Merge "libsnapshot: Partially implement OpenSnapshotWriter."
diff --git a/fastboot/Android.bp b/fastboot/Android.bp
index fe05553..85a19e5 100644
--- a/fastboot/Android.bp
+++ b/fastboot/Android.bp
@@ -147,6 +147,7 @@
static_libs: [
"libgtest_prod",
"libhealthhalutils",
+ "libsnapshot_cow",
"libsnapshot_nobinder",
"update_metadata-protos",
],
diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp
index 6e81c8b..ad592e9 100644
--- a/fs_mgr/libsnapshot/Android.bp
+++ b/fs_mgr/libsnapshot/Android.bp
@@ -77,6 +77,7 @@
"snapshot_stats.cpp",
"snapshot_stub.cpp",
"snapshot_metadata_updater.cpp",
+ "snapshot_writer.cpp",
"partition_cow_creator.cpp",
"return.cpp",
"utility.cpp",
@@ -247,6 +248,7 @@
"libgmock",
"liblp",
"libsnapshot",
+ "libsnapshot_cow",
"libsnapshot_test_helpers",
"libsparse",
],
@@ -275,6 +277,7 @@
static_libs: [
"libfstab",
"libsnapshot",
+ "libsnapshot_cow",
"update_metadata-protos",
],
shared_libs: [
@@ -338,6 +341,7 @@
"libgmock", // from libsnapshot_test_helpers
"liblog",
"liblp",
+ "libsnapshot_cow",
"libsnapshot_test_helpers",
"libprotobuf-mutator",
],
diff --git a/fs_mgr/libsnapshot/cow_writer.cpp b/fs_mgr/libsnapshot/cow_writer.cpp
index 70fdac1..f96f174 100644
--- a/fs_mgr/libsnapshot/cow_writer.cpp
+++ b/fs_mgr/libsnapshot/cow_writer.cpp
@@ -32,6 +32,9 @@
static_assert(sizeof(off_t) == sizeof(uint64_t));
+using android::base::borrowed_fd;
+using android::base::unique_fd;
+
bool ICowWriter::AddCopy(uint64_t new_block, uint64_t old_block) {
if (!ValidateNewBlock(new_block)) {
return false;
@@ -98,12 +101,12 @@
return true;
}
-bool CowWriter::Initialize(android::base::unique_fd&& fd, OpenMode mode) {
+bool CowWriter::Initialize(unique_fd&& fd, OpenMode mode) {
owned_fd_ = std::move(fd);
- return Initialize(android::base::borrowed_fd{owned_fd_}, mode);
+ return Initialize(borrowed_fd{owned_fd_}, mode);
}
-bool CowWriter::Initialize(android::base::borrowed_fd fd, OpenMode mode) {
+bool CowWriter::Initialize(borrowed_fd fd, OpenMode mode) {
fd_ = fd;
if (!ParseOptions()) {
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
index 245da0c..2bc0171 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
@@ -58,6 +58,9 @@
// Return number of bytes the cow image occupies on disk.
virtual uint64_t GetCowSize() = 0;
+ // Returns true if AddCopy() operations are supported.
+ virtual bool SupportsCopyOperation() const { return true; }
+
const CowOptions& options() { return options_; }
protected:
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/mock_snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/mock_snapshot.h
index eb6ad05..13f19aa 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/mock_snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/mock_snapshot.h
@@ -38,9 +38,7 @@
(const android::fs_mgr::CreateLogicalPartitionParams& params,
std::string* snapshot_path),
(override));
- MOCK_METHOD(std::unique_ptr<ICowWriter>, OpenSnapshotWriter,
- (const android::fs_mgr::CreateLogicalPartitionParams& params), (override));
- MOCK_METHOD(std::unique_ptr<FileDescriptor>, OpenSnapshotReader,
+ MOCK_METHOD(std::unique_ptr<ISnapshotWriter>, OpenSnapshotWriter,
(const android::fs_mgr::CreateLogicalPartitionParams& params), (override));
MOCK_METHOD(bool, UnmapUpdateSnapshot, (const std::string& target_partition_name), (override));
MOCK_METHOD(bool, NeedSnapshotsInFirstStageMount, (), (override));
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 6fef58a..1bc972e 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -35,8 +35,8 @@
#include <update_engine/update_metadata.pb.h>
#include <libsnapshot/auto_device.h>
-#include <libsnapshot/cow_writer.h>
#include <libsnapshot/return.h>
+#include <libsnapshot/snapshot_writer.h>
#ifndef FRIEND_TEST
#define FRIEND_TEST(test_set_name, individual_test) \
@@ -44,10 +44,6 @@
#define DEFINED_FRIEND_TEST
#endif
-namespace chromeos_update_engine {
-class FileDescriptor;
-} // namespace chromeos_update_engine
-
namespace android {
namespace fiemap {
@@ -110,8 +106,6 @@
};
virtual ~ISnapshotManager() = default;
- using FileDescriptor = chromeos_update_engine::FileDescriptor;
-
// Begin an update. This must be called before creating any snapshots. It
// will fail if GetUpdateState() != None.
virtual bool BeginUpdate() = 0;
@@ -187,19 +181,14 @@
virtual bool MapUpdateSnapshot(const android::fs_mgr::CreateLogicalPartitionParams& params,
std::string* snapshot_path) = 0;
- // Create an ICowWriter to build a snapshot against a target partition. The partition name must
- // be suffixed.
- virtual std::unique_ptr<ICowWriter> OpenSnapshotWriter(
- const android::fs_mgr::CreateLogicalPartitionParams& params) = 0;
-
- // Open a snapshot for reading. A file-like interface is provided through the FileDescriptor.
- // In this mode, writes are not supported. The partition name must be suffixed.
- virtual std::unique_ptr<FileDescriptor> OpenSnapshotReader(
+ // Create an ISnapshotWriter to build a snapshot against a target partition. The partition name
+ // must be suffixed.
+ virtual std::unique_ptr<ISnapshotWriter> OpenSnapshotWriter(
const android::fs_mgr::CreateLogicalPartitionParams& params) = 0;
// Unmap a snapshot device or CowWriter that was previously opened with MapUpdateSnapshot,
- // OpenSnapshotWriter, or OpenSnapshotReader. All outstanding open descriptors, writers,
- // or readers must be deleted before this is called.
+ // OpenSnapshotWriter. All outstanding open descriptors, writers, or
+ // readers must be deleted before this is called.
virtual bool UnmapUpdateSnapshot(const std::string& target_partition_name) = 0;
// If this returns true, first-stage mount must call
@@ -310,9 +299,7 @@
Return CreateUpdateSnapshots(const DeltaArchiveManifest& manifest) override;
bool MapUpdateSnapshot(const CreateLogicalPartitionParams& params,
std::string* snapshot_path) override;
- std::unique_ptr<ICowWriter> OpenSnapshotWriter(
- const android::fs_mgr::CreateLogicalPartitionParams& params) override;
- std::unique_ptr<FileDescriptor> OpenSnapshotReader(
+ std::unique_ptr<ISnapshotWriter> OpenSnapshotWriter(
const android::fs_mgr::CreateLogicalPartitionParams& params) override;
bool UnmapUpdateSnapshot(const std::string& target_partition_name) override;
bool NeedSnapshotsInFirstStageMount() override;
@@ -532,9 +519,39 @@
std::string GetSnapshotDeviceName(const std::string& snapshot_name,
const SnapshotStatus& status);
+ // Reason for calling MapPartitionWithSnapshot.
+ enum class SnapshotContext {
+ // For writing or verification (during update_engine).
+ Update,
+
+ // For mounting a full readable device.
+ Mount,
+ };
+
+ struct SnapshotPaths {
+ // Target/base device (eg system_b), always present.
+ std::string target_device;
+
+ // COW path (eg system_cow). Not present if no COW is needed.
+ std::string cow_device;
+
+ // dm-snapshot instance. Not present in Update mode for VABC.
+ std::string snapshot_device;
+ };
+
+ // Helpers for OpenSnapshotWriter.
+ std::unique_ptr<ISnapshotWriter> OpenCompressedSnapshotWriter(LockedFile* lock,
+ const std::string& partition_name,
+ const SnapshotStatus& status,
+ const SnapshotPaths& paths);
+ std::unique_ptr<ISnapshotWriter> OpenKernelSnapshotWriter(LockedFile* lock,
+ const std::string& partition_name,
+ const SnapshotStatus& status,
+ const SnapshotPaths& paths);
+
// Map the base device, COW devices, and snapshot device.
bool MapPartitionWithSnapshot(LockedFile* lock, CreateLogicalPartitionParams params,
- std::string* path);
+ SnapshotContext context, SnapshotPaths* paths);
// Map the COW devices, including the partition in super and the images.
// |params|:
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot_stub.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot_stub.h
index 149f463..cda2bee 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot_stub.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot_stub.h
@@ -36,9 +36,7 @@
const chromeos_update_engine::DeltaArchiveManifest& manifest) override;
bool MapUpdateSnapshot(const android::fs_mgr::CreateLogicalPartitionParams& params,
std::string* snapshot_path) override;
- std::unique_ptr<ICowWriter> OpenSnapshotWriter(
- const android::fs_mgr::CreateLogicalPartitionParams& params) override;
- std::unique_ptr<FileDescriptor> OpenSnapshotReader(
+ std::unique_ptr<ISnapshotWriter> OpenSnapshotWriter(
const android::fs_mgr::CreateLogicalPartitionParams& params) override;
bool UnmapUpdateSnapshot(const std::string& target_partition_name) override;
bool NeedSnapshotsInFirstStageMount() override;
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot_writer.h
new file mode 100644
index 0000000..bf57a00
--- /dev/null
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot_writer.h
@@ -0,0 +1,68 @@
+// 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 <android-base/unique_fd.h>
+
+#include <libsnapshot/cow_writer.h>
+
+namespace chromeos_update_engine {
+class FileDescriptor;
+} // namespace chromeos_update_engine
+
+namespace android {
+namespace snapshot {
+
+class ISnapshotWriter : public ICowWriter {
+ public:
+ using FileDescriptor = chromeos_update_engine::FileDescriptor;
+
+ explicit ISnapshotWriter(const CowOptions& options);
+
+ // Set the source device. This is used for AddCopy() operations, if the
+ // underlying writer needs the original bytes (for example if backed by
+ // dm-snapshot or if writing directly to an unsnapshotted region).
+ void SetSourceDevice(android::base::unique_fd&& source_fd);
+
+ virtual std::unique_ptr<FileDescriptor> OpenReader() = 0;
+
+ protected:
+ android::base::unique_fd source_fd_;
+};
+
+// Write directly to a dm-snapshot device.
+class OnlineKernelSnapshotWriter : public ISnapshotWriter {
+ public:
+ OnlineKernelSnapshotWriter(const CowOptions& options);
+
+ // Set the device used for all writes.
+ void SetSnapshotDevice(android::base::unique_fd&& snapshot_fd, uint64_t cow_size);
+
+ bool Flush() override;
+ uint64_t GetCowSize() override { return cow_size_; }
+ virtual std::unique_ptr<FileDescriptor> OpenReader() override;
+
+ protected:
+ bool EmitRawBlocks(uint64_t new_block_start, const void* data, size_t size) override;
+ bool EmitZeroBlocks(uint64_t new_block_start, uint64_t num_blocks) override;
+ bool EmitCopy(uint64_t new_block, uint64_t old_block) override;
+
+ private:
+ android::base::unique_fd snapshot_fd_;
+ uint64_t cow_size_ = 0;
+};
+
+} // namespace snapshot
+} // namespace android
diff --git a/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h b/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h
index 8e369b0..197aeaa 100644
--- a/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h
+++ b/fs_mgr/libsnapshot/include_test/libsnapshot/test_helpers.h
@@ -144,6 +144,7 @@
// Expect space of |path| is multiple of 4K.
bool WriteRandomData(const std::string& path, std::optional<size_t> expect_size = std::nullopt,
std::string* hash = nullptr);
+bool WriteRandomData(ICowWriter* writer, std::string* hash = nullptr);
std::optional<std::string> GetHash(const std::string& path);
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 0904fc7..2df2c94 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -15,6 +15,7 @@
#include <libsnapshot/snapshot.h>
#include <dirent.h>
+#include <fcntl.h>
#include <math.h>
#include <sys/file.h>
#include <sys/types.h>
@@ -1569,8 +1570,8 @@
.partition_opener = &opener,
.timeout_ms = timeout_ms,
};
- std::string ignore_path;
- if (!MapPartitionWithSnapshot(lock.get(), std::move(params), &ignore_path)) {
+ if (!MapPartitionWithSnapshot(lock.get(), std::move(params), SnapshotContext::Mount,
+ nullptr)) {
return false;
}
}
@@ -1598,11 +1599,10 @@
bool SnapshotManager::MapPartitionWithSnapshot(LockedFile* lock,
CreateLogicalPartitionParams params,
- std::string* path) {
+ SnapshotContext context, SnapshotPaths* paths) {
auto begin = std::chrono::steady_clock::now();
CHECK(lock);
- path->clear();
if (params.GetPartitionName() != params.GetDeviceName()) {
LOG(ERROR) << "Mapping snapshot with a different name is unsupported: partition_name = "
@@ -1683,8 +1683,11 @@
}
created_devices.EmplaceBack<AutoUnmapDevice>(&dm, params.GetDeviceName());
+ if (paths) {
+ paths->target_device = base_path;
+ }
+
if (!live_snapshot_status.has_value()) {
- *path = base_path;
created_devices.Release();
return true;
}
@@ -1711,21 +1714,33 @@
LOG(ERROR) << "Could not determine major/minor for: " << cow_name;
return false;
}
+ if (paths) {
+ paths->cow_device = cow_device;
+ }
remaining_time = GetRemainingTime(params.timeout_ms, begin);
if (remaining_time.count() < 0) return false;
+ if (context == SnapshotContext::Update && IsCompressionEnabled()) {
+ // Stop here, we can't run dm-user yet, the COW isn't built.
+ return true;
+ }
+
+ std::string path;
if (!MapSnapshot(lock, params.GetPartitionName(), base_device, cow_device, remaining_time,
- path)) {
+ &path)) {
LOG(ERROR) << "Could not map snapshot for partition: " << params.GetPartitionName();
return false;
}
// No need to add params.GetPartitionName() to created_devices since it is immediately released.
+ if (paths) {
+ paths->snapshot_device = path;
+ }
+
created_devices.Release();
- LOG(INFO) << "Mapped " << params.GetPartitionName() << " as snapshot device at " << *path;
-
+ LOG(INFO) << "Mapped " << params.GetPartitionName() << " as snapshot device at " << path;
return true;
}
@@ -2438,23 +2453,85 @@
<< params.GetPartitionName();
return false;
}
- return MapPartitionWithSnapshot(lock.get(), params, snapshot_path);
+
+ SnapshotPaths paths;
+ if (!MapPartitionWithSnapshot(lock.get(), params, SnapshotContext::Update, &paths)) {
+ return false;
+ }
+
+ if (!paths.snapshot_device.empty()) {
+ *snapshot_path = paths.snapshot_device;
+ } else {
+ *snapshot_path = paths.target_device;
+ }
+ DCHECK(!snapshot_path->empty());
+ return true;
}
-std::unique_ptr<ICowWriter> SnapshotManager::OpenSnapshotWriter(
+std::unique_ptr<ISnapshotWriter> SnapshotManager::OpenSnapshotWriter(
const android::fs_mgr::CreateLogicalPartitionParams& params) {
- (void)params;
+ // First unmap any existing mapping.
+ auto lock = LockShared();
+ if (!lock) return nullptr;
+ if (!UnmapPartitionWithSnapshot(lock.get(), params.GetPartitionName())) {
+ LOG(ERROR) << "Cannot unmap existing snapshot before re-mapping it: "
+ << params.GetPartitionName();
+ return nullptr;
+ }
- LOG(ERROR) << "OpenSnapshotWriter not yet implemented";
+ SnapshotPaths paths;
+ if (!MapPartitionWithSnapshot(lock.get(), params, SnapshotContext::Update, &paths)) {
+ return nullptr;
+ }
+
+ SnapshotStatus status;
+ if (!paths.cow_device.empty()) {
+ if (!ReadSnapshotStatus(lock.get(), params.GetPartitionName(), &status)) {
+ return nullptr;
+ }
+ } else {
+ // Currently, partition_cow_creator always creates snapshots. The
+ // reason is that if partition X shrinks while partition Y grows, we
+ // cannot bindly write to the newly freed extents in X. This would
+ // make the old slot unusable. So, the entire size of the target
+ // partition is currently considered snapshottable.
+ LOG(ERROR) << "No snapshot available for partition " << params.GetPartitionName();
+ return nullptr;
+ }
+
+ if (IsCompressionEnabled()) {
+ return OpenCompressedSnapshotWriter(lock.get(), params.GetPartitionName(), status, paths);
+ }
+ return OpenKernelSnapshotWriter(lock.get(), params.GetPartitionName(), status, paths);
+}
+
+std::unique_ptr<ISnapshotWriter> SnapshotManager::OpenCompressedSnapshotWriter(
+ LockedFile*, const std::string&, const SnapshotStatus&, const SnapshotPaths&) {
+ LOG(ERROR) << "OpenSnapshotWriter not yet implemented for compression";
return nullptr;
}
-std::unique_ptr<FileDescriptor> SnapshotManager::OpenSnapshotReader(
- const android::fs_mgr::CreateLogicalPartitionParams& params) {
- (void)params;
+std::unique_ptr<ISnapshotWriter> SnapshotManager::OpenKernelSnapshotWriter(
+ LockedFile* lock, [[maybe_unused]] const std::string& partition_name,
+ const SnapshotStatus& status, const SnapshotPaths& paths) {
+ CHECK(lock);
- LOG(ERROR) << "OpenSnapshotReader not yet implemented";
- return nullptr;
+ CowOptions cow_options;
+ cow_options.max_blocks = {status.device_size() / cow_options.block_size};
+
+ auto writer = std::make_unique<OnlineKernelSnapshotWriter>(cow_options);
+
+ std::string path = paths.snapshot_device.empty() ? paths.target_device : paths.snapshot_device;
+ unique_fd fd(open(path.c_str(), O_RDWR | O_CLOEXEC));
+ if (fd < 0) {
+ PLOG(ERROR) << "open failed: " << path;
+ return nullptr;
+ }
+
+ uint64_t cow_size = status.cow_partition_size() + status.cow_file_size();
+ writer->SetSnapshotDevice(std::move(fd), cow_size);
+
+ return writer;
}
bool SnapshotManager::UnmapUpdateSnapshot(const std::string& target_partition_name) {
diff --git a/fs_mgr/libsnapshot/snapshot_stub.cpp b/fs_mgr/libsnapshot/snapshot_stub.cpp
index 8ae6305..41f5da4 100644
--- a/fs_mgr/libsnapshot/snapshot_stub.cpp
+++ b/fs_mgr/libsnapshot/snapshot_stub.cpp
@@ -130,13 +130,7 @@
return &snapshot_merge_stats;
}
-std::unique_ptr<ICowWriter> SnapshotManagerStub::OpenSnapshotWriter(
- const CreateLogicalPartitionParams&) {
- LOG(ERROR) << __FUNCTION__ << " should never be called.";
- return nullptr;
-}
-
-std::unique_ptr<FileDescriptor> SnapshotManagerStub::OpenSnapshotReader(
+std::unique_ptr<ISnapshotWriter> SnapshotManagerStub::OpenSnapshotWriter(
const CreateLogicalPartitionParams&) {
LOG(ERROR) << __FUNCTION__ << " should never be called.";
return nullptr;
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index 6ff935b..77226ad 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -80,6 +80,7 @@
std::string fake_super;
void MountMetadata();
+bool IsCompressionEnabled();
class SnapshotTest : public ::testing::Test {
public:
@@ -892,42 +893,78 @@
return AssertionSuccess();
}
- AssertionResult MapUpdateSnapshot(const std::string& name, std::string* path = nullptr) {
- std::string real_path;
- if (!sm->MapUpdateSnapshot(
- CreateLogicalPartitionParams{
- .block_device = fake_super,
- .metadata_slot = 1,
- .partition_name = name,
- .timeout_ms = 10s,
- .partition_opener = opener_.get(),
- },
- &real_path)) {
- return AssertionFailure() << "Unable to map snapshot " << name;
+ 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 (path) {
- *path = real_path;
+
+ if (writer) {
+ *writer = std::move(result);
}
- return AssertionSuccess() << "Mapped snapshot " << name << " to " << real_path;
+ return AssertionSuccess();
}
- AssertionResult WriteSnapshotAndHash(const std::string& name,
- std::optional<size_t> size = std::nullopt) {
- std::string path;
- auto res = MapUpdateSnapshot(name, &path);
- if (!res) {
- return res;
+ 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) {
+ if (IsCompressionEnabled()) {
+ std::unique_ptr<ICowWriter> writer;
+ return MapUpdateSnapshot(name, &writer);
+ } else {
+ std::string path;
+ return MapUpdateSnapshot(name, &path);
+ }
+ }
+
+ AssertionResult WriteSnapshotAndHash(const std::string& name) {
+ if (IsCompressionEnabled()) {
+ std::unique_ptr<ICowWriter> writer;
+ auto res = MapUpdateSnapshot(name, &writer);
+ if (!res) {
+ return res;
+ }
+ if (!WriteRandomData(writer.get(), &hashes_[name])) {
+ return AssertionFailure() << "Unable to write random data to snapshot " << name;
+ }
+ } else {
+ std::string path;
+ auto res = MapUpdateSnapshot(name, &path);
+ if (!res) {
+ return res;
+ }
+ if (!WriteRandomData(path, std::nullopt, &hashes_[name])) {
+ return AssertionFailure() << "Unable to write random data to snapshot " << name;
+ }
}
- std::string size_string = size ? (std::to_string(*size) + " bytes") : "";
+ // Make sure updates to one device are seen by all devices.
+ sync();
- if (!WriteRandomData(path, size, &hashes_[name])) {
- return AssertionFailure() << "Unable to write " << size_string << " to " << path
- << " for partition " << name;
- }
-
- return AssertionSuccess() << "Written " << size_string << " to " << path
- << " for snapshot partition " << name
+ return AssertionSuccess() << "Written random data to snapshot " << name
<< ", hash: " << hashes_[name];
}
@@ -1003,7 +1040,7 @@
// Write some data to target partitions.
for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
- ASSERT_TRUE(WriteSnapshotAndHash(name, partition_size));
+ ASSERT_TRUE(WriteSnapshotAndHash(name));
}
// Assert that source partitions aren't affected.
@@ -1406,6 +1443,10 @@
MetadataMountedTest().TearDown();
}
+bool IsCompressionEnabled() {
+ return android::base::GetBoolProperty("ro.virtual_ab.compression.enabled", false);
+}
+
TEST_F(MetadataMountedTest, Android) {
auto device = sm->EnsureMetadataMounted();
EXPECT_NE(nullptr, device);
@@ -1623,7 +1664,7 @@
// Map and write some data to target partition.
ASSERT_TRUE(MapUpdateSnapshots({"vnd_b", "prd_b"}));
- ASSERT_TRUE(WriteSnapshotAndHash("sys_b", partition_size));
+ ASSERT_TRUE(WriteSnapshotAndHash("sys_b"));
// Finish update.
ASSERT_TRUE(sm->FinishedSnapshotWrites(false));
@@ -1655,7 +1696,7 @@
// Map and write some data to target partitions.
ASSERT_TRUE(MapUpdateSnapshots({"vnd_b", "prd_b"}));
- ASSERT_TRUE(WriteSnapshotAndHash("sys_b", actual_write_size));
+ ASSERT_TRUE(WriteSnapshotAndHash("sys_b"));
std::vector<android::dm::DeviceMapper::TargetInfo> table;
ASSERT_TRUE(DeviceMapper::Instance().GetTableStatus("sys_b", &table));
diff --git a/fs_mgr/libsnapshot/snapshot_writer.cpp b/fs_mgr/libsnapshot/snapshot_writer.cpp
new file mode 100644
index 0000000..1958f18
--- /dev/null
+++ b/fs_mgr/libsnapshot/snapshot_writer.cpp
@@ -0,0 +1,91 @@
+//
+// 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 <libsnapshot/snapshot_writer.h>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <payload_consumer/file_descriptor.h>
+
+namespace android {
+namespace snapshot {
+
+using chromeos_update_engine::FileDescriptor;
+
+ISnapshotWriter::ISnapshotWriter(const CowOptions& options) : ICowWriter(options) {}
+
+void ISnapshotWriter::SetSourceDevice(android::base::unique_fd&& source_fd) {
+ source_fd_ = std::move(source_fd);
+}
+
+OnlineKernelSnapshotWriter::OnlineKernelSnapshotWriter(const CowOptions& options)
+ : ISnapshotWriter(options) {}
+
+void OnlineKernelSnapshotWriter::SetSnapshotDevice(android::base::unique_fd&& snapshot_fd,
+ uint64_t cow_size) {
+ snapshot_fd_ = std::move(snapshot_fd);
+ cow_size_ = cow_size;
+}
+
+bool OnlineKernelSnapshotWriter::Flush() {
+ if (fsync(snapshot_fd_.get()) < 0) {
+ PLOG(ERROR) << "fsync";
+ return false;
+ }
+ return true;
+}
+
+bool OnlineKernelSnapshotWriter::EmitRawBlocks(uint64_t new_block_start, const void* data,
+ size_t size) {
+ uint64_t offset = new_block_start * options_.block_size;
+ if (lseek(snapshot_fd_.get(), offset, SEEK_SET) < 0) {
+ PLOG(ERROR) << "EmitRawBlocks lseek to offset " << offset;
+ return false;
+ }
+ if (!android::base::WriteFully(snapshot_fd_, data, size)) {
+ PLOG(ERROR) << "EmitRawBlocks write";
+ return false;
+ }
+ return true;
+}
+
+bool OnlineKernelSnapshotWriter::EmitZeroBlocks(uint64_t new_block_start, uint64_t num_blocks) {
+ std::string zeroes(options_.block_size, 0);
+ for (uint64_t i = 0; i < num_blocks; i++) {
+ if (!EmitRawBlocks(new_block_start + i, zeroes.data(), zeroes.size())) {
+ return false;
+ }
+ }
+ return true;
+}
+
+bool OnlineKernelSnapshotWriter::EmitCopy(uint64_t new_block, uint64_t old_block) {
+ std::string buffer(options_.block_size, 0);
+ uint64_t offset = old_block * options_.block_size;
+ if (!android::base::ReadFullyAtOffset(source_fd_, buffer.data(), buffer.size(), offset)) {
+ PLOG(ERROR) << "EmitCopy read";
+ return false;
+ }
+ return EmitRawBlocks(new_block, buffer.data(), buffer.size());
+}
+
+std::unique_ptr<FileDescriptor> OnlineKernelSnapshotWriter::OpenReader() {
+ LOG(ERROR) << "OnlineKernelSnapshotWriter::OpenReader not yet implemented";
+ return nullptr;
+}
+
+} // namespace snapshot
+} // namespace android
diff --git a/fs_mgr/libsnapshot/test_helpers.cpp b/fs_mgr/libsnapshot/test_helpers.cpp
index b07bf91..6104c82 100644
--- a/fs_mgr/libsnapshot/test_helpers.cpp
+++ b/fs_mgr/libsnapshot/test_helpers.cpp
@@ -127,6 +127,48 @@
return true;
}
+bool WriteRandomData(ICowWriter* writer, std::string* hash) {
+ unique_fd rand(open("/dev/urandom", O_RDONLY));
+ if (rand < 0) {
+ PLOG(ERROR) << "open /dev/urandom";
+ return false;
+ }
+
+ SHA256_CTX ctx;
+ if (hash) {
+ SHA256_Init(&ctx);
+ }
+
+ if (!writer->options().max_blocks) {
+ LOG(ERROR) << "CowWriter must specify maximum number of blocks";
+ return false;
+ }
+ uint64_t num_blocks = writer->options().max_blocks.value();
+
+ size_t block_size = writer->options().block_size;
+ std::string block(block_size, '\0');
+ for (uint64_t i = 0; i < num_blocks; i++) {
+ if (!ReadFully(rand, block.data(), block.size())) {
+ PLOG(ERROR) << "read /dev/urandom";
+ return false;
+ }
+ if (!writer->AddRawBlocks(i, block.data(), block.size())) {
+ LOG(ERROR) << "Failed to add raw block " << i;
+ return false;
+ }
+ if (hash) {
+ SHA256_Update(&ctx, block.data(), block.size());
+ }
+ }
+
+ if (hash) {
+ uint8_t out[32];
+ SHA256_Final(out, &ctx);
+ *hash = ToHexString(out, sizeof(out));
+ }
+ return true;
+}
+
std::optional<std::string> GetHash(const std::string& path) {
std::string content;
if (!android::base::ReadFileToString(path, &content, true)) {
diff --git a/init/Android.bp b/init/Android.bp
index 13b1876..19ba21b 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -129,6 +129,7 @@
"libprotobuf-cpp-lite",
"libpropertyinfoserializer",
"libpropertyinfoparser",
+ "libsnapshot_cow",
"libsnapshot_init",
"libxml2",
"lib_apex_manifest_proto_lite",
diff --git a/init/Android.mk b/init/Android.mk
index da94daf..998e0fd 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -112,6 +112,7 @@
libmodprobe \
libext2_uuid \
libprotobuf-cpp-lite \
+ libsnapshot_cow \
libsnapshot_init \
update_metadata-protos \