diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
index 5b1e56c..ca0ebe1 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
@@ -33,7 +33,10 @@
 
 namespace android {
 namespace snapshot {
-
+struct CowSizeInfo {
+    uint64_t cow_size;
+    uint64_t op_count_max;
+};
 struct CowOptions {
     uint32_t block_size = 4096;
     std::string compression;
@@ -92,8 +95,9 @@
     // to ensure that the correct headers and footers are written.
     virtual bool Finalize() = 0;
 
-    // Return number of bytes the cow image occupies on disk.
-    virtual uint64_t GetCowSize() = 0;
+    // Return number of bytes the cow image occupies on disk + the size of sequence && ops buffer
+    // The latter two fields are used in v3 cow format and left as 0 for v2 cow format
+    virtual CowSizeInfo GetCowSizeInfo() const = 0;
 
     virtual uint32_t GetBlockSize() const = 0;
     virtual std::optional<uint32_t> GetMaxBlocks() const = 0;
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/mock_cow_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/mock_cow_writer.h
index c58c654..8491fb0 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/mock_cow_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/mock_cow_writer.h
@@ -24,8 +24,7 @@
     using FileDescriptor = chromeos_update_engine::FileDescriptor;
 
     MOCK_METHOD(bool, Finalize, (), (override));
-
-    MOCK_METHOD(uint64_t, GetCowSize, (), (override));
+    MOCK_METHOD(CowSizeInfo, GetCowSizeInfo, (), (const, override));
 
     MOCK_METHOD(bool, AddCopy, (uint64_t, uint64_t, uint64_t), (override));
     MOCK_METHOD(bool, AddRawBlocks, (uint64_t, const void*, size_t), (override));
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp
index 49d86d8..1d1d24c 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp
@@ -601,14 +601,14 @@
     ASSERT_TRUE(writer.AddCopy(10, 20));
     ASSERT_TRUE(writer.AddRawBlocks(50, data.data(), data.size()));
     ASSERT_TRUE(writer.AddZeroBlocks(51, 2));
-    auto size_before = writer.GetCowSize();
+    auto size_before = writer.GetCowSizeInfo().cow_size;
     ASSERT_TRUE(writer.Finalize());
-    auto size_after = writer.GetCowSize();
+    auto size_after = writer.GetCowSizeInfo().cow_size;
     ASSERT_EQ(size_before, size_after);
     struct stat buf;
 
     ASSERT_GE(fstat(cow_->fd, &buf), 0) << strerror(errno);
-    ASSERT_EQ(buf.st_size, writer.GetCowSize());
+    ASSERT_EQ(buf.st_size, writer.GetCowSizeInfo().cow_size);
 }
 
 TEST_F(CowTest, AppendLabelSmall) {
@@ -637,7 +637,7 @@
 
     struct stat buf;
     ASSERT_EQ(fstat(cow_->fd, &buf), 0);
-    ASSERT_EQ(buf.st_size, writer->GetCowSize());
+    ASSERT_EQ(buf.st_size, writer->GetCowSizeInfo().cow_size);
 
     // Read back both operations, and label.
     CowReader reader;
@@ -690,7 +690,7 @@
     ASSERT_TRUE(writer->AddRawBlocks(50, data.data(), data.size()));
     ASSERT_TRUE(writer->AddLabel(1));
     // Drop the tail end of the last op header, corrupting it.
-    ftruncate(cow_->fd, writer->GetCowSize() - sizeof(CowFooter) - 3);
+    ftruncate(cow_->fd, writer->GetCowSizeInfo().cow_size - sizeof(CowFooter) - 3);
 
     ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
 
@@ -705,7 +705,7 @@
 
     struct stat buf;
     ASSERT_EQ(fstat(cow_->fd, &buf), 0);
-    ASSERT_EQ(buf.st_size, writer->GetCowSize());
+    ASSERT_EQ(buf.st_size, writer->GetCowSizeInfo().cow_size);
 
     // Read back both operations.
     CowReader reader;
@@ -763,7 +763,7 @@
 
     struct stat buf;
     ASSERT_EQ(fstat(cow_->fd, &buf), 0);
-    ASSERT_EQ(buf.st_size, writer->GetCowSize());
+    ASSERT_EQ(buf.st_size, writer->GetCowSizeInfo().cow_size);
 
     // Read back all valid operations
     CowReader reader;
@@ -812,7 +812,7 @@
 
     struct stat buf;
     ASSERT_EQ(fstat(cow_->fd, &buf), 0);
-    ASSERT_EQ(buf.st_size, writer->GetCowSize());
+    ASSERT_EQ(buf.st_size, writer->GetCowSizeInfo().cow_size);
 
     // Read back all ops
     CowReader reader;
@@ -989,7 +989,7 @@
 
     struct stat buf;
     ASSERT_EQ(fstat(cow_->fd, &buf), 0);
-    ASSERT_EQ(buf.st_size, writer->GetCowSize());
+    ASSERT_EQ(buf.st_size, writer->GetCowSizeInfo().cow_size);
 
     // Read back both operations, plus cluster op at end
     CowReader reader;
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
index 3383a58..8cf46f4 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
@@ -658,14 +658,14 @@
     options.compression = "none";
     auto estimator = android::snapshot::CreateCowEstimator(3, options);
     ASSERT_TRUE(estimator->AddZeroBlocks(0, 1024 * 1024));
-    const auto cow_size = estimator->GetCowSize();
+    const auto cow_size = estimator->GetCowSizeInfo().cow_size;
     options.op_count_max = 1024 * 1024;
     options.max_blocks = 1024 * 1024;
     CowWriterV3 writer(options, GetCowFd());
     ASSERT_TRUE(writer.Initialize());
     ASSERT_TRUE(writer.AddZeroBlocks(0, 1024 * 1024));
 
-    ASSERT_LE(writer.GetCowSize(), cow_size);
+    ASSERT_LE(writer.GetCowSizeInfo().cow_size, cow_size);
 }
 
 TEST_F(CowTestV3, CopyOpMany) {
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp
index f9a4e47..75cd111 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp
@@ -576,12 +576,14 @@
     return Sync();
 }
 
-uint64_t CowWriterV2::GetCowSize() {
+CowSizeInfo CowWriterV2::GetCowSizeInfo() const {
+    CowSizeInfo info;
     if (current_data_size_ > 0) {
-        return next_data_pos_ + sizeof(footer_);
+        info.cow_size = next_data_pos_ + sizeof(footer_);
     } else {
-        return next_op_pos_ + sizeof(footer_);
+        info.cow_size = next_op_pos_ + sizeof(footer_);
     }
+    return info;
 }
 
 bool CowWriterV2::GetDataPos(uint64_t* pos) {
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h
index 50e635f..05de2ad 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h
@@ -27,7 +27,7 @@
 
     bool Initialize(std::optional<uint64_t> label = {}) override;
     bool Finalize() override;
-    uint64_t GetCowSize() override;
+    CowSizeInfo GetCowSizeInfo() const override;
 
   protected:
     virtual bool EmitCopy(uint64_t new_block, uint64_t old_block, uint64_t num_blocks = 1) override;
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
index d99e6e6..824fa39 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
@@ -491,8 +491,11 @@
     return Sync();
 }
 
-uint64_t CowWriterV3::GetCowSize() {
-    return next_data_pos_;
+CowSizeInfo CowWriterV3::GetCowSizeInfo() const {
+    CowSizeInfo info;
+    info.cow_size = next_data_pos_;
+    info.op_count_max = header_.op_count_max;
+    return info;
 }
 
 }  // namespace snapshot
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
index 3a7b877..73ac520 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
@@ -30,7 +30,7 @@
 
     bool Initialize(std::optional<uint64_t> label = {}) override;
     bool Finalize() override;
-    uint64_t GetCowSize() override;
+    CowSizeInfo GetCowSizeInfo() const override;
 
   protected:
     virtual bool EmitCopy(uint64_t new_block, uint64_t old_block, uint64_t num_blocks = 1) override;