirstStageMount();
+    if (!sm) {
+        LOG(FATAL) << "Unable to create SnapshotManager";
+    }
+    return std::make_unique<SnapuserdSelinuxHelper>(std::move(sm), old_pid.value());
+}
+
+void KillFirstStageSnapuserd(pid_t pid) {
+    if (kill(pid, SIGTERM) < 0 && errno != ESRCH) {
+        LOG(ERROR) << "Kill snapuserd pid failed: " << pid;
+    } else {
+        LOG(INFO) << "Sent SIGTERM to snapuserd process " << pid;
+    }
+}
+
+void CleanupSnapuserdSocket() {
+    auto socket_path = ANDROID_SOCKET_DIR "/"s + android::snapshot::kSnapuserdSocket;
+    if (access(socket_path.c_str(), F_OK) != 0) {
+        return;
+    }
+
+    // Tell the daemon to stop accepting connections and to gracefully exit
+    // once all outstanding handlers have terminated.
+    if (auto client = SnapuserdClient::Connect(android::snapshot::kSnapuserdSocket, 3s)) {
+        client->DetachSnapuserd();
+    }
+
+    // Unlink the socket so we can create it again in second-stage.
+    if (unlink(socket_path.c_str()) < 0) {
+        PLOG(FATAL) << "unlink " << socket_path << " failed";
+    }
+}
+
+void SaveRamdiskPathToSnapuserd() {
+    int fd = open(kSnapuserdPath, O_PATH);
+    if (fd < 0) {
+        PLOG(FATAL) << "Unable to open snapuserd: " << kSnapuserdPath;
+    }
+
+    auto value = std::to_string(fd);
+    if (setenv(kSnapuserdFirstStageFdVar, value.c_str(), 1) < 0) {
+        PLOG(FATAL) << "setenv failed: " << kSnapuserdFirstStageFdVar << "=" << value;
+    }
+}
+
+bool IsFirstStageSnapuserdRunning() {
+    return GetSnapuserdFirstStagePid().has_value();
+}
+
+}  // namespace init
+}  // namespace android
diff --git a/init/snapuserd_transition.h b/init/snapuserd_transition.h
new file mode 100644
index 0000000..a5ab652
--- /dev/null
+++ b/init/snapuserd_transition.h
@@ -0,0 +1,87 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <sys/types.h>
+
+#include <optional>
+#include <string>
+#include <vector>
+
+#include <libsnapshot/snapshot.h>
+
+#include "block_dev_initializer.h"
+
+namespace android {
+namespace init {
+
+// Fork and exec a new copy of snapuserd.
+void LaunchFirstStageSnapuserd();
+
+class SnapuserdSelinuxHelper final {
+    using SnapshotManager = android::snapshot::SnapshotManager;
+
+  public:
+    SnapuserdSelinuxHelper(std::unique_ptr<SnapshotManager>&& sm, pid_t old_pid);
+
+    void StartTransition();
+    void FinishTransition();
+
+    // Return a helper for facilitating the selinux transition of snapuserd.
+    // If snapuserd is not in use, null is returned. StartTransition() should
+    // be called after reading policy. FinishTransition() should be called
+    // after loading policy. In between, no reads of /system or other dynamic
+    // partitions are possible.
+    static std::unique_ptr<SnapuserdSelinuxHelper> CreateIfNeeded();
+
+  private:
+    void RelaunchFirstStageSnapuserd();
+    void ExecSnapuserd();
+
+    std::unique_ptr<SnapshotManager> sm_;
+    BlockDevInitializer block_dev_init_;
+    pid_t old_pid_;
+    std::vector<std::string> argv_;
+};
+
+// Remove /dev/socket/snapuserd. This ensures that (1) the existing snapuserd
+// will receive no new requests, and (2) the next copy we transition to can
+// own the socket.
+void CleanupSnapuserdSocket();
+
+// Kill an instance of snapuserd given a pid.
+void KillFirstStageSnapuserd(pid_t pid);
+
+// Save an open fd to /system/bin (in the ramdisk) into an environment. This is
+// used to later execveat() snapuserd.
+void SaveRamdiskPathToSnapuserd();
+
+// Returns true if first-stage snapuserd is running.
+bool IsFirstStageSnapuserdRunning();
+
+// Return the pid of the first-stage instances of snapuserd, if it was started.
+std::optional<pid_t> GetSnapuserdFirstStagePid();
+
+// Save an open fd to /system/bin (in the ramdisk) into an environment. This is
+// used to later execveat() snapuserd.
+void SaveRamdiskPathToSnapuserd();
+
+// Returns true if first-stage snapuserd is running.
+bool IsFirstStageSnapuserdRunning();
+
+}  // namespace init
+}  // namespace android
diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index cf809f1..d46aeab 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -210,9 +210,6 @@
                 "uevent.cpp",
             ],
         },
-        bionic: {
-            header_libs: ["bionic_libc_platform_headers"],
-        },
 
         android_arm: {
             sanitize: {
diff --git a/libcutils/memory.cpp b/libcutils/memory.cpp
index f526520..5a410c2 100644
--- a/libcutils/memory.cpp
+++ b/libcutils/memory.cpp
@@ -18,19 +18,18 @@
 
 #include <log/log.h>
 
-#ifdef __BIONIC__
-#include <bionic/malloc.h>
+#if !defined(__APPLE__)
+#include <malloc.h>
 #endif
 
 void process_disable_memory_mitigations() {
     bool success = false;
 #ifdef __BIONIC__
-    // TODO(b/158870657) is fixed and scudo is used globally, we can assert when an
-    // an error is returned.
-
-    success = android_mallopt(M_DISABLE_MEMORY_MITIGATIONS, nullptr, 0);
+    success = mallopt(M_BIONIC_DISABLE_MEMORY_MITIGATIONS, 0);
 #endif
 
+    // TODO: if b/158870657 is fixed and scudo is used globally,
+    // we can assert on failure rather than just log.
     if (success) {
         ALOGI("Disabled memory mitigations for process.");
     } else {
diff --git a/libprocessgroup/cgroup_map.cpp b/libprocessgroup/cgroup_map.cpp
index b82b0ab..5ca0967 100644
--- a/libprocessgroup/cgroup_map.cpp
+++ b/libprocessgroup/cgroup_map.cpp
@@ -71,7 +71,7 @@
     if (!HasValue()) return false;
 
     if (state_ == UNKNOWN) {
-        if (ACgroupController_getFlags != nullptr) {
+        if (__builtin_available(android 30, *)) {
             uint32_t flags = ACgroupController_getFlags(controller_);
             state_ = (flags & CGROUPRC_CONTROLLER_FLAG_MOUNTED) != 0 ? USABLE : MISSING;
         } else {
@@ -172,7 +172,7 @@
     auto controller_count = ACgroupFile_getControllerCount();
     for (uint32_t i = 0; i < controller_count; ++i) {
         const ACgroupController* controller = ACgroupFile_getController(i);
-        if (ACgroupController_getFlags != nullptr) {
+        if (__builtin_available(android 30, *)) {
             LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver "
                       << ACgroupController_getVersion(controller) << " path "
                       << ACgroupController_getPath(controller) << " flags "
diff --git a/libprocessgroup/cgrouprc/include/android/cgrouprc.h b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
index 7e74432..9a79954 100644
--- a/libprocessgroup/cgrouprc/include/android/cgrouprc.h
+++ b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
@@ -28,8 +28,6 @@
 struct ACgroupController;
 typedef struct ACgroupController ACgroupController;
 
-#if __ANDROID_API__ >= __ANDROID_API_Q__
-
 // ACgroupFile
 
 /**
@@ -71,8 +69,6 @@
 #define CGROUPRC_CONTROLLER_FLAG_MOUNTED 0x1
 #define CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION 0x2
 
-#if __ANDROID_API__ >= __ANDROID_API_R__
-
 /**
  * Returns the flags bitmask of the given controller.
  * If the given controller is null, return 0.
@@ -80,8 +76,6 @@
 __attribute__((warn_unused_result, weak)) uint32_t ACgroupController_getFlags(
         const ACgroupController*) __INTRODUCED_IN(30);
 
-#endif
-
 /**
  * Returns the name of the given controller.
  * If the given controller is null, return nullptr.
@@ -97,5 +91,3 @@
         __INTRODUCED_IN(29);
 
 __END_DECLS
-
-#endif
diff --git a/libsync/include/ndk/sync.h b/libsync/include/ndk/sync.h
index 2a59e35..38ccb68 100644
--- a/libsync/include/ndk/sync.h
+++ b/libsync/include/ndk/sync.h
@@ -33,8 +33,6 @@
 
 __BEGIN_DECLS
 
-#if __ANDROID_API__ >= 26
-
 /* Fences indicate the status of an asynchronous task. They are initially
  * in unsignaled state (0), and make a one-time transition to either signaled
  * (1) or error (< 0) state. A sync file is a collection of one or more fences;
@@ -101,8 +99,6 @@
  */
 void sync_file_info_free(struct sync_file_info* info) __INTRODUCED_IN(26);
 
-#endif /* __ANDROID_API__ >= 26 */
-
 __END_DECLS
 
 #endif /* ANDROID_SYNC_H */
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 4478bea..19c00f9 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -856,13 +856,6 @@
     wait_for_prop apexd.status activated
     perform_apex_config
 
-    # Lock the fs-verity keyring, so no more keys can be added
-    exec -- /system/bin/fsverity_init --lock
-
-    # After apexes are mounted, tell keymaster early boot has ended, so it will
-    # stop allowing use of early-boot keys
-    exec - system system -- /system/bin/vdc keymaster earlyBootEnded
-
     # Special-case /data/media/obb per b/64566063
     mkdir /data/media 0770 media_rw media_rw encryption=None
     exec - media_rw media_rw -- /system/bin/chattr +F /data/media
@@ -872,15 +865,22 @@
 
     init_user0
 
+    # Set SELinux security contexts on upgrade or policy update.
+    restorecon --recursive --skip-ce /data
+
+    # After apexes are mounted, tell keymaster early boot has ended, so it will
+    # stop allowing use of early-boot keys
+    exec - system system -- /system/bin/vdc keymaster earlyBootEnded
+
+    # Lock the fs-verity keyring, so no more keys can be added
+    exec -- /system/bin/fsverity_init --lock
+
     # Allow apexd to snapshot and restore device encrypted apex data in the case
     # of a rollback. This should be done immediately after DE_user data keys
     # are loaded. APEXes should not access this data until this has been
     # completed and apexd.status becomes "ready".
     exec_start apexd-snapshotde
 
-    # Set SELinux security contexts on upgrade or policy update.
-    restorecon --recursive --skip-ce /data
-
     # Check any timezone data in /data is newer than the copy in the time zone data
     # module, delete if not.
     exec - system system -- /system/bin/tzdatacheck /apex/com.android.tzdata/etc/tz /data/misc/zoneinfo
@@ -934,6 +934,9 @@
     write /proc/sys/vm/dirty_expire_centisecs 200
     write /proc/sys/vm/dirty_background_ratio  5
 
+on property:sys.boot_completed=1 && property:init.mount_debugfs=1
+   umount /sys/kernel/debug
+
 on boot
     # basic network init
     ifup lo
@@ -1202,6 +1205,10 @@
 on property:sys.boot_completed=1 && property:sys.init.userspace_reboot.in_progress=1
   setprop sys.init.userspace_reboot.in_progress ""
 
+on early-init && property:init.mount_debugfs=1
+    mount debugfs debugfs /sys/kernel/debug
+    chmod 0755 /sys/kernel/debug
+
 # Migrate tasks again in case kernel threads are created during boot
 on property:sys.boot_completed=1
   copy_per_line /dev/cpuctl/tasks /dev/cpuctl/system/tasks
diff --git a/rootdir/ueventd.rc b/rootdir/ueventd.rc
index a1e9b12..64a64d2 100644
--- a/rootdir/ueventd.rc
+++ b/rootdir/ueventd.rc
@@ -48,6 +48,7 @@
 /dev/pmsg0                0222   root       log
 /dev/dma_heap/system      0444   system     system
 /dev/dma_heap/system-uncached      0444   system     system
+/dev/dma_heap/system-secure        0444   system     system
 
 # kms driver for drm based gpu
 /dev/dri/*                0666   root       graphics
diff --git a/trusty/confirmationui/fuzz/Android.bp b/trusty/confirmationui/fuzz/Android.bp
index 0819c21..635966f 100644
--- a/trusty/confirmationui/fuzz/Android.bp
+++ b/trusty/confirmationui/fuzz/Android.bp
@@ -16,4 +16,8 @@
     name: "trusty_confirmationui_fuzzer",
     defaults: ["trusty_fuzzer_defaults"],
     srcs: ["fuzz.cpp"],
+
+    // The initial corpus for this fuzzer was derived by dumping bytes from
+    // ConfirmationUI VTS.
+    corpus: ["corpus/*"],
 }
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-2ekYc2 b/trusty/confirmationui/fuzz/corpus/confirmationui-2ekYc2
new file mode 100644
index 0000000..53fe0c9
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-2ekYc2
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-5yTG3f b/trusty/confirmationui/fuzz/corpus/confirmationui-5yTG3f
new file mode 100644
index 0000000..d627b01
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-5yTG3f
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-6l8Soq b/trusty/confirmationui/fuzz/corpus/confirmationui-6l8Soq
new file mode 100644
index 0000000..bda80fd
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-6l8Soq
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-7kFpGO b/trusty/confirmationui/fuzz/corpus/confirmationui-7kFpGO
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-7kFpGO
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-92m2f3 b/trusty/confirmationui/fuzz/corpus/confirmationui-92m2f3
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-92m2f3
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-ALYIzO b/trusty/confirmationui/fuzz/corpus/confirmationui-ALYIzO
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-ALYIzO
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-AcIMhR b/trusty/confirmationui/fuzz/corpus/confirmationui-AcIMhR
new file mode 100644
index 0000000..f5854f8
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-AcIMhR
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-AieaIi b/trusty/confirmationui/fuzz/corpus/confirmationui-AieaIi
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-AieaIi
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-BdqX5j b/trusty/confirmationui/fuzz/corpus/confirmationui-BdqX5j
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-BdqX5j
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-JBPIGs b/trusty/confirmationui/fuzz/corpus/confirmationui-JBPIGs
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-JBPIGs
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-MWHw4T b/trusty/confirmationui/fuzz/corpus/confirmationui-MWHw4T
new file mode 100644
index 0000000..0dc6e91
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-MWHw4T
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-TZzVLO b/trusty/confirmationui/fuzz/corpus/confirmationui-TZzVLO
new file mode 100644
index 0000000..927d64d
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-TZzVLO
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-WwdA3B b/trusty/confirmationui/fuzz/corpus/confirmationui-WwdA3B
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-WwdA3B
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-globJV b/trusty/confirmationui/fuzz/corpus/confirmationui-globJV
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-globJV
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-hzUgjD b/trusty/confirmationui/fuzz/corpus/confirmationui-hzUgjD
new file mode 100644
index 0000000..87870ca
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-hzUgjD
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-jXC78o b/trusty/confirmationui/fuzz/corpus/confirmationui-jXC78o
new file mode 100644
index 0000000..0b274bf
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-jXC78o
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-kykxni b/trusty/confirmationui/fuzz/corpus/confirmationui-kykxni
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-kykxni
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-npHe8t b/trusty/confirmationui/fuzz/corpus/confirmationui-npHe8t
new file mode 100644
index 0000000..87870ca
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-npHe8t
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-rPgnyI b/trusty/confirmationui/fuzz/corpus/confirmationui-rPgnyI
new file mode 100644
index 0000000..87870ca
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-rPgnyI
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-uCJ1Me b/trusty/confirmationui/fuzz/corpus/confirmationui-uCJ1Me
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-uCJ1Me
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-wAQEjK b/trusty/confirmationui/fuzz/corpus/confirmationui-wAQEjK
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-wAQEjK
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-xjtOks b/trusty/confirmationui/fuzz/corpus/confirmationui-xjtOks
new file mode 100644
index 0000000..b4a1c49
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-xjtOks
Binary files differ
diff --git a/trusty/confirmationui/fuzz/corpus/confirmationui-zKFIjN b/trusty/confirmationui/fuzz/corpus/confirmationui-zKFIjN
new file mode 100644
index 0000000..5adf905
--- /dev/null
+++ b/trusty/confirmationui/fuzz/corpus/confirmationui-zKFIjN
Binary files differ
diff --git a/trusty/confirmationui/fuzz/fuzz.cpp b/trusty/confirmationui/fuzz/fuzz.cpp
index aa132e8..df2517c 100644
--- a/trusty/confirmationui/fuzz/fuzz.cpp
+++ b/trusty/confirmationui/fuzz/fuzz.cpp
@@ -14,10 +14,7 @@
  * limitations under the License.
  */
 
-#undef NDEBUG
-
-#include <assert.h>
-#include <log/log.h>
+#include <iostream>
 #include <stdlib.h>
 #include <trusty/coverage/coverage.h>
 #include <trusty/fuzz/counters.h>
@@ -30,6 +27,7 @@
 
 #define TIPC_DEV "/dev/trusty-ipc-dev0"
 #define CONFIRMATIONUI_PORT "com.android.trusty.confirmationui"
+#define CONFIRMATIONUI_MODULE_NAME "confirmationui.syms.elf"
 
 /* ConfirmationUI TA's UUID is 7dee2364-c036-425b-b086-df0f6c233c1b */
 static struct uuid confirmationui_uuid = {
@@ -39,16 +37,30 @@
     {0xb0, 0x86, 0xdf, 0x0f, 0x6c, 0x23, 0x3c, 0x1b},
 };
 
-static CoverageRecord record(TIPC_DEV, &confirmationui_uuid);
+/* The format of the packets is as following:
+ * 16 bits (uint16_t, header) + payload bytes
+ * The 16 bits header spicify the number of bytes of payload (header excluded).
+ */
+struct data_packet {
+    uint16_t header;
+    uint8_t payload[];
+};
+
+static CoverageRecord record(TIPC_DEV, &confirmationui_uuid, CONFIRMATIONUI_MODULE_NAME);
 
 extern "C" int LLVMFuzzerInitialize(int* /* argc */, char*** /* argv */) {
     auto ret = record.Open();
-    assert(ret.ok());
+    if (!ret.ok()) {
+        std::cerr << ret.error() << std::endl;
+        exit(-1);
+    }
     return 0;
 }
 
+/* Each corpus contains one or more data packets. */
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     static uint8_t buf[TIPC_MAX_MSG_SIZE];
+    size_t data_idx = 0;
 
     ExtraCounters counters(&record);
     counters.Reset();
@@ -59,16 +71,22 @@
         android::trusty::fuzz::Abort();
     }
 
-    /* Write message to confirmationui server */
-    ret = ta.Write(data, size);
-    if (!ret.ok()) {
-        return -1;
-    }
+    while (data_idx < size) {
+        struct data_packet* data_packet_ptr = (struct data_packet*)&data[data_idx];
+        size_t payload_size = data_packet_ptr->header;
+        data_idx += data_packet_ptr->header + sizeof(data_packet_ptr->header);
 
-    /* Read message from confirmationui server */
-    ret = ta.Read(&buf, sizeof(buf));
-    if (!ret.ok()) {
-        return -1;
+        /* Write message to confirmationui server */
+        ret = ta.Write(data_packet_ptr->payload, payload_size);
+        if (!ret.ok()) {
+            return -1;
+        }
+
+        /* Read message from confirmationui server */
+        ret = ta.Read(&buf, sizeof(buf));
+        if (!ret.ok()) {
+            return -1;
+        }
     }
 
     return 0;
diff --git a/trusty/coverage/Android.bp b/trusty/coverage/Android.bp
index 6038d44..daa6f03 100644
--- a/trusty/coverage/Android.bp
+++ b/trusty/coverage/Android.bp
@@ -28,6 +28,7 @@
     shared_libs: [
         "libbase",
         "liblog",
+        "libdmabufheap",
     ],
 }
 
@@ -43,6 +44,7 @@
     shared_libs: [
         "libbase",
         "liblog",
+        "libdmabufheap",
     ],
     require_root: true,
 }
diff --git a/trusty/coverage/coverage.cpp b/trusty/coverage/coverage.cpp
index f383dd1..5eccdc5 100644
--- a/trusty/coverage/coverage.cpp
+++ b/trusty/coverage/coverage.cpp
@@ -16,10 +16,12 @@
 
 #define LOG_TAG "coverage"
 
+#include <BufferAllocator/BufferAllocator.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/unique_fd.h>
 #include <assert.h>
+#include <log/log.h>
 #include <stdio.h>
 #include <sys/mman.h>
 #include <sys/uio.h>
@@ -37,6 +39,8 @@
 using android::base::ErrnoError;
 using android::base::Error;
 using std::string;
+using std::to_string;
+using std::unique_ptr;
 
 static inline uintptr_t RoundPageUp(uintptr_t val) {
     return (val + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
@@ -46,12 +50,29 @@
     : tipc_dev_(std::move(tipc_dev)),
       coverage_srv_fd_(-1),
       uuid_(*uuid),
+      sancov_filename_(),
+      record_len_(0),
+      shm_(NULL),
+      shm_len_(0) {}
+
+CoverageRecord::CoverageRecord(string tipc_dev, struct uuid* uuid, string module_name)
+    : tipc_dev_(std::move(tipc_dev)),
+      coverage_srv_fd_(-1),
+      uuid_(*uuid),
+      sancov_filename_(module_name + "." + to_string(getpid()) + ".sancov"),
       record_len_(0),
       shm_(NULL),
       shm_len_(0) {}
 
 CoverageRecord::~CoverageRecord() {
     if (shm_) {
+        if (sancov_filename_) {
+            auto res = SaveSancovFile(*sancov_filename_);
+            if (!res.ok()) {
+                ALOGE("Could not write sancov file for module: %s\n", sancov_filename_->c_str());
+            }
+        }
+
         munmap((void*)shm_, shm_len_);
     }
 }
@@ -114,24 +135,23 @@
     record_len_ = resp.open_args.record_len;
     shm_len_ = RoundPageUp(record_len_);
 
-    fd = memfd_create("trusty-coverage", 0);
+    BufferAllocator allocator;
+
+    fd = allocator.Alloc("system", shm_len_);
     if (fd < 0) {
-        return ErrnoError() << "failed to create memfd: ";
+        return ErrnoError() << "failed to create dmabuf of size " << shm_len_
+                            << " err code: " << fd;
     }
-    unique_fd memfd(fd);
+    unique_fd dma_buf(fd);
 
-    if (ftruncate(memfd, shm_len_) < 0) {
-        return ErrnoError() << "failed to resize memfd: ";
-    }
-
-    void* shm = mmap(0, shm_len_, PROT_READ | PROT_WRITE, MAP_SHARED, memfd, 0);
+    void* shm = mmap(0, shm_len_, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf, 0);
     if (shm == MAP_FAILED) {
         return ErrnoError() << "failed to map memfd: ";
     }
 
     req.hdr.cmd = COVERAGE_CLIENT_CMD_SHARE_RECORD;
     req.share_record_args.shm_len = shm_len_;
-    ret = Rpc(&req, memfd, &resp);
+    ret = Rpc(&req, dma_buf, &resp);
     if (!ret.ok()) {
         return Error() << "failed to send shared memory: ";
     }
diff --git a/trusty/coverage/include/trusty/coverage/coverage.h b/trusty/coverage/include/trusty/coverage/coverage.h
index b6d46eb..5da68da 100644
--- a/trusty/coverage/include/trusty/coverage/coverage.h
+++ b/trusty/coverage/include/trusty/coverage/coverage.h
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include <optional>
 #include <string>
 
 #include <android-base/result.h>
@@ -32,7 +33,18 @@
 
 class CoverageRecord {
   public:
+    /**
+     * Create a coverage record interface. Coverage will not be written to a
+     * sancov output file on completion.
+     */
     CoverageRecord(std::string tipc_dev, struct uuid* uuid);
+
+    /**
+     * Create a coverage record interface. On destruction, write this coverage
+     * to the given sancov filename.
+     */
+    CoverageRecord(std::string tipc_dev, struct uuid* uuid, std::string module_name);
+
     ~CoverageRecord();
     Result<void> Open();
     void ResetFullRecord();
@@ -58,6 +70,7 @@
     std::string tipc_dev_;
     unique_fd coverage_srv_fd_;
     struct uuid uuid_;
+    std::optional<std::string> sancov_filename_;
     size_t record_len_;
     volatile void* shm_;
     size_t shm_len_;
diff --git a/trusty/fuzz/counters.cpp b/trusty/fuzz/counters.cpp
index 8c79475..1e863ac 100644
--- a/trusty/fuzz/counters.cpp
+++ b/trusty/fuzz/counters.cpp
@@ -21,6 +21,7 @@
 #include <trusty/fuzz/counters.h>
 
 #include <android-base/logging.h>
+#include <log/log.h>
 #include <trusty/coverage/coverage.h>
 #include <trusty/coverage/tipc.h>
 
@@ -32,7 +33,8 @@
  * We don't know how many counters the coverage record will contain. So, eyeball
  * the size of this section.
  */
-__attribute__((section("__libfuzzer_extra_counters"))) volatile uint8_t counters[PAGE_SIZE];
+static const size_t kMaxNumCounters = 0x4000;
+__attribute__((section("__libfuzzer_extra_counters"))) volatile uint8_t counters[kMaxNumCounters];
 
 namespace android {
 namespace trusty {
@@ -62,8 +64,16 @@
     volatile uint8_t* end = NULL;
 
     record_->GetRawCounts(&begin, &end);
+    if (!begin || !end) {
+        ALOGE("Could not get raw counts from coverage record\n");
+        return;
+    }
 
     size_t num_counters = end - begin;
+    if (num_counters > kMaxNumCounters) {
+        ALOGE("Too many counters (%zu) to fit in the extra counters section!\n", num_counters);
+        num_counters = kMaxNumCounters;
+    }
     for (size_t i = 0; i < num_counters; i++) {
         *(counters + i) = *(begin + i);
     }
diff --git a/trusty/fuzz/test/fuzz.cpp b/trusty/fuzz/test/fuzz.cpp
index 28bb3f7..e7913db 100644
--- a/trusty/fuzz/test/fuzz.cpp
+++ b/trusty/fuzz/test/fuzz.cpp
@@ -14,15 +14,12 @@
  * limitations under the License.
  */
 
-#undef NDEBUG
-
-#include <assert.h>
-#include <log/log.h>
 #include <stdlib.h>
 #include <trusty/coverage/coverage.h>
 #include <trusty/fuzz/counters.h>
 #include <trusty/fuzz/utils.h>
 #include <unistd.h>
+#include <iostream>
 
 using android::trusty::coverage::CoverageRecord;
 using android::trusty::fuzz::ExtraCounters;
@@ -43,7 +40,10 @@
 
 extern "C" int LLVMFuzzerInitialize(int* /* argc */, char*** /* argv */) {
     auto ret = record.Open();
-    assert(ret.ok());
+    if (!ret.ok()) {
+        std::cerr << ret.error() << std::endl;
+        exit(-1);
+    }
     return 0;
 }
 
diff --git a/trusty/gatekeeper/fuzz/fuzz.cpp b/trusty/gatekeeper/fuzz/fuzz.cpp
index c0e8abb..7bfd7d1 100644
--- a/trusty/gatekeeper/fuzz/fuzz.cpp
+++ b/trusty/gatekeeper/fuzz/fuzz.cpp
@@ -14,15 +14,12 @@
  * limitations under the License.
  */
 
-#undef NDEBUG
-
-#include <assert.h>
-#include <log/log.h>
 #include <stdlib.h>
 #include <trusty/coverage/coverage.h>
 #include <trusty/fuzz/counters.h>
 #include <trusty/fuzz/utils.h>
 #include <unistd.h>
+#include <iostream>
 
 using android::trusty::coverage::CoverageRecord;
 using android::trusty::fuzz::ExtraCounters;
@@ -30,6 +27,7 @@
 
 #define TIPC_DEV "/dev/trusty-ipc-dev0"
 #define GATEKEEPER_PORT "com.android.trusty.gatekeeper"
+#define GATEKEEPER_MODULE_NAME "gatekeeper.syms.elf"
 
 /* Gatekeeper TA's UUID is 38ba0cdc-df0e-11e4-9869-233fb6ae4795 */
 static struct uuid gatekeeper_uuid = {
@@ -39,11 +37,14 @@
         {0x98, 0x69, 0x23, 0x3f, 0xb6, 0xae, 0x47, 0x95},
 };
 
-static CoverageRecord record(TIPC_DEV, &gatekeeper_uuid);
+static CoverageRecord record(TIPC_DEV, &gatekeeper_uuid, GATEKEEPER_MODULE_NAME);
 
 extern "C" int LLVMFuzzerInitialize(int* /* argc */, char*** /* argv */) {
     auto ret = record.Open();
-    assert(ret.ok());
+    if (!ret.ok()) {
+        std::cerr << ret.error() << std::endl;
+        exit(-1);
+    }
     return 0;
 }
 
diff --git a/trusty/keymaster/fuzz/Android.bp b/trusty/keymaster/fuzz/Android.bp
new file mode 100644
index 0000000..da9f9ec
--- /dev/null
+++ b/trusty/keymaster/fuzz/Android.bp
@@ -0,0 +1,19 @@
+// 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.
+
+cc_fuzz {
+    name: "trusty_keymaster_fuzzer",
+    defaults: ["trusty_fuzzer_defaults"],
+    srcs: ["fuzz.cpp"],
+}
diff --git a/trusty/keymaster/fuzz/fuzz.cpp b/trusty/keymaster/fuzz/fuzz.cpp
new file mode 100644
index 0000000..4ac97bb
--- /dev/null
+++ b/trusty/keymaster/fuzz/fuzz.cpp
@@ -0,0 +1,76 @@
+/*
+ * 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 <stdlib.h>
+#include <trusty/coverage/coverage.h>
+#include <trusty/fuzz/counters.h>
+#include <trusty/fuzz/utils.h>
+#include <unistd.h>
+#include <iostream>
+
+using android::trusty::coverage::CoverageRecord;
+using android::trusty::fuzz::ExtraCounters;
+using android::trusty::fuzz::TrustyApp;
+
+#define TIPC_DEV "/dev/trusty-ipc-dev0"
+#define KEYMASTER_PORT "com.android.trusty.keymaster"
+#define KEYMASTER_MODULE_FILENAME "keymaster.syms.elf"
+
+/* Keymaster TA's UUID is 5f902ace-5e5c-4cd8-ae54-87b88c22ddaf */
+static struct uuid keymaster_uuid = {
+        0x5f902ace,
+        0x5e5c,
+        0x4cd8,
+        {0xae, 0x54, 0x87, 0xb8, 0x8c, 0x22, 0xdd, 0xaf},
+};
+
+static CoverageRecord record(TIPC_DEV, &keymaster_uuid, KEYMASTER_MODULE_FILENAME);
+
+extern "C" int LLVMFuzzerInitialize(int* /* argc */, char*** /* argv */) {
+    auto ret = record.Open();
+    if (!ret.ok()) {
+        std::cerr << ret.error() << std::endl;
+        exit(-1);
+    }
+    return 0;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    static uint8_t buf[TIPC_MAX_MSG_SIZE];
+
+    ExtraCounters counters(&record);
+    counters.Reset();
+
+    android::trusty::fuzz::TrustyApp ta(TIPC_DEV, KEYMASTER_PORT);
+    auto ret = ta.Connect();
+    if (!ret.ok()) {
+        android::trusty::fuzz::Abort();
+    }
+
+    /* Send message to test server */
+    ret = ta.Write(data, size);
+    if (!ret.ok()) {
+        return -1;
+    }
+
+    /* Read message from test server */
+    ret = ta.Read(&buf, sizeof(buf));
+    if (!ret.ok()) {
+        return -1;
+    }
+
+    return 0;
+}