libsnapshot: Use the compression algorithm specified in the DeltaArchiveManifest.
update_engine and libsnapshot must agree on CowOptions parameters,
otherwise the COW size estimation may be incorrect.
Bug: N/A
Test: vts_libsnapshot_test
apply OTA, snapshotctl dump
Change-Id: I219ae458dfa19e4b3c96360d3b847edb2a01ebc8
diff --git a/fs_mgr/libsnapshot/android/snapshot/snapshot.proto b/fs_mgr/libsnapshot/android/snapshot/snapshot.proto
index 42bff14..b4e92a2 100644
--- a/fs_mgr/libsnapshot/android/snapshot/snapshot.proto
+++ b/fs_mgr/libsnapshot/android/snapshot/snapshot.proto
@@ -46,7 +46,7 @@
SECOND_PHASE = 2;
}
-// Next: 11
+// Next: 12
message SnapshotStatus {
// Name of the snapshot. This is usually the name of the snapshotted
// logical partition; for example, "system_b".
@@ -102,6 +102,9 @@
// The old partition size (if none existed, this will be zero).
uint64 old_partition_size = 10;
+
+ // Compression algorithm (none, gz, or brotli).
+ string compression_algorithm = 11;
}
// Next: 8
diff --git a/fs_mgr/libsnapshot/partition_cow_creator.h b/fs_mgr/libsnapshot/partition_cow_creator.h
index 84372de..34b39ca 100644
--- a/fs_mgr/libsnapshot/partition_cow_creator.h
+++ b/fs_mgr/libsnapshot/partition_cow_creator.h
@@ -58,6 +58,7 @@
std::vector<ChromeOSExtent> extra_extents = {};
// True if compression is enabled.
bool compression_enabled = false;
+ std::string compression_algorithm;
struct Return {
SnapshotStatus snapshot_status;
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index cc2599d..ca4c265 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -359,6 +359,7 @@
status->set_sectors_allocated(0);
status->set_metadata_sectors(0);
status->set_compression_enabled(cow_creator->compression_enabled);
+ status->set_compression_algorithm(cow_creator->compression_algorithm);
if (!WriteSnapshotStatus(lock, *status)) {
PLOG(ERROR) << "Could not write snapshot status: " << status->name();
@@ -2660,9 +2661,20 @@
// these devices.
AutoDeviceList created_devices;
- bool use_compression = IsCompressionEnabled() &&
- manifest.dynamic_partition_metadata().vabc_enabled() &&
- !device_->IsRecovery();
+ const auto& dap_metadata = manifest.dynamic_partition_metadata();
+ bool use_compression =
+ IsCompressionEnabled() && dap_metadata.vabc_enabled() && !device_->IsRecovery();
+
+ std::string compression_algorithm;
+ if (use_compression) {
+ compression_algorithm = dap_metadata.vabc_compression_param();
+ if (compression_algorithm.empty()) {
+ // Older OTAs don't set an explicit compression type, so default to gz.
+ compression_algorithm = "gz";
+ }
+ } else {
+ compression_algorithm = "none";
+ }
PartitionCowCreator cow_creator{
.target_metadata = target_metadata.get(),
@@ -2673,6 +2685,7 @@
.update = nullptr,
.extra_extents = {},
.compression_enabled = use_compression,
+ .compression_algorithm = compression_algorithm,
};
auto ret = CreateUpdateSnapshotsInternal(lock.get(), manifest, &cow_creator, &created_devices,
@@ -2917,7 +2930,7 @@
return Return::Error();
}
- CowWriter writer(CowOptions{});
+ CowWriter writer(CowOptions{.compression = it->second.compression_algorithm()});
if (!writer.Initialize(fd) || !writer.Finalize()) {
LOG(ERROR) << "Could not initialize COW device for " << target_partition->name();
return Return::Error();
@@ -3024,7 +3037,7 @@
CHECK(lock);
CowOptions cow_options;
- cow_options.compression = "gz";
+ cow_options.compression = status.compression_algorithm();
cow_options.max_blocks = {status.device_size() / cow_options.block_size};
// Currently we don't support partial snapshots, since partition_cow_creator
@@ -3163,6 +3176,7 @@
ss << " cow file size (bytes): " << status.cow_file_size() << std::endl;
ss << " allocated sectors: " << status.sectors_allocated() << std::endl;
ss << " metadata sectors: " << status.metadata_sectors() << std::endl;
+ ss << " compression: " << status.compression_algorithm() << std::endl;
}
os << ss.rdbuf();
return ok;
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index bde4cca..25500b5 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -423,6 +423,11 @@
PartitionCowCreator cow_creator;
cow_creator.compression_enabled = IsCompressionEnabled();
+ if (cow_creator.compression_enabled) {
+ cow_creator.compression_algorithm = "gz";
+ } else {
+ cow_creator.compression_algorithm = "none";
+ }
static const uint64_t kDeviceSize = 1024 * 1024;
SnapshotStatus status;
@@ -446,6 +451,7 @@
ASSERT_EQ(status.device_size(), kDeviceSize);
ASSERT_EQ(status.snapshot_size(), kDeviceSize);
ASSERT_EQ(status.compression_enabled(), cow_creator.compression_enabled);
+ ASSERT_EQ(status.compression_algorithm(), cow_creator.compression_algorithm);
}
ASSERT_TRUE(sm->UnmapSnapshot(lock_.get(), "test-snapshot"));
@@ -576,6 +582,11 @@
SnapshotStatus status;
ASSERT_TRUE(init->ReadSnapshotStatus(lock_.get(), "test_partition_b", &status));
ASSERT_EQ(status.state(), SnapshotState::CREATED);
+ if (IsCompressionEnabled()) {
+ ASSERT_EQ(status.compression_algorithm(), "gz");
+ } else {
+ ASSERT_EQ(status.compression_algorithm(), "none");
+ }
DeviceMapper::TargetInfo target;
ASSERT_TRUE(init->IsSnapshotDevice("test_partition_b", &target));
diff --git a/fs_mgr/libsnapshot/update_engine/update_metadata.proto b/fs_mgr/libsnapshot/update_engine/update_metadata.proto
index 4a97f81..f31ee31 100644
--- a/fs_mgr/libsnapshot/update_engine/update_metadata.proto
+++ b/fs_mgr/libsnapshot/update_engine/update_metadata.proto
@@ -74,6 +74,7 @@
message DynamicPartitionMetadata {
repeated DynamicPartitionGroup groups = 1;
optional bool vabc_enabled = 3;
+ optional string vabc_compression_param = 4;
}
message DeltaArchiveManifest {