diff --git a/fs_mgr/libsnapshot/cow_api_test.cpp b/fs_mgr/libsnapshot/cow_api_test.cpp
index b75b154..7f7e40a 100644
--- a/fs_mgr/libsnapshot/cow_api_test.cpp
+++ b/fs_mgr/libsnapshot/cow_api_test.cpp
@@ -981,6 +981,137 @@
     ASSERT_EQ(num_clusters, 1);
 }
 
+TEST_F(CowTest, BigSeqOp) {
+    CowOptions options;
+    CowWriter writer(options);
+    const int seq_len = std::numeric_limits<uint16_t>::max() / sizeof(uint32_t) + 1;
+    uint32_t sequence[seq_len];
+    for (int i = 0; i < seq_len; i++) {
+        sequence[i] = i + 1;
+    }
+
+    ASSERT_TRUE(writer.Initialize(cow_->fd));
+
+    ASSERT_TRUE(writer.AddSequenceData(seq_len, sequence));
+    ASSERT_TRUE(writer.AddZeroBlocks(1, seq_len));
+    ASSERT_TRUE(writer.Finalize());
+
+    ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+    CowReader reader;
+    ASSERT_TRUE(reader.Parse(cow_->fd));
+    auto iter = reader.GetRevMergeOpIter();
+
+    for (int i = 0; i < seq_len; i++) {
+        ASSERT_TRUE(!iter->Done());
+        const auto& op = iter->Get();
+
+        ASSERT_EQ(op.new_block, seq_len - i);
+
+        iter->Next();
+    }
+    ASSERT_TRUE(iter->Done());
+}
+
+TEST_F(CowTest, RevMergeOpItrTest) {
+    CowOptions options;
+    options.cluster_ops = 5;
+    options.num_merge_ops = 1;
+    CowWriter writer(options);
+    uint32_t sequence[] = {2, 10, 6, 7, 3, 5};
+
+    ASSERT_TRUE(writer.Initialize(cow_->fd));
+
+    ASSERT_TRUE(writer.AddSequenceData(6, sequence));
+    ASSERT_TRUE(writer.AddCopy(6, 3));
+    ASSERT_TRUE(writer.AddZeroBlocks(12, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(8, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(11, 1));
+    ASSERT_TRUE(writer.AddCopy(3, 5));
+    ASSERT_TRUE(writer.AddCopy(2, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(4, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(9, 1));
+    ASSERT_TRUE(writer.AddCopy(5, 6));
+    ASSERT_TRUE(writer.AddZeroBlocks(1, 1));
+    ASSERT_TRUE(writer.AddCopy(10, 2));
+    ASSERT_TRUE(writer.AddCopy(7, 4));
+    ASSERT_TRUE(writer.Finalize());
+
+    // New block in cow order is 6, 12, 8, 11, 3, 2, 4, 9, 5, 1, 10, 7
+    // New block in merge order is 2, 10, 6, 7, 3, 5, 12, 11, 9, 8, 4, 1
+    // RevMergeOrder is 1, 4, 8, 9, 11, 12, 5, 3, 7, 6, 10, 2
+    // new block 2 is "already merged", so will be left out.
+
+    std::vector<uint64_t> revMergeOpSequence = {1, 4, 8, 9, 11, 12, 5, 3, 7, 6, 10};
+
+    ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+    CowReader reader;
+    ASSERT_TRUE(reader.Parse(cow_->fd));
+    auto iter = reader.GetRevMergeOpIter();
+    auto expected_new_block = revMergeOpSequence.begin();
+
+    while (!iter->Done() && expected_new_block != revMergeOpSequence.end()) {
+        const auto& op = iter->Get();
+
+        ASSERT_EQ(op.new_block, *expected_new_block);
+
+        iter->Next();
+        expected_new_block++;
+    }
+    ASSERT_EQ(expected_new_block, revMergeOpSequence.end());
+    ASSERT_TRUE(iter->Done());
+}
+
+TEST_F(CowTest, LegacyRevMergeOpItrTest) {
+    CowOptions options;
+    options.cluster_ops = 5;
+    options.num_merge_ops = 1;
+    CowWriter writer(options);
+
+    ASSERT_TRUE(writer.Initialize(cow_->fd));
+
+    ASSERT_TRUE(writer.AddCopy(2, 1));
+    ASSERT_TRUE(writer.AddCopy(10, 2));
+    ASSERT_TRUE(writer.AddCopy(6, 3));
+    ASSERT_TRUE(writer.AddCopy(7, 4));
+    ASSERT_TRUE(writer.AddCopy(3, 5));
+    ASSERT_TRUE(writer.AddCopy(5, 6));
+    ASSERT_TRUE(writer.AddZeroBlocks(12, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(8, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(11, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(4, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(9, 1));
+    ASSERT_TRUE(writer.AddZeroBlocks(1, 1));
+
+    ASSERT_TRUE(writer.Finalize());
+
+    // New block in cow order is 2, 10, 6, 7, 3, 5, 12, 8, 11, 4, 9, 1
+    // New block in merge order is 2, 10, 6, 7, 3, 5, 12, 11, 9, 8, 4, 1
+    // RevMergeOrder is 1, 4, 8, 9, 11, 12, 5, 3, 7, 6, 10, 2
+    // new block 2 is "already merged", so will be left out.
+
+    std::vector<uint64_t> revMergeOpSequence = {1, 4, 8, 9, 11, 12, 5, 3, 7, 6, 10};
+
+    ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+    CowReader reader;
+    ASSERT_TRUE(reader.Parse(cow_->fd));
+    auto iter = reader.GetRevMergeOpIter();
+    auto expected_new_block = revMergeOpSequence.begin();
+
+    while (!iter->Done() && expected_new_block != revMergeOpSequence.end()) {
+        const auto& op = iter->Get();
+
+        ASSERT_EQ(op.new_block, *expected_new_block);
+
+        iter->Next();
+        expected_new_block++;
+    }
+    ASSERT_EQ(expected_new_block, revMergeOpSequence.end());
+    ASSERT_TRUE(iter->Done());
+}
+
 }  // namespace snapshot
 }  // namespace android
 
diff --git a/fs_mgr/libsnapshot/cow_format.cpp b/fs_mgr/libsnapshot/cow_format.cpp
index 0753c49..3085f80 100644
--- a/fs_mgr/libsnapshot/cow_format.cpp
+++ b/fs_mgr/libsnapshot/cow_format.cpp
@@ -37,6 +37,8 @@
         os << "kCowLabelOp,   ";
     else if (op.type == kCowClusterOp)
         os << "kCowClusterOp  ";
+    else if (op.type == kCowSequenceOp)
+        os << "kCowSequenceOp ";
     else if (op.type == kCowFooterOp)
         os << "kCowFooterOp  ";
     else
@@ -81,6 +83,16 @@
         case kCowLabelOp:
         case kCowClusterOp:
         case kCowFooterOp:
+        case kCowSequenceOp:
+            return true;
+        default:
+            return false;
+    }
+}
+
+bool IsOrderedOp(const CowOperation& op) {
+    switch (op.type) {
+        case kCowCopyOp:
             return true;
         default:
             return false;
diff --git a/fs_mgr/libsnapshot/cow_reader.cpp b/fs_mgr/libsnapshot/cow_reader.cpp
index 2349e4a..b3198a0 100644
--- a/fs_mgr/libsnapshot/cow_reader.cpp
+++ b/fs_mgr/libsnapshot/cow_reader.cpp
@@ -19,6 +19,9 @@
 
 #include <limits>
 #include <optional>
+#include <set>
+#include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
 #include <android-base/file.h>
@@ -127,7 +130,10 @@
         return false;
     }
 
-    return ParseOps(label);
+    if (!ParseOps(label)) {
+        return false;
+    }
+    return PrepMergeOps();
 }
 
 bool CowReader::ParseOps(std::optional<uint64_t> label) {
@@ -201,6 +207,8 @@
                 current_op_num--;
                 done = true;
                 break;
+            } else if (current_op.type == kCowSequenceOp) {
+                has_seq_ops_ = true;
             }
         }
 
@@ -251,7 +259,7 @@
             LOG(ERROR) << "ops checksum does not match";
             return false;
         }
-        SHA256(ops_buffer.get()->data(), footer_->op.ops_size, csum);
+        SHA256(ops_buffer->data(), footer_->op.ops_size, csum);
         if (memcmp(csum, footer_->data.ops_checksum, sizeof(csum)) != 0) {
             LOG(ERROR) << "ops checksum does not match";
             return false;
@@ -264,138 +272,165 @@
     return true;
 }
 
-void CowReader::InitializeMerge() {
-    uint64_t num_copy_ops = 0;
+//
+// This sets up the data needed for MergeOpIter. MergeOpIter presents
+// data in the order we intend to merge in.
+//
+// We merge all order sensitive ops up front, and sort the rest to allow for
+// batch merging. Order sensitive ops can either be presented in their proper
+// order in the cow, or be ordered by sequence ops (kCowSequenceOp), in which
+// case we want to merge those ops first, followed by any ops not specified by
+// new_block value by the sequence op, in sorted order.
+// We will re-arrange the vector in such a way that
+// kernel can batch merge. Ex:
+//
+// Existing COW format; All the copy operations
+// are at the beginning.
+// =======================================
+// Copy-op-1    - cow_op->new_block = 1
+// Copy-op-2    - cow_op->new_block = 2
+// Copy-op-3    - cow_op->new_block = 3
+// Replace-op-4 - cow_op->new_block = 6
+// Replace-op-5 - cow_op->new_block = 4
+// Replace-op-6 - cow_op->new_block = 8
+// Replace-op-7 - cow_op->new_block = 9
+// Zero-op-8    - cow_op->new_block = 7
+// Zero-op-9    - cow_op->new_block = 5
+// =======================================
+//
+// First find the operation which isn't a copy-op
+// and then sort all the operations in descending order
+// with the key being cow_op->new_block (source block)
+//
+// The data-structure will look like:
+//
+// =======================================
+// Copy-op-1    - cow_op->new_block = 1
+// Copy-op-2    - cow_op->new_block = 2
+// Copy-op-3    - cow_op->new_block = 3
+// Replace-op-7 - cow_op->new_block = 9
+// Replace-op-6 - cow_op->new_block = 8
+// Zero-op-8    - cow_op->new_block = 7
+// Replace-op-4 - cow_op->new_block = 6
+// Zero-op-9    - cow_op->new_block = 5
+// Replace-op-5 - cow_op->new_block = 4
+// =======================================
+//
+// Daemon will read the above data-structure in reverse-order
+// when reading metadata. Thus, kernel will get the metadata
+// in the following order:
+//
+// ========================================
+// Replace-op-5 - cow_op->new_block = 4
+// Zero-op-9    - cow_op->new_block = 5
+// Replace-op-4 - cow_op->new_block = 6
+// Zero-op-8    - cow_op->new_block = 7
+// Replace-op-6 - cow_op->new_block = 8
+// Replace-op-7 - cow_op->new_block = 9
+// Copy-op-3    - cow_op->new_block = 3
+// Copy-op-2    - cow_op->new_block = 2
+// Copy-op-1    - cow_op->new_block = 1
+// ===========================================
+//
+// When merging begins, kernel will start from the last
+// metadata which was read: In the above format, Copy-op-1
+// will be the first merge operation.
+//
+// Now, batching of the merge operations happens only when
+// 1: origin block numbers in the base device are contiguous
+// (cow_op->new_block) and,
+// 2: cow block numbers which are assigned by daemon in ReadMetadata()
+// are contiguous. These are monotonically increasing numbers.
+//
+// When both (1) and (2) are true, kernel will batch merge the operations.
+// In the above case, we have to ensure that the copy operations
+// are merged first before replace operations are done. Hence,
+// we will not change the order of copy operations. Since,
+// cow_op->new_block numbers are contiguous, we will ensure that the
+// cow block numbers assigned in ReadMetadata() for these respective copy
+// operations are not contiguous forcing kernel to issue merge for each
+// copy operations without batch merging.
+//
+// For all the other operations viz. Replace and Zero op, the cow block
+// numbers assigned by daemon will be contiguous allowing kernel to batch
+// merge.
+//
+// The final format after assiging COW block numbers by the daemon will
+// look something like:
+//
+// =========================================================
+// Replace-op-5 - cow_op->new_block = 4  cow-block-num = 2
+// Zero-op-9    - cow_op->new_block = 5  cow-block-num = 3
+// Replace-op-4 - cow_op->new_block = 6  cow-block-num = 4
+// Zero-op-8    - cow_op->new_block = 7  cow-block-num = 5
+// Replace-op-6 - cow_op->new_block = 8  cow-block-num = 6
+// Replace-op-7 - cow_op->new_block = 9  cow-block-num = 7
+// Copy-op-3    - cow_op->new_block = 3  cow-block-num = 9
+// Copy-op-2    - cow_op->new_block = 2  cow-block-num = 11
+// Copy-op-1    - cow_op->new_block = 1  cow-block-num = 13
+// ==========================================================
+//
+// Merge sequence will look like:
+//
+// Merge-1 - Batch-merge { Copy-op-1, Copy-op-2, Copy-op-3 }
+// Merge-2 - Batch-merge {Replace-op-7, Replace-op-6, Zero-op-8,
+//                        Replace-op-4, Zero-op-9, Replace-op-5 }
+//==============================================================
+bool CowReader::PrepMergeOps() {
+    auto merge_op_blocks = std::make_shared<std::vector<uint32_t>>();
+    std::set<int, std::greater<int>> other_ops;
+    auto seq_ops_set = std::unordered_set<uint32_t>();
+    auto block_map = std::make_shared<std::unordered_map<uint32_t, int>>();
+    int num_seqs = 0;
+    size_t read;
 
-    // Remove all the metadata operations
-    ops_->erase(std::remove_if(ops_.get()->begin(), ops_.get()->end(),
-                               [](CowOperation& op) { return IsMetadataOp(op); }),
-                ops_.get()->end());
-
-    set_total_data_ops(ops_->size());
-    // We will re-arrange the vector in such a way that
-    // kernel can batch merge. Ex:
-    //
-    // Existing COW format; All the copy operations
-    // are at the beginning.
-    // =======================================
-    // Copy-op-1    - cow_op->new_block = 1
-    // Copy-op-2    - cow_op->new_block = 2
-    // Copy-op-3    - cow_op->new_block = 3
-    // Replace-op-4 - cow_op->new_block = 6
-    // Replace-op-5 - cow_op->new_block = 4
-    // Replace-op-6 - cow_op->new_block = 8
-    // Replace-op-7 - cow_op->new_block = 9
-    // Zero-op-8    - cow_op->new_block = 7
-    // Zero-op-9    - cow_op->new_block = 5
-    // =======================================
-    //
-    // First find the operation which isn't a copy-op
-    // and then sort all the operations in descending order
-    // with the key being cow_op->new_block (source block)
-    //
-    // The data-structure will look like:
-    //
-    // =======================================
-    // Copy-op-1    - cow_op->new_block = 1
-    // Copy-op-2    - cow_op->new_block = 2
-    // Copy-op-3    - cow_op->new_block = 3
-    // Replace-op-7 - cow_op->new_block = 9
-    // Replace-op-6 - cow_op->new_block = 8
-    // Zero-op-8    - cow_op->new_block = 7
-    // Replace-op-4 - cow_op->new_block = 6
-    // Zero-op-9    - cow_op->new_block = 5
-    // Replace-op-5 - cow_op->new_block = 4
-    // =======================================
-    //
-    // Daemon will read the above data-structure in reverse-order
-    // when reading metadata. Thus, kernel will get the metadata
-    // in the following order:
-    //
-    // ========================================
-    // Replace-op-5 - cow_op->new_block = 4
-    // Zero-op-9    - cow_op->new_block = 5
-    // Replace-op-4 - cow_op->new_block = 6
-    // Zero-op-8    - cow_op->new_block = 7
-    // Replace-op-6 - cow_op->new_block = 8
-    // Replace-op-7 - cow_op->new_block = 9
-    // Copy-op-3    - cow_op->new_block = 3
-    // Copy-op-2    - cow_op->new_block = 2
-    // Copy-op-1    - cow_op->new_block = 1
-    // ===========================================
-    //
-    // When merging begins, kernel will start from the last
-    // metadata which was read: In the above format, Copy-op-1
-    // will be the first merge operation.
-    //
-    // Now, batching of the merge operations happens only when
-    // 1: origin block numbers in the base device are contiguous
-    // (cow_op->new_block) and,
-    // 2: cow block numbers which are assigned by daemon in ReadMetadata()
-    // are contiguous. These are monotonically increasing numbers.
-    //
-    // When both (1) and (2) are true, kernel will batch merge the operations.
-    // In the above case, we have to ensure that the copy operations
-    // are merged first before replace operations are done. Hence,
-    // we will not change the order of copy operations. Since,
-    // cow_op->new_block numbers are contiguous, we will ensure that the
-    // cow block numbers assigned in ReadMetadata() for these respective copy
-    // operations are not contiguous forcing kernel to issue merge for each
-    // copy operations without batch merging.
-    //
-    // For all the other operations viz. Replace and Zero op, the cow block
-    // numbers assigned by daemon will be contiguous allowing kernel to batch
-    // merge.
-    //
-    // The final format after assiging COW block numbers by the daemon will
-    // look something like:
-    //
-    // =========================================================
-    // Replace-op-5 - cow_op->new_block = 4  cow-block-num = 2
-    // Zero-op-9    - cow_op->new_block = 5  cow-block-num = 3
-    // Replace-op-4 - cow_op->new_block = 6  cow-block-num = 4
-    // Zero-op-8    - cow_op->new_block = 7  cow-block-num = 5
-    // Replace-op-6 - cow_op->new_block = 8  cow-block-num = 6
-    // Replace-op-7 - cow_op->new_block = 9  cow-block-num = 7
-    // Copy-op-3    - cow_op->new_block = 3  cow-block-num = 9
-    // Copy-op-2    - cow_op->new_block = 2  cow-block-num = 11
-    // Copy-op-1    - cow_op->new_block = 1  cow-block-num = 13
-    // ==========================================================
-    //
-    // Merge sequence will look like:
-    //
-    // Merge-1 - Batch-merge { Copy-op-1, Copy-op-2, Copy-op-3 }
-    // Merge-2 - Batch-merge {Replace-op-7, Replace-op-6, Zero-op-8,
-    //                        Replace-op-4, Zero-op-9, Replace-op-5 }
-    //==============================================================
-
-    num_copy_ops = FindNumCopyops();
-
-    std::sort(ops_.get()->begin() + num_copy_ops, ops_.get()->end(),
-              [](CowOperation& op1, CowOperation& op2) -> bool {
-                  return op1.new_block > op2.new_block;
-              });
-
-    if (header_.num_merge_ops > 0) {
-        ops_->erase(ops_.get()->begin(), ops_.get()->begin() + header_.num_merge_ops);
-    }
-
-    num_copy_ops = FindNumCopyops();
-    set_copy_ops(num_copy_ops);
-}
-
-uint64_t CowReader::FindNumCopyops() {
-    uint64_t num_copy_ops = 0;
-
-    for (uint64_t i = 0; i < ops_->size(); i++) {
+    for (int i = 0; i < ops_->size(); i++) {
         auto& current_op = ops_->data()[i];
-        if (current_op.type != kCowCopyOp) {
-            break;
+
+        if (current_op.type == kCowSequenceOp) {
+            size_t seq_len = current_op.data_length / sizeof(uint32_t);
+
+            merge_op_blocks->resize(merge_op_blocks->size() + seq_len);
+            if (!GetRawBytes(current_op.source, &merge_op_blocks->data()[num_seqs],
+                             current_op.data_length, &read)) {
+                PLOG(ERROR) << "Failed to read sequence op!";
+                return false;
+            }
+            for (int j = num_seqs; j < num_seqs + seq_len; j++) {
+                seq_ops_set.insert(merge_op_blocks->data()[j]);
+            }
+            num_seqs += seq_len;
         }
-        num_copy_ops += 1;
+
+        if (IsMetadataOp(current_op)) {
+            continue;
+        }
+
+        if (!has_seq_ops_ && IsOrderedOp(current_op)) {
+            merge_op_blocks->emplace_back(current_op.new_block);
+        } else if (seq_ops_set.count(current_op.new_block) == 0) {
+            other_ops.insert(current_op.new_block);
+        }
+        block_map->insert({current_op.new_block, i});
+    }
+    if (merge_op_blocks->size() > header_.num_merge_ops)
+        num_ordered_ops_to_merge_ = merge_op_blocks->size() - header_.num_merge_ops;
+    else
+        num_ordered_ops_to_merge_ = 0;
+    merge_op_blocks->reserve(merge_op_blocks->size() + other_ops.size());
+    for (auto block : other_ops) {
+        merge_op_blocks->emplace_back(block);
     }
 
-    return num_copy_ops;
+    num_total_data_ops_ = merge_op_blocks->size();
+    if (header_.num_merge_ops > 0) {
+        merge_op_blocks->erase(merge_op_blocks->begin(),
+                               merge_op_blocks->begin() + header_.num_merge_ops);
+    }
+
+    block_map_ = block_map;
+    merge_op_blocks_ = merge_op_blocks;
+    return true;
 }
 
 bool CowReader::GetHeader(CowHeader* header) {
@@ -430,11 +465,11 @@
 
 CowOpIter::CowOpIter(std::shared_ptr<std::vector<CowOperation>>& ops) {
     ops_ = ops;
-    op_iter_ = ops_.get()->begin();
+    op_iter_ = ops_->begin();
 }
 
 bool CowOpIter::Done() {
-    return op_iter_ == ops_.get()->end();
+    return op_iter_ == ops_->end();
 }
 
 void CowOpIter::Next() {
@@ -447,9 +482,11 @@
     return (*op_iter_);
 }
 
-class CowOpReverseIter final : public ICowOpReverseIter {
+class CowRevMergeOpIter final : public ICowOpIter {
   public:
-    explicit CowOpReverseIter(std::shared_ptr<std::vector<CowOperation>> ops);
+    explicit CowRevMergeOpIter(std::shared_ptr<std::vector<CowOperation>> ops,
+                               std::shared_ptr<std::vector<uint32_t>> merge_op_blocks,
+                               std::shared_ptr<std::unordered_map<uint32_t, int>> map);
 
     bool Done() override;
     const CowOperation& Get() override;
@@ -457,34 +494,41 @@
 
   private:
     std::shared_ptr<std::vector<CowOperation>> ops_;
-    std::vector<CowOperation>::reverse_iterator op_riter_;
+    std::shared_ptr<std::vector<uint32_t>> merge_op_blocks_;
+    std::shared_ptr<std::unordered_map<uint32_t, int>> map_;
+    std::vector<uint32_t>::reverse_iterator block_riter_;
 };
 
-CowOpReverseIter::CowOpReverseIter(std::shared_ptr<std::vector<CowOperation>> ops) {
+CowRevMergeOpIter::CowRevMergeOpIter(std::shared_ptr<std::vector<CowOperation>> ops,
+                                     std::shared_ptr<std::vector<uint32_t>> merge_op_blocks,
+                                     std::shared_ptr<std::unordered_map<uint32_t, int>> map) {
     ops_ = ops;
-    op_riter_ = ops_.get()->rbegin();
+    merge_op_blocks_ = merge_op_blocks;
+    map_ = map;
+
+    block_riter_ = merge_op_blocks->rbegin();
 }
 
-bool CowOpReverseIter::Done() {
-    return op_riter_ == ops_.get()->rend();
+bool CowRevMergeOpIter::Done() {
+    return block_riter_ == merge_op_blocks_->rend();
 }
 
-void CowOpReverseIter::Next() {
+void CowRevMergeOpIter::Next() {
     CHECK(!Done());
-    op_riter_++;
+    block_riter_++;
 }
 
-const CowOperation& CowOpReverseIter::Get() {
+const CowOperation& CowRevMergeOpIter::Get() {
     CHECK(!Done());
-    return (*op_riter_);
+    return ops_->data()[map_->at(*block_riter_)];
 }
 
 std::unique_ptr<ICowOpIter> CowReader::GetOpIter() {
     return std::make_unique<CowOpIter>(ops_);
 }
 
-std::unique_ptr<ICowOpReverseIter> CowReader::GetRevOpIter() {
-    return std::make_unique<CowOpReverseIter>(ops_);
+std::unique_ptr<ICowOpIter> CowReader::GetRevMergeOpIter() {
+    return std::make_unique<CowRevMergeOpIter>(ops_, merge_op_blocks_, block_map_);
 }
 
 bool CowReader::GetRawBytes(uint64_t offset, void* buffer, size_t len, size_t* read) {
diff --git a/fs_mgr/libsnapshot/cow_writer.cpp b/fs_mgr/libsnapshot/cow_writer.cpp
index 526fede..51505bf 100644
--- a/fs_mgr/libsnapshot/cow_writer.cpp
+++ b/fs_mgr/libsnapshot/cow_writer.cpp
@@ -76,9 +76,8 @@
     return EmitLabel(label);
 }
 
-bool ICowWriter::AddSequenceData(size_t /*num_ops*/, const uint32_t* /*data*/) {
-    LOG(ERROR) << "AddSequenceData not yet implemented";
-    return false;
+bool ICowWriter::AddSequenceData(size_t num_ops, const uint32_t* data) {
+    return EmitSequenceData(num_ops, data);
 }
 
 bool ICowWriter::ValidateNewBlock(uint64_t new_block) {
@@ -103,7 +102,7 @@
     header_.footer_size = sizeof(CowFooter);
     header_.op_size = sizeof(CowOperation);
     header_.block_size = options_.block_size;
-    header_.num_merge_ops = 0;
+    header_.num_merge_ops = options_.num_merge_ops;
     header_.cluster_ops = options_.cluster_ops;
     header_.buffer_size = 0;
     footer_ = {};
@@ -337,6 +336,26 @@
     return WriteOperation(op) && Sync();
 }
 
+bool CowWriter::EmitSequenceData(size_t num_ops, const uint32_t* data) {
+    CHECK(!merge_in_progress_);
+    size_t to_add = 0;
+    size_t max_ops = std::numeric_limits<uint16_t>::max() / sizeof(uint32_t);
+    while (num_ops > 0) {
+        CowOperation op = {};
+        op.type = kCowSequenceOp;
+        op.source = next_data_pos_;
+        to_add = std::min(num_ops, max_ops);
+        op.data_length = static_cast<uint16_t>(to_add * sizeof(uint32_t));
+        if (!WriteOperation(op, data, op.data_length)) {
+            PLOG(ERROR) << "AddSequenceData: write failed";
+            return false;
+        }
+        num_ops -= to_add;
+        data += to_add;
+    }
+    return true;
+}
+
 bool CowWriter::EmitCluster() {
     CowOperation op = {};
     op.type = kCowClusterOp;
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
index 000e5e1..464046b 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
@@ -148,6 +148,7 @@
 static constexpr uint8_t kCowZeroOp = 3;
 static constexpr uint8_t kCowLabelOp = 4;
 static constexpr uint8_t kCowClusterOp = 5;
+static constexpr uint8_t kCowSequenceOp = 7;
 static constexpr uint8_t kCowFooterOp = -1;
 
 static constexpr uint8_t kCowCompressNone = 0;
@@ -184,7 +185,10 @@
 int64_t GetNextOpOffset(const CowOperation& op, uint32_t cluster_size);
 int64_t GetNextDataOffset(const CowOperation& op, uint32_t cluster_size);
 
+// Ops that are internal to the Cow Format and not OTA data
 bool IsMetadataOp(const CowOperation& op);
+// Ops that have dependencies on old blocks, and must take care in their merge order
+bool IsOrderedOp(const CowOperation& op);
 
 }  // namespace snapshot
 }  // namespace android
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
index 669e58a..05f7066 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h
@@ -19,6 +19,7 @@
 #include <functional>
 #include <memory>
 #include <optional>
+#include <unordered_map>
 
 #include <android-base/unique_fd.h>
 #include <libsnapshot/cow_format.h>
@@ -27,7 +28,6 @@
 namespace snapshot {
 
 class ICowOpIter;
-class ICowOpReverseIter;
 
 // A ByteSink object handles requests for a buffer of a specific size. It
 // always owns the underlying buffer. It's designed to minimize potential
@@ -75,8 +75,8 @@
     // Return an iterator for retrieving CowOperation entries.
     virtual std::unique_ptr<ICowOpIter> GetOpIter() = 0;
 
-    // Return an reverse iterator for retrieving CowOperation entries.
-    virtual std::unique_ptr<ICowOpReverseIter> GetRevOpIter() = 0;
+    // Return an iterator for retrieving CowOperation entries in merge order
+    virtual std::unique_ptr<ICowOpIter> GetRevMergeOpIter() = 0;
 
     // Get decoded bytes from the data section, handling any decompression.
     // All retrieved data is passed to the sink.
@@ -98,21 +98,6 @@
     virtual void Next() = 0;
 };
 
-// Reverse Iterate over a sequence of COW operations.
-class ICowOpReverseIter {
-  public:
-    virtual ~ICowOpReverseIter() {}
-
-    // True if there are more items to read, false otherwise.
-    virtual bool Done() = 0;
-
-    // Read the current operation.
-    virtual const CowOperation& Get() = 0;
-
-    // Advance to the next item.
-    virtual void Next() = 0;
-};
-
 class CowReader : public ICowReader {
   public:
     CowReader();
@@ -135,25 +120,21 @@
     // whose lifetime depends on the CowOpIter object; the return
     // value of these will never be null.
     std::unique_ptr<ICowOpIter> GetOpIter() override;
-    std::unique_ptr<ICowOpReverseIter> GetRevOpIter() override;
+    std::unique_ptr<ICowOpIter> GetRevMergeOpIter() override;
 
     bool ReadData(const CowOperation& op, IByteSink* sink) override;
 
     bool GetRawBytes(uint64_t offset, void* buffer, size_t len, size_t* read);
 
-    void InitializeMerge();
+    uint64_t get_num_total_data_ops() { return num_total_data_ops_; }
 
-    // Number of copy, replace, and zero ops. Set if InitializeMerge is called.
-    void set_total_data_ops(uint64_t size) { total_data_ops_ = size; }
-    uint64_t total_data_ops() { return total_data_ops_; }
-    // Number of copy ops. Set if InitializeMerge is called.
-    void set_copy_ops(uint64_t size) { copy_ops_ = size; }
-    uint64_t total_copy_ops() { return copy_ops_; }
+    uint64_t get_num_ordered_ops_to_merge() { return num_ordered_ops_to_merge_; }
 
     void CloseCowFd() { owned_fd_ = {}; }
 
   private:
     bool ParseOps(std::optional<uint64_t> label);
+    bool PrepMergeOps();
     uint64_t FindNumCopyops();
 
     android::base::unique_fd owned_fd_;
@@ -163,8 +144,11 @@
     uint64_t fd_size_;
     std::optional<uint64_t> last_label_;
     std::shared_ptr<std::vector<CowOperation>> ops_;
-    uint64_t total_data_ops_;
-    uint64_t copy_ops_;
+    std::shared_ptr<std::vector<uint32_t>> merge_op_blocks_;
+    std::shared_ptr<std::unordered_map<uint32_t, int>> block_map_;
+    uint64_t num_total_data_ops_;
+    uint64_t num_ordered_ops_to_merge_;
+    bool has_seq_ops_;
 };
 
 }  // namespace snapshot
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
index fbe6461..4a807fb 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_writer.h
@@ -38,6 +38,9 @@
     uint32_t cluster_ops = 200;
 
     bool scratch_space = true;
+
+    // Preset the number of merged ops. Only useful for testing.
+    uint64_t num_merge_ops = 0;
 };
 
 // Interface for writing to a snapuserd COW. All operations are ordered; merges
@@ -85,6 +88,7 @@
     virtual bool EmitRawBlocks(uint64_t new_block_start, const void* data, size_t size) = 0;
     virtual bool EmitZeroBlocks(uint64_t new_block_start, uint64_t num_blocks) = 0;
     virtual bool EmitLabel(uint64_t label) = 0;
+    virtual bool EmitSequenceData(size_t num_ops, const uint32_t* data) = 0;
 
     bool ValidateNewBlock(uint64_t new_block);
 
@@ -120,6 +124,7 @@
     virtual bool EmitRawBlocks(uint64_t new_block_start, const void* data, size_t size) override;
     virtual bool EmitZeroBlocks(uint64_t new_block_start, uint64_t num_blocks) override;
     virtual bool EmitLabel(uint64_t label) override;
+    virtual bool EmitSequenceData(size_t num_ops, const uint32_t* data) override;
 
   private:
     bool EmitCluster();
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot_writer.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot_writer.h
index bf5ce8b..c00dafa 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot_writer.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot_writer.h
@@ -76,6 +76,7 @@
     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 EmitLabel(uint64_t label) override;
+    bool EmitSequenceData(size_t num_ops, const uint32_t* data) override;
 
   private:
     android::base::unique_fd cow_device_;
@@ -103,6 +104,7 @@
     bool EmitZeroBlocks(uint64_t new_block_start, uint64_t num_blocks) override;
     bool EmitCopy(uint64_t new_block, uint64_t old_block) override;
     bool EmitLabel(uint64_t label) override;
+    bool EmitSequenceData(size_t num_ops, const uint32_t* data) override;
 
   private:
     android::base::unique_fd snapshot_fd_;
diff --git a/fs_mgr/libsnapshot/inspect_cow.cpp b/fs_mgr/libsnapshot/inspect_cow.cpp
index 1dc61af..ed86c87 100644
--- a/fs_mgr/libsnapshot/inspect_cow.cpp
+++ b/fs_mgr/libsnapshot/inspect_cow.cpp
@@ -40,8 +40,18 @@
     LOG(ERROR) << "\t -s Run Silent";
     LOG(ERROR) << "\t -d Attempt to decompress";
     LOG(ERROR) << "\t -b Show data for failed decompress\n";
+    LOG(ERROR) << "\t -m Show ops in reverse merge order\n";
 }
 
+enum OpIter { Normal, RevMerge };
+
+struct Options {
+    bool silent;
+    bool decompress;
+    bool show_bad;
+    OpIter iter_type;
+};
+
 // Sink that always appends to the end of a string.
 class StringSink : public IByteSink {
   public:
@@ -78,7 +88,7 @@
     }
 }
 
-static bool Inspect(const std::string& path, bool silent, bool decompress, bool show_bad) {
+static bool Inspect(const std::string& path, Options opt) {
     android::base::unique_fd fd(open(path.c_str(), O_RDONLY));
     if (fd < 0) {
         PLOG(ERROR) << "open failed: " << path;
@@ -100,7 +110,7 @@
     bool has_footer = false;
     if (reader.GetFooter(&footer)) has_footer = true;
 
-    if (!silent) {
+    if (!opt.silent) {
         std::cout << "Major version: " << header.major_version << "\n";
         std::cout << "Minor version: " << header.minor_version << "\n";
         std::cout << "Header size: " << header.header_size << "\n";
@@ -116,19 +126,24 @@
         }
     }
 
-    auto iter = reader.GetOpIter();
+    std::unique_ptr<ICowOpIter> iter;
+    if (opt.iter_type == Normal) {
+        iter = reader.GetOpIter();
+    } else if (opt.iter_type == RevMerge) {
+        iter = reader.GetRevMergeOpIter();
+    }
     StringSink sink;
     bool success = true;
     while (!iter->Done()) {
         const CowOperation& op = iter->Get();
 
-        if (!silent) std::cout << op << "\n";
+        if (!opt.silent) std::cout << op << "\n";
 
-        if (decompress && op.type == kCowReplaceOp && op.compression != kCowCompressNone) {
+        if (opt.decompress && op.type == kCowReplaceOp && op.compression != kCowCompressNone) {
             if (!reader.ReadData(op, &sink)) {
                 std::cerr << "Failed to decompress for :" << op << "\n";
                 success = false;
-                if (show_bad) ShowBad(reader, op);
+                if (opt.show_bad) ShowBad(reader, op);
             }
             sink.Reset();
         }
@@ -144,19 +159,24 @@
 
 int main(int argc, char** argv) {
     int ch;
-    bool silent = false;
-    bool decompress = false;
-    bool show_bad = false;
-    while ((ch = getopt(argc, argv, "sdb")) != -1) {
+    struct android::snapshot::Options opt;
+    opt.silent = false;
+    opt.decompress = false;
+    opt.show_bad = false;
+    opt.iter_type = android::snapshot::Normal;
+    while ((ch = getopt(argc, argv, "sdbm")) != -1) {
         switch (ch) {
             case 's':
-                silent = true;
+                opt.silent = true;
                 break;
             case 'd':
-                decompress = true;
+                opt.decompress = true;
                 break;
             case 'b':
-                show_bad = true;
+                opt.show_bad = true;
+                break;
+            case 'm':
+                opt.iter_type = android::snapshot::RevMerge;
                 break;
             default:
                 android::snapshot::usage();
@@ -169,7 +189,7 @@
         return 1;
     }
 
-    if (!android::snapshot::Inspect(argv[optind], silent, decompress, show_bad)) {
+    if (!android::snapshot::Inspect(argv[optind], opt)) {
         return 1;
     }
     return 0;
diff --git a/fs_mgr/libsnapshot/snapshot_writer.cpp b/fs_mgr/libsnapshot/snapshot_writer.cpp
index 080f3b7..34b3e87 100644
--- a/fs_mgr/libsnapshot/snapshot_writer.cpp
+++ b/fs_mgr/libsnapshot/snapshot_writer.cpp
@@ -114,6 +114,10 @@
     return cow_->AddLabel(label);
 }
 
+bool CompressedSnapshotWriter::EmitSequenceData(size_t num_ops, const uint32_t* data) {
+    return cow_->AddSequenceData(num_ops, data);
+}
+
 bool CompressedSnapshotWriter::Initialize() {
     return cow_->Initialize(cow_device_);
 }
@@ -183,6 +187,11 @@
     return true;
 }
 
+bool OnlineKernelSnapshotWriter::EmitSequenceData(size_t, const uint32_t*) {
+    // Not Needed
+    return true;
+}
+
 std::unique_ptr<FileDescriptor> OnlineKernelSnapshotWriter::OpenReader() {
     unique_fd fd(dup(snapshot_fd_.get()));
     if (fd < 0) {
diff --git a/fs_mgr/libsnapshot/snapuserd.cpp b/fs_mgr/libsnapshot/snapuserd.cpp
index 03c2ef6..e578a76 100644
--- a/fs_mgr/libsnapshot/snapuserd.cpp
+++ b/fs_mgr/libsnapshot/snapuserd.cpp
@@ -266,14 +266,15 @@
 
 void Snapuserd::CheckMergeCompletionStatus() {
     if (!merge_initiated_) {
-        SNAP_LOG(INFO) << "Merge was not initiated. Total-data-ops: " << reader_->total_data_ops();
+        SNAP_LOG(INFO) << "Merge was not initiated. Total-data-ops: "
+                       << reader_->get_num_total_data_ops();
         return;
     }
 
     struct CowHeader* ch = reinterpret_cast<struct CowHeader*>(mapped_addr_);
 
     SNAP_LOG(INFO) << "Merge-status: Total-Merged-ops: " << ch->num_merge_ops
-                   << " Total-data-ops: " << reader_->total_data_ops();
+                   << " Total-data-ops: " << reader_->get_num_total_data_ops();
 }
 
 /*
@@ -352,7 +353,6 @@
         return false;
     }
 
-    reader_->InitializeMerge();
     SNAP_LOG(DEBUG) << "Merge-ops: " << header.num_merge_ops;
 
     if (!MmapMetadata()) {
@@ -361,7 +361,7 @@
     }
 
     // Initialize the iterator for reading metadata
-    cowop_riter_ = reader_->GetRevOpIter();
+    std::unique_ptr<ICowOpIter> cowop_rm_iter = reader_->GetRevMergeOpIter();
 
     exceptions_per_area_ = (CHUNK_SIZE << SECTOR_SHIFT) / sizeof(struct disk_exception);
 
@@ -379,23 +379,18 @@
     // this memset will ensure that metadata read is completed.
     memset(de_ptr.get(), 0, (exceptions_per_area_ * sizeof(struct disk_exception)));
 
-    while (!cowop_riter_->Done()) {
-        const CowOperation* cow_op = &cowop_riter_->Get();
+    while (!cowop_rm_iter->Done()) {
+        const CowOperation* cow_op = &cowop_rm_iter->Get();
         struct disk_exception* de =
                 reinterpret_cast<struct disk_exception*>((char*)de_ptr.get() + offset);
 
-        if (IsMetadataOp(*cow_op)) {
-            cowop_riter_->Next();
-            continue;
-        }
-
         metadata_found = true;
         // This loop will handle all the replace and zero ops.
         // We will handle the copy ops later as it requires special
         // handling of assigning chunk-id's. Furthermore, we make
         // sure that replace/zero and copy ops are not batch merged; hence,
         // the bump in the chunk_id before break of this loop
-        if (cow_op->type == kCowCopyOp) {
+        if (IsOrderedOp(*cow_op)) {
             data_chunk_id = GetNextAllocatableChunkId(data_chunk_id);
             break;
         }
@@ -415,7 +410,7 @@
         chunk_vec_.push_back(std::make_pair(ChunkToSector(data_chunk_id), cow_op));
         num_ops += 1;
         offset += sizeof(struct disk_exception);
-        cowop_riter_->Next();
+        cowop_rm_iter->Next();
 
         SNAP_LOG(DEBUG) << num_ops << ":"
                         << " Old-chunk: " << de->old_chunk << " New-chunk: " << de->new_chunk;
@@ -432,7 +427,7 @@
                                                  sizeof(struct disk_exception));
             memset(de_ptr.get(), 0, (exceptions_per_area_ * sizeof(struct disk_exception)));
 
-            if (cowop_riter_->Done()) {
+            if (cowop_rm_iter->Done()) {
                 vec_.push_back(std::move(de_ptr));
             }
         }
@@ -445,18 +440,15 @@
     std::map<uint64_t, const CowOperation*> map;
     std::set<uint64_t> dest_blocks;
     size_t pending_copy_ops = exceptions_per_area_ - num_ops;
-    uint64_t total_copy_ops = reader_->total_copy_ops();
+    uint64_t total_copy_ops = reader_->get_num_ordered_ops_to_merge();
 
     SNAP_LOG(DEBUG) << " Processing copy-ops at Area: " << vec_.size()
                     << " Number of replace/zero ops completed in this area: " << num_ops
                     << " Pending copy ops for this area: " << pending_copy_ops;
-    while (!cowop_riter_->Done()) {
+
+    while (!cowop_rm_iter->Done()) {
         do {
-            const CowOperation* cow_op = &cowop_riter_->Get();
-            if (IsMetadataOp(*cow_op)) {
-                cowop_riter_->Next();
-                continue;
-            }
+            const CowOperation* cow_op = &cowop_rm_iter->Get();
 
             // We have two cases specific cases:
             //
@@ -572,8 +564,8 @@
             map[cow_op->new_block] = cow_op;
             dest_blocks.insert(cow_op->source);
             prev_id = cow_op->new_block;
-            cowop_riter_->Next();
-        } while (!cowop_riter_->Done() && pending_copy_ops);
+            cowop_rm_iter->Next();
+        } while (!cowop_rm_iter->Done() && pending_copy_ops);
 
         data_chunk_id = GetNextAllocatableChunkId(data_chunk_id);
         SNAP_LOG(DEBUG) << "Batch Merge copy-ops of size: " << map.size()
@@ -611,7 +603,7 @@
                                                      sizeof(struct disk_exception));
                 memset(de_ptr.get(), 0, (exceptions_per_area_ * sizeof(struct disk_exception)));
 
-                if (cowop_riter_->Done()) {
+                if (cowop_rm_iter->Done()) {
                     vec_.push_back(std::move(de_ptr));
                     SNAP_LOG(DEBUG) << "ReadMetadata() completed; Number of Areas: " << vec_.size();
                 }
@@ -661,7 +653,7 @@
                    << " Replace-ops: " << replace_ops << " Zero-ops: " << zero_ops
                    << " Copy-ops: " << copy_ops << " Areas: " << vec_.size()
                    << " Num-ops-merged: " << header.num_merge_ops
-                   << " Total-data-ops: " << reader_->total_data_ops();
+                   << " Total-data-ops: " << reader_->get_num_total_data_ops();
 
     // Total number of sectors required for creating dm-user device
     num_sectors_ = ChunkToSector(data_chunk_id);
diff --git a/fs_mgr/libsnapshot/snapuserd.h b/fs_mgr/libsnapshot/snapuserd.h
index 212c78e..5d86e4f 100644
--- a/fs_mgr/libsnapshot/snapuserd.h
+++ b/fs_mgr/libsnapshot/snapuserd.h
@@ -306,8 +306,6 @@
     uint32_t exceptions_per_area_;
     uint64_t num_sectors_;
 
-    std::unique_ptr<ICowOpIter> cowop_iter_;
-    std::unique_ptr<ICowOpReverseIter> cowop_riter_;
     std::unique_ptr<CowReader> reader_;
 
     // Vector of disk exception which is a