Merge "libsnapshot: Implement CowWriterV3::EmitzeroBlocks." into main
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
index 4cbcab1..755a3af 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
@@ -145,6 +145,7 @@
size_t ignore_bytes = 0) override;
CowHeader& GetHeader() override { return header_; }
+ const CowHeaderV3& header_v3() const { return header_; }
bool GetRawBytes(const CowOperation* op, void* buffer, size_t len, size_t* read);
bool GetRawBytes(uint64_t offset, void* buffer, size_t len, size_t* read);
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
index 3016e93..5b1e56c 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
@@ -54,6 +54,9 @@
// Batch write cluster ops
bool batch_write = false;
+
+ // Size of the cow operation buffer; used in v3 only.
+ uint32_t op_count_max = 0;
};
// Interface for writing to a snapuserd COW. All operations are ordered; merges
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
index a07ced5..07c1d4f 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
@@ -89,5 +89,36 @@
ASSERT_EQ(header.cluster_ops, 0);
}
+TEST_F(CowTestV3, ZeroOp) {
+ CowOptions options;
+ options.op_count_max = 20;
+ auto writer = CreateCowWriter(3, options, GetCowFd());
+ ASSERT_TRUE(writer->AddZeroBlocks(1, 2));
+ ASSERT_TRUE(writer->Finalize());
+
+ CowReader reader;
+ ASSERT_TRUE(reader.Parse(cow_->fd));
+ ASSERT_EQ(reader.header_v3().op_count, 2);
+
+ auto iter = reader.GetOpIter();
+ ASSERT_NE(iter, nullptr);
+ ASSERT_FALSE(iter->AtEnd());
+
+ auto op = iter->Get();
+ ASSERT_EQ(op->type, kCowZeroOp);
+ ASSERT_EQ(op->data_length, 0);
+ ASSERT_EQ(op->new_block, 1);
+ ASSERT_EQ(op->source_info, 0);
+
+ iter->Next();
+ ASSERT_FALSE(iter->AtEnd());
+ op = iter->Get();
+
+ ASSERT_EQ(op->type, kCowZeroOp);
+ ASSERT_EQ(op->data_length, 0);
+ ASSERT_EQ(op->new_block, 2);
+ ASSERT_EQ(op->source_info, 0);
+}
+
} // namespace snapshot
} // namespace android
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_base.h b/fs_mgr/libsnapshot/libsnapshot_cow/writer_base.h
index 709b248..5274456 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_base.h
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_base.h
@@ -62,6 +62,8 @@
bool InitFd();
bool ValidateNewBlock(uint64_t new_block);
+ bool IsEstimating() const { return is_dev_null_; }
+
CowOptions options_;
android::base::unique_fd fd_;
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
index d69254f..ecbf97e 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
@@ -155,6 +155,7 @@
return false;
}
}
+ header_.op_count_max = options_.op_count_max;
if (!Sync()) {
LOG(ERROR) << "Header sync failed";
@@ -184,9 +185,17 @@
}
bool CowWriterV3::EmitZeroBlocks(uint64_t new_block_start, uint64_t num_blocks) {
- LOG(ERROR) << __LINE__ << " " << __FILE__ << " <- function here should never be called";
- if (new_block_start && num_blocks) return false;
- return false;
+ for (uint64_t i = 0; i < num_blocks; i++) {
+ CowOperationV3 op;
+ op.type = kCowZeroOp;
+ op.data_length = 0;
+ op.new_block = new_block_start + i;
+ op.source_info = 0;
+ if (!WriteOperation(op)) {
+ return false;
+ }
+ }
+ return true;
}
bool CowWriterV3::EmitLabel(uint64_t label) {
@@ -201,7 +210,33 @@
return false;
}
+bool CowWriterV3::WriteOperation(const CowOperationV3& op) {
+ if (IsEstimating()) {
+ header_.op_count++;
+ header_.op_count_max++;
+ return true;
+ }
+
+ if (header_.op_count + 1 > header_.op_count_max) {
+ LOG(ERROR) << "Maximum number of ops reached: " << header_.op_count_max;
+ return false;
+ }
+
+ const off_t offset = GetOpOffset(header_.op_count);
+ if (!android::base::WriteFullyAtOffset(fd_, &op, sizeof(op), offset)) {
+ return false;
+ }
+
+ header_.op_count++;
+ return true;
+}
+
bool CowWriterV3::Finalize() {
+ CHECK_GE(header_.prefix.header_size, sizeof(CowHeaderV3));
+ CHECK_LE(header_.prefix.header_size, sizeof(header_));
+ if (!android::base::WriteFullyAtOffset(fd_, &header_, header_.prefix.header_size, 0)) {
+ return false;
+ }
return Sync();
}
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
index a0d7ab9..8717c01 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
@@ -14,7 +14,8 @@
#pragma once
-#include <future>
+#include <android-base/logging.h>
+
#include "writer_base.h"
namespace android {
@@ -42,6 +43,13 @@
void SetupHeaders();
bool ParseOptions();
bool OpenForWrite();
+ bool WriteOperation(const CowOperationV3& op);
+
+ off_t GetOpOffset(uint32_t op_index) const {
+ CHECK_LT(op_index, header_.op_count_max);
+ return header_.prefix.header_size + header_.buffer_size +
+ (op_index * sizeof(CowOperationV3));
+ }
private:
CowHeaderV3 header_{};