Merge changes Ie93d09b3,I56f0218f,I3c9a3855 am: 4872b73b9e am: 5487958d34
Original change: https://android-review.googlesource.com/c/platform/system/core/+/1673893
Change-Id: I603124ccabb0f3dd858a1ff1f7d3811c815aa9bf
diff --git a/fs_mgr/libsnapshot/cow_api_test.cpp b/fs_mgr/libsnapshot/cow_api_test.cpp
index 5d63220..b75b154 100644
--- a/fs_mgr/libsnapshot/cow_api_test.cpp
+++ b/fs_mgr/libsnapshot/cow_api_test.cpp
@@ -25,6 +25,10 @@
#include <libsnapshot/cow_reader.h>
#include <libsnapshot/cow_writer.h>
+using testing::AssertionFailure;
+using testing::AssertionResult;
+using testing::AssertionSuccess;
+
namespace android {
namespace snapshot {
@@ -781,6 +785,202 @@
ASSERT_TRUE(reader.Parse(cow_->fd));
}
+AssertionResult WriteDataBlock(CowWriter* writer, uint64_t new_block, std::string data) {
+ data.resize(writer->options().block_size, '\0');
+ if (!writer->AddRawBlocks(new_block, data.data(), data.size())) {
+ return AssertionFailure() << "Failed to add raw block";
+ }
+ return AssertionSuccess();
+}
+
+AssertionResult CompareDataBlock(CowReader* reader, const CowOperation& op,
+ const std::string& data) {
+ CowHeader header;
+ reader->GetHeader(&header);
+
+ std::string cmp = data;
+ cmp.resize(header.block_size, '\0');
+
+ StringSink sink;
+ if (!reader->ReadData(op, &sink)) {
+ return AssertionFailure() << "Failed to read data block";
+ }
+ if (cmp != sink.stream()) {
+ return AssertionFailure() << "Data blocks did not match, expected " << cmp << ", got "
+ << sink.stream();
+ }
+
+ return AssertionSuccess();
+}
+
+TEST_F(CowTest, ResumeMidCluster) {
+ CowOptions options;
+ options.cluster_ops = 7;
+ auto writer = std::make_unique<CowWriter>(options);
+ ASSERT_TRUE(writer->Initialize(cow_->fd));
+
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 1, "Block 1"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 2, "Block 2"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 3, "Block 3"));
+ ASSERT_TRUE(writer->AddLabel(1));
+ ASSERT_TRUE(writer->Finalize());
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 4, "Block 4"));
+ ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+ writer = std::make_unique<CowWriter>(options);
+ ASSERT_TRUE(writer->InitializeAppend(cow_->fd, 1));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 4, "Block 4"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 5, "Block 5"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 6, "Block 6"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 7, "Block 7"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 8, "Block 8"));
+ ASSERT_TRUE(writer->AddLabel(2));
+ ASSERT_TRUE(writer->Finalize());
+ ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+ CowReader reader;
+ ASSERT_TRUE(reader.Parse(cow_->fd));
+
+ auto iter = reader.GetOpIter();
+ size_t num_replace = 0;
+ size_t max_in_cluster = 0;
+ size_t num_in_cluster = 0;
+ size_t num_clusters = 0;
+ while (!iter->Done()) {
+ const auto& op = iter->Get();
+
+ num_in_cluster++;
+ max_in_cluster = std::max(max_in_cluster, num_in_cluster);
+
+ if (op.type == kCowReplaceOp) {
+ num_replace++;
+
+ ASSERT_EQ(op.new_block, num_replace);
+ ASSERT_TRUE(CompareDataBlock(&reader, op, "Block " + std::to_string(num_replace)));
+ } else if (op.type == kCowClusterOp) {
+ num_in_cluster = 0;
+ num_clusters++;
+ }
+
+ iter->Next();
+ }
+ ASSERT_EQ(num_replace, 8);
+ ASSERT_EQ(max_in_cluster, 7);
+ ASSERT_EQ(num_clusters, 2);
+}
+
+TEST_F(CowTest, ResumeEndCluster) {
+ CowOptions options;
+ int cluster_ops = 5;
+ options.cluster_ops = cluster_ops;
+ auto writer = std::make_unique<CowWriter>(options);
+ ASSERT_TRUE(writer->Initialize(cow_->fd));
+
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 1, "Block 1"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 2, "Block 2"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 3, "Block 3"));
+ ASSERT_TRUE(writer->AddLabel(1));
+ ASSERT_TRUE(writer->Finalize());
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 4, "Block 4"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 5, "Block 5"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 6, "Block 6"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 7, "Block 7"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 8, "Block 8"));
+ ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+ writer = std::make_unique<CowWriter>(options);
+ ASSERT_TRUE(writer->InitializeAppend(cow_->fd, 1));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 4, "Block 4"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 5, "Block 5"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 6, "Block 6"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 7, "Block 7"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 8, "Block 8"));
+ ASSERT_TRUE(writer->AddLabel(2));
+ ASSERT_TRUE(writer->Finalize());
+ ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+ CowReader reader;
+ ASSERT_TRUE(reader.Parse(cow_->fd));
+
+ auto iter = reader.GetOpIter();
+ size_t num_replace = 0;
+ size_t max_in_cluster = 0;
+ size_t num_in_cluster = 0;
+ size_t num_clusters = 0;
+ while (!iter->Done()) {
+ const auto& op = iter->Get();
+
+ num_in_cluster++;
+ max_in_cluster = std::max(max_in_cluster, num_in_cluster);
+
+ if (op.type == kCowReplaceOp) {
+ num_replace++;
+
+ ASSERT_EQ(op.new_block, num_replace);
+ ASSERT_TRUE(CompareDataBlock(&reader, op, "Block " + std::to_string(num_replace)));
+ } else if (op.type == kCowClusterOp) {
+ num_in_cluster = 0;
+ num_clusters++;
+ }
+
+ iter->Next();
+ }
+ ASSERT_EQ(num_replace, 8);
+ ASSERT_EQ(max_in_cluster, cluster_ops);
+ ASSERT_EQ(num_clusters, 3);
+}
+
+TEST_F(CowTest, DeleteMidCluster) {
+ CowOptions options;
+ options.cluster_ops = 7;
+ auto writer = std::make_unique<CowWriter>(options);
+ ASSERT_TRUE(writer->Initialize(cow_->fd));
+
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 1, "Block 1"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 2, "Block 2"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 3, "Block 3"));
+ ASSERT_TRUE(writer->AddLabel(1));
+ ASSERT_TRUE(writer->Finalize());
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 4, "Block 4"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 5, "Block 5"));
+ ASSERT_TRUE(WriteDataBlock(writer.get(), 6, "Block 6"));
+ ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+ writer = std::make_unique<CowWriter>(options);
+ ASSERT_TRUE(writer->InitializeAppend(cow_->fd, 1));
+ ASSERT_TRUE(writer->Finalize());
+ ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+ CowReader reader;
+ ASSERT_TRUE(reader.Parse(cow_->fd));
+
+ auto iter = reader.GetOpIter();
+ size_t num_replace = 0;
+ size_t max_in_cluster = 0;
+ size_t num_in_cluster = 0;
+ size_t num_clusters = 0;
+ while (!iter->Done()) {
+ const auto& op = iter->Get();
+
+ num_in_cluster++;
+ max_in_cluster = std::max(max_in_cluster, num_in_cluster);
+ if (op.type == kCowReplaceOp) {
+ num_replace++;
+
+ ASSERT_EQ(op.new_block, num_replace);
+ ASSERT_TRUE(CompareDataBlock(&reader, op, "Block " + std::to_string(num_replace)));
+ } else if (op.type == kCowClusterOp) {
+ num_in_cluster = 0;
+ num_clusters++;
+ }
+
+ iter->Next();
+ }
+ ASSERT_EQ(num_replace, 3);
+ ASSERT_EQ(max_in_cluster, 5); // 3 data, 1 label, 1 cluster op
+ ASSERT_EQ(num_clusters, 1);
+}
+
} // namespace snapshot
} // namespace android
diff --git a/fs_mgr/libsnapshot/cow_writer.cpp b/fs_mgr/libsnapshot/cow_writer.cpp
index 59f6d6f..645ae9d 100644
--- a/fs_mgr/libsnapshot/cow_writer.cpp
+++ b/fs_mgr/libsnapshot/cow_writer.cpp
@@ -232,15 +232,11 @@
// Free reader so we own the descriptor position again.
reader = nullptr;
- // Remove excess data
- if (!Truncate(next_op_pos_)) {
- return false;
- }
if (lseek(fd_.get(), next_op_pos_, SEEK_SET) < 0) {
PLOG(ERROR) << "lseek failed";
return false;
}
- return true;
+ return EmitClusterIfNeeded();
}
bool CowWriter::EmitCopy(uint64_t new_block, uint64_t old_block) {
@@ -319,6 +315,14 @@
return WriteOperation(op);
}
+bool CowWriter::EmitClusterIfNeeded() {
+ // If there isn't room for another op and the cluster end op, end the current cluster
+ if (cluster_size_ && cluster_size_ < current_cluster_size_ + 2 * sizeof(CowOperation)) {
+ if (!EmitCluster()) return false;
+ }
+ return true;
+}
+
std::basic_string<uint8_t> CowWriter::Compress(const void* data, size_t length) {
switch (compression_) {
case kCowCompressGz: {
@@ -379,6 +383,21 @@
auto continue_num_ops = footer_.op.num_ops;
bool extra_cluster = false;
+ // Blank out extra ops, in case we're in append mode and dropped ops.
+ if (cluster_size_) {
+ auto unused_cluster_space = cluster_size_ - current_cluster_size_;
+ std::string clr;
+ clr.resize(unused_cluster_space, '\0');
+ if (lseek(fd_.get(), next_op_pos_, SEEK_SET) < 0) {
+ PLOG(ERROR) << "Failed to seek to footer position.";
+ return false;
+ }
+ if (!android::base::WriteFully(fd_, clr.data(), clr.size())) {
+ PLOG(ERROR) << "clearing unused cluster area failed";
+ return false;
+ }
+ }
+
// Footer should be at the end of a file, so if there is data after the current block, end it
// and start a new cluster.
if (cluster_size_ && current_data_size_ > 0) {
@@ -403,6 +422,17 @@
return false;
}
+ // Remove excess data, if we're in append mode and threw away more data
+ // than we wrote before.
+ off_t offs = lseek(fd_.get(), 0, SEEK_CUR);
+ if (offs < 0) {
+ PLOG(ERROR) << "Failed to lseek to find current position";
+ return false;
+ }
+ if (!Truncate(offs)) {
+ return false;
+ }
+
// Reposition for additional Writing
if (extra_cluster) {
current_cluster_size_ = continue_cluster_size;
@@ -445,12 +475,7 @@
if (!WriteRawData(data, size)) return false;
}
AddOperation(op);
- // If there isn't room for another op and the cluster end op, end the current cluster
- if (cluster_size_ && op.type != kCowClusterOp &&
- cluster_size_ < current_cluster_size_ + 2 * sizeof(op)) {
- if (!EmitCluster()) return false;
- }
- return true;
+ return EmitClusterIfNeeded();
}
void CowWriter::AddOperation(const CowOperation& op) {
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
index 6ffd5d8..a9efad8 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
@@ -115,6 +115,7 @@
private:
bool EmitCluster();
+ bool EmitClusterIfNeeded();
void SetupHeaders();
bool ParseOptions();
bool OpenForWrite();