libsnapshot: Clone worker readers from snapuserd
We'll need to have the Cow Files parsed to deal with xor ops, since
their data location is implicit from the format. Since the relevant data
is all stored in shared pointers, we can pass that data into the workers
without needing to reparse or copy.
Bug: 177104308
Test: builds
Change-Id: I96ac3da1ae620be48e5340c9f146c523b3ce74b6
diff --git a/fs_mgr/libsnapshot/cow_reader.cpp b/fs_mgr/libsnapshot/cow_reader.cpp
index 2acd158..3f59001 100644
--- a/fs_mgr/libsnapshot/cow_reader.cpp
+++ b/fs_mgr/libsnapshot/cow_reader.cpp
@@ -45,6 +45,23 @@
#endif
}
+std::unique_ptr<CowReader> CowReader::CloneCowReader() {
+ auto cow = std::make_unique<CowReader>();
+ cow->owned_fd_.reset();
+ cow->header_ = header_;
+ cow->footer_ = footer_;
+ cow->fd_size_ = fd_size_;
+ cow->last_label_ = last_label_;
+ cow->ops_ = ops_;
+ cow->merge_op_blocks_ = merge_op_blocks_;
+ cow->block_map_ = block_map_;
+ cow->num_total_data_ops_ = num_total_data_ops_;
+ cow->num_ordered_ops_to_merge_ = num_ordered_ops_to_merge_;
+ cow->has_seq_ops_ = has_seq_ops_;
+ cow->data_loc_ = data_loc_;
+ return cow;
+}
+
bool CowReader::InitForMerge(android::base::unique_fd&& fd) {
owned_fd_ = std::move(fd);
fd_ = owned_fd_.get();
@@ -138,6 +155,7 @@
bool CowReader::ParseOps(std::optional<uint64_t> label) {
uint64_t pos;
+ auto data_loc = std::make_shared<std::unordered_map<uint64_t, uint64_t>>();
// Skip the scratch space
if (header_.major_version >= 2 && (header_.buffer_size > 0)) {
@@ -185,7 +203,7 @@
auto& current_op = ops_buffer->data()[current_op_num];
current_op_num++;
if (current_op.type == kCowXorOp) {
- data_loc_[current_op.new_block] = data_pos;
+ data_loc->insert({current_op.new_block, data_pos});
}
pos += sizeof(CowOperation) + GetNextOpOffset(current_op, header_.cluster_ops);
data_pos += current_op.data_length + GetNextDataOffset(current_op, header_.cluster_ops);
@@ -279,6 +297,7 @@
ops_ = ops_buffer;
ops_->shrink_to_fit();
+ data_loc_ = data_loc;
return true;
}
@@ -619,7 +638,7 @@
uint64_t offset;
if (op.type == kCowXorOp) {
- offset = data_loc_[op.new_block];
+ offset = data_loc_->at(op.new_block);
} else {
offset = op.source;
}
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
index eeaa5c6..0786e82 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
@@ -136,6 +136,9 @@
void CloseCowFd() { owned_fd_ = {}; }
+ // Creates a clone of the current CowReader without the file handlers
+ std::unique_ptr<CowReader> CloneCowReader();
+
private:
bool ParseOps(std::optional<uint64_t> label);
bool PrepMergeOps();
@@ -153,7 +156,7 @@
uint64_t num_total_data_ops_;
uint64_t num_ordered_ops_to_merge_;
bool has_seq_ops_;
- std::unordered_map<uint64_t, uint64_t> data_loc_;
+ std::shared_ptr<std::unordered_map<uint64_t, uint64_t>> data_loc_;
};
} // namespace snapshot
diff --git a/fs_mgr/libsnapshot/snapuserd/snapuserd.cpp b/fs_mgr/libsnapshot/snapuserd/snapuserd.cpp
index 31d0221..e0675b4 100644
--- a/fs_mgr/libsnapshot/snapuserd/snapuserd.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/snapuserd.cpp
@@ -53,6 +53,10 @@
return true;
}
+std::unique_ptr<CowReader> Snapuserd::CloneReaderForWorker() {
+ return reader_->CloneCowReader();
+}
+
bool Snapuserd::CommitMerge(int num_merge_ops) {
struct CowHeader* ch = reinterpret_cast<struct CowHeader*>(mapped_addr_);
ch->num_merge_ops += num_merge_ops;
diff --git a/fs_mgr/libsnapshot/snapuserd/snapuserd.h b/fs_mgr/libsnapshot/snapuserd/snapuserd.h
index 95d2f77..3cb5ee2 100644
--- a/fs_mgr/libsnapshot/snapuserd/snapuserd.h
+++ b/fs_mgr/libsnapshot/snapuserd/snapuserd.h
@@ -244,6 +244,7 @@
void* GetExceptionBuffer(size_t i) { return vec_[i].get(); }
bool InitializeWorkers();
+ std::unique_ptr<CowReader> CloneReaderForWorker();
std::shared_ptr<Snapuserd> GetSharedPtr() { return shared_from_this(); }
std::vector<std::pair<sector_t, const CowOperation*>>& GetChunkVec() { return chunk_vec_; }
diff --git a/fs_mgr/libsnapshot/snapuserd/snapuserd_worker.cpp b/fs_mgr/libsnapshot/snapuserd/snapuserd_worker.cpp
index 13d45fe..d515f64 100644
--- a/fs_mgr/libsnapshot/snapuserd/snapuserd_worker.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/snapuserd_worker.cpp
@@ -105,11 +105,11 @@
}
bool WorkerThread::InitReader() {
- reader_ = std::make_unique<CowReader>();
+ reader_ = snapuserd_->CloneReaderForWorker();
+
if (!reader_->InitForMerge(std::move(cow_fd_))) {
return false;
}
-
return true;
}