libsnapshot: Only enable compression when the corresponding bit is set in DeltaArchiveManifest.

Test: vts_libsnapshot_test
Change-Id: I43bab4a823d61c56596e1fd5b1522de08b9674f2
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 0a8567f..d2ffaa7 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -441,7 +441,7 @@
     //
     // All sizes are specified in bytes, and the device, snapshot, COW partition and COW file sizes
     // must be a multiple of the sector size (512 bytes).
-    bool CreateSnapshot(LockedFile* lock, SnapshotStatus* status);
+    bool CreateSnapshot(LockedFile* lock, PartitionCowCreator* cow_creator, SnapshotStatus* status);
 
     // |name| should be the base partition name (e.g. "system_a"). Create the
     // backing COW image using the size previously passed to CreateSnapshot().
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index ebda430..b55d9a0 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -312,7 +312,8 @@
     return WriteUpdateState(lock.get(), UpdateState::Unverified);
 }
 
-bool SnapshotManager::CreateSnapshot(LockedFile* lock, SnapshotStatus* status) {
+bool SnapshotManager::CreateSnapshot(LockedFile* lock, PartitionCowCreator* cow_creator,
+                                     SnapshotStatus* status) {
     CHECK(lock);
     CHECK(lock->lock_mode() == LOCK_EX);
     CHECK(status);
@@ -353,7 +354,7 @@
     status->set_state(SnapshotState::CREATED);
     status->set_sectors_allocated(0);
     status->set_metadata_sectors(0);
-    status->set_compression_enabled(IsCompressionEnabled());
+    status->set_compression_enabled(cow_creator->compression_enabled);
 
     if (!WriteSnapshotStatus(lock, *status)) {
         PLOG(ERROR) << "Could not write snapshot status: " << status->name();
@@ -2584,6 +2585,9 @@
     // these devices.
     AutoDeviceList created_devices;
 
+    bool use_compression =
+            IsCompressionEnabled() && manifest.dynamic_partition_metadata().vabc_enabled();
+
     PartitionCowCreator cow_creator{
             .target_metadata = target_metadata.get(),
             .target_suffix = target_suffix,
@@ -2592,7 +2596,7 @@
             .current_suffix = current_suffix,
             .update = nullptr,
             .extra_extents = {},
-            .compression_enabled = IsCompressionEnabled(),
+            .compression_enabled = use_compression,
     };
 
     auto ret = CreateUpdateSnapshotsInternal(lock.get(), manifest, &cow_creator, &created_devices,
@@ -2744,7 +2748,7 @@
         }
 
         // Store these device sizes to snapshot status file.
-        if (!CreateSnapshot(lock, &cow_creator_ret->snapshot_status)) {
+        if (!CreateSnapshot(lock, cow_creator, &cow_creator_ret->snapshot_status)) {
             return Return::Error();
         }
         created_devices->EmplaceBack<AutoDeleteSnapshot>(this, lock, target_partition->name());
@@ -2857,11 +2861,6 @@
 
 bool SnapshotManager::MapUpdateSnapshot(const CreateLogicalPartitionParams& params,
                                         std::string* snapshot_path) {
-    if (IsCompressionEnabled()) {
-        LOG(ERROR) << "MapUpdateSnapshot cannot be used in compression mode.";
-        return false;
-    }
-
     auto lock = LockShared();
     if (!lock) return false;
     if (!UnmapPartitionWithSnapshot(lock.get(), params.GetPartitionName())) {
@@ -2870,6 +2869,15 @@
         return false;
     }
 
+    SnapshotStatus status;
+    if (!ReadSnapshotStatus(lock.get(), params.GetPartitionName(), &status)) {
+        return false;
+    }
+    if (status.compression_enabled()) {
+        LOG(ERROR) << "Cannot use MapUpdateSnapshot with compressed snapshots";
+        return false;
+    }
+
     SnapshotPaths paths;
     if (!MapPartitionWithSnapshot(lock.get(), params, SnapshotContext::Update, &paths)) {
         return false;
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index 4c209ec..0b8a03a 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -41,6 +41,7 @@
 
 #include <android/snapshot/snapshot.pb.h>
 #include <libsnapshot/test_helpers.h>
+#include "partition_cow_creator.h"
 #include "utility.h"
 
 // Mock classes are not used. Header included to ensure mocked class definition aligns with the
@@ -323,7 +324,10 @@
 
         DeltaArchiveManifest manifest;
 
-        auto group = manifest.mutable_dynamic_partition_metadata()->add_groups();
+        auto dynamic_partition_metadata = manifest.mutable_dynamic_partition_metadata();
+        dynamic_partition_metadata->set_vabc_enabled(IsCompressionEnabled());
+
+        auto group = dynamic_partition_metadata->add_groups();
         group->set_name("group");
         group->set_size(device_size * 2);
         group->add_partition_names("test_partition");
@@ -416,13 +420,16 @@
 TEST_F(SnapshotTest, CreateSnapshot) {
     ASSERT_TRUE(AcquireLock());
 
+    PartitionCowCreator cow_creator;
+    cow_creator.compression_enabled = IsCompressionEnabled();
+
     static const uint64_t kDeviceSize = 1024 * 1024;
     SnapshotStatus status;
     status.set_name("test-snapshot");
     status.set_device_size(kDeviceSize);
     status.set_snapshot_size(kDeviceSize);
     status.set_cow_file_size(kDeviceSize);
-    ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &status));
+    ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &cow_creator, &status));
     ASSERT_TRUE(CreateCowImage("test-snapshot"));
 
     std::vector<std::string> snapshots;
@@ -437,6 +444,7 @@
         ASSERT_EQ(status.state(), SnapshotState::CREATED);
         ASSERT_EQ(status.device_size(), kDeviceSize);
         ASSERT_EQ(status.snapshot_size(), kDeviceSize);
+        ASSERT_EQ(status.compression_enabled(), cow_creator.compression_enabled);
     }
 
     ASSERT_TRUE(sm->UnmapSnapshot(lock_.get(), "test-snapshot"));
@@ -447,13 +455,16 @@
 TEST_F(SnapshotTest, MapSnapshot) {
     ASSERT_TRUE(AcquireLock());
 
+    PartitionCowCreator cow_creator;
+    cow_creator.compression_enabled = IsCompressionEnabled();
+
     static const uint64_t kDeviceSize = 1024 * 1024;
     SnapshotStatus status;
     status.set_name("test-snapshot");
     status.set_device_size(kDeviceSize);
     status.set_snapshot_size(kDeviceSize);
     status.set_cow_file_size(kDeviceSize);
-    ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &status));
+    ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), &cow_creator, &status));
     ASSERT_TRUE(CreateCowImage("test-snapshot"));
 
     std::string base_device;
diff --git a/fs_mgr/libsnapshot/update_engine/update_metadata.proto b/fs_mgr/libsnapshot/update_engine/update_metadata.proto
index dda214e..4a97f81 100644
--- a/fs_mgr/libsnapshot/update_engine/update_metadata.proto
+++ b/fs_mgr/libsnapshot/update_engine/update_metadata.proto
@@ -73,6 +73,7 @@
 
 message DynamicPartitionMetadata {
     repeated DynamicPartitionGroup groups = 1;
+    optional bool vabc_enabled = 3;
 }
 
 message DeltaArchiveManifest {