From b57cbebbe53d787e319acbf3ce71050e4ddd58e2 Mon Sep 17 00:00:00 2001
From: Zhichao Cao <zhichao@fb.com>
Date: Mon, 21 Sep 2020 16:05:39 -0700
Subject: [PATCH 1/3] Add AppendWithVerify and PositionedAppendWithVerify to
 Env and FileSystem

---
 env/composite_env_wrapper.h   | 28 ++++++++++++++++++++++++++++
 include/rocksdb/env.h         | 32 ++++++++++++++++++++++++++++++++
 include/rocksdb/file_system.h | 28 ++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+)

diff --git a/env/composite_env_wrapper.h b/env/composite_env_wrapper.h
index f12657a04b2..013b6cb4da6 100644
--- a/env/composite_env_wrapper.h
+++ b/env/composite_env_wrapper.h
@@ -115,11 +115,26 @@ class CompositeWritableFileWrapper : public WritableFile {
     IODebugContext dbg;
     return target_->Append(data, io_opts, &dbg);
   }
+  Status AppendWithVerify(
+      const Slice& data,
+      const DataVerificationInfo& verification_info) override {
+    IOOptions io_opts;
+    IODebugContext dbg;
+    return target_->AppendWithVerify(data, io_opts, &dbg, verification_info);
+  }
   Status PositionedAppend(const Slice& data, uint64_t offset) override {
     IOOptions io_opts;
     IODebugContext dbg;
     return target_->PositionedAppend(data, offset, io_opts, &dbg);
   }
+  Status PositionedAppendWithVerify(
+      const Slice& data, uint64_t offset,
+      const DataVerificationInfo& verification_info) override {
+    IOOptions io_opts;
+    IODebugContext dbg;
+    return target_->PositionedAppendWithVerify(data, offset, io_opts, &dbg,
+                                               verification_info);
+  }
   Status Truncate(uint64_t size) override {
     IOOptions io_opts;
     IODebugContext dbg;
@@ -727,11 +742,24 @@ class LegacyWritableFileWrapper : public FSWritableFile {
                   IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->Append(data));
   }
+  IOStatus AppendWithVerify(
+      const Slice& data, const IOOptions& /*options*/, IODebugContext* /*dbg*/,
+      const DataVerificationInfo& verification_info) override {
+    return status_to_io_status(
+        target_->AppendWithVerify(data, verification_info));
+  }
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                             const IOOptions& /*options*/,
                             IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->PositionedAppend(data, offset));
   }
+  IOStatus PositionedAppendWithVerify(
+      const Slice& data, uint64_t offset, const IOOptions& /*options*/,
+      IODebugContext* /*dbg*/,
+      const DataVerificationInfo& verification_info) override {
+    return status_to_io_status(
+        target_->PositionedAppendWithVerify(data, offset, verification_info));
+  }
   IOStatus Truncate(uint64_t size, const IOOptions& /*options*/,
                     IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->Truncate(size));
diff --git a/include/rocksdb/env.h b/include/rocksdb/env.h
index 955d591c310..78fe7fc860c 100644
--- a/include/rocksdb/env.h
+++ b/include/rocksdb/env.h
@@ -740,6 +740,14 @@ class RandomAccessFile {
   // RandomAccessFileWrapper too.
 };
 
+// A data structure brings the data verification information, which is
+// used togther with data being written to a file.
+struct DataVerificationInfo {
+  DataVerificationInfo(const std::string& checksum_) : checksum(checksum_) {}
+  // checksum of the data being written.
+  Slice checksum;
+};
+
 // A file abstraction for sequential writing.  The implementation
 // must provide buffering since callers may append small fragments
 // at a time to the file.
@@ -769,6 +777,12 @@ class WritableFile {
   // PositionedAppend, so the users cannot mix the two.
   virtual Status Append(const Slice& data) = 0;
 
+  // Append data with verification information
+  virtual Status AppendWithVerify(
+      const Slice& data, const DataVerificationInfo& /* verification_info */) {
+    return Append(data);
+  }
+
   // PositionedAppend data to the specified offset. The new EOF after append
   // must be larger than the previous EOF. This is to be used when writes are
   // not backed by OS buffers and hence has to always start from the start of
@@ -795,6 +809,14 @@ class WritableFile {
         "WritableFile::PositionedAppend() not supported.");
   }
 
+  // PositionedAppend data with verification information.
+  virtual Status PositionedAppendWithVerify(
+      const Slice& /* data */, uint64_t /* offset */,
+      const DataVerificationInfo& /* verification_info */) {
+    return Status::NotSupported(
+        "WritableFile::PositionedAppend() not supported.");
+  }
+
   // Truncate is necessary to trim the file to the correct size
   // before closing. It is not always possible to keep track of the file
   // size due to whole pages writes. The behavior is undefined if called
@@ -1497,9 +1519,19 @@ class WritableFileWrapper : public WritableFile {
   explicit WritableFileWrapper(WritableFile* t) : target_(t) {}
 
   Status Append(const Slice& data) override { return target_->Append(data); }
+  Status AppendWithVerify(
+      const Slice& data,
+      const DataVerificationInfo& verification_info) override {
+    return target_->AppendWithVerify(data, verification_info);
+  }
   Status PositionedAppend(const Slice& data, uint64_t offset) override {
     return target_->PositionedAppend(data, offset);
   }
+  Status PositionedAppendWithVerify(
+      const Slice& data, uint64_t offset,
+      const DataVerificationInfo& verification_info) override {
+    return target_->PositionedAppendWithVerify(data, offset, verification_info);
+  }
   Status Truncate(uint64_t size) override { return target_->Truncate(size); }
   Status Close() override { return target_->Close(); }
   Status Flush() override { return target_->Flush(); }
diff --git a/include/rocksdb/file_system.h b/include/rocksdb/file_system.h
index 76009c2bb21..76ffd3f3159 100644
--- a/include/rocksdb/file_system.h
+++ b/include/rocksdb/file_system.h
@@ -749,6 +749,14 @@ class FSWritableFile {
   //
   // PositionedAppend() requires aligned buffer to be passed in. The alignment
   // required is queried via GetRequiredBufferAlignment()
+
+  // Append data with verification information
+  virtual IOStatus AppendWithVerify(
+      const Slice& data, const IOOptions& options, IODebugContext* dbg,
+      const DataVerificationInfo& /* verification_info */) {
+    return Append(data, options, dbg);
+  }
+
   virtual IOStatus PositionedAppend(const Slice& /* data */,
                                     uint64_t /* offset */,
                                     const IOOptions& /*options*/,
@@ -756,6 +764,14 @@ class FSWritableFile {
     return IOStatus::NotSupported();
   }
 
+  // PositionedAppend data with verification information.
+  virtual IOStatus PositionedAppendWithVerify(
+      const Slice& /* data */, uint64_t /* offset */,
+      const IOOptions& /*options*/, IODebugContext* /*dbg*/,
+      const DataVerificationInfo& /* verification_info */) {
+    return IOStatus::NotSupported();
+  }
+
   // Truncate is necessary to trim the file to the correct size
   // before closing. It is not always possible to keep track of the file
   // size due to whole pages writes. The behavior is undefined if called
@@ -1286,11 +1302,23 @@ class FSWritableFileWrapper : public FSWritableFile {
                   IODebugContext* dbg) override {
     return target_->Append(data, options, dbg);
   }
+  IOStatus AppendWithVerify(
+      const Slice& data, const IOOptions& options, IODebugContext* dbg,
+      const DataVerificationInfo& verification_info) override {
+    return target_->AppendWithVerify(data, options, dbg, verification_info);
+  }
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                             const IOOptions& options,
                             IODebugContext* dbg) override {
     return target_->PositionedAppend(data, offset, options, dbg);
   }
+  IOStatus PositionedAppendWithVerify(
+      const Slice& data, uint64_t offset, const IOOptions& options,
+      IODebugContext* dbg,
+      const DataVerificationInfo& verification_info) override {
+    return target_->PositionedAppendWithVerify(data, offset, options, dbg,
+                                               verification_info);
+  }
   IOStatus Truncate(uint64_t size, const IOOptions& options,
                     IODebugContext* dbg) override {
     return target_->Truncate(size, options, dbg);

From c8004745bdfe21f140982356388900e3416f5190 Mon Sep 17 00:00:00 2001
From: Zhichao Cao <zhichao@fb.com>
Date: Mon, 21 Sep 2020 18:25:17 -0700
Subject: [PATCH 2/3] Address the comments

---
 env/composite_env_wrapper.h    | 31 +++++++------------------------
 env/file_system_tracer.h       | 11 +++++++++++
 env/io_posix.h                 | 16 ++++++++++++++++
 include/rocksdb/env.h          | 32 --------------------------------
 include/rocksdb/file_system.h  | 33 ++++++++++++++++++++++-----------
 utilities/fault_injection_fs.h | 11 +++++++++++
 6 files changed, 67 insertions(+), 67 deletions(-)

diff --git a/env/composite_env_wrapper.h b/env/composite_env_wrapper.h
index 013b6cb4da6..2745f3fd2ff 100644
--- a/env/composite_env_wrapper.h
+++ b/env/composite_env_wrapper.h
@@ -115,26 +115,11 @@ class CompositeWritableFileWrapper : public WritableFile {
     IODebugContext dbg;
     return target_->Append(data, io_opts, &dbg);
   }
-  Status AppendWithVerify(
-      const Slice& data,
-      const DataVerificationInfo& verification_info) override {
-    IOOptions io_opts;
-    IODebugContext dbg;
-    return target_->AppendWithVerify(data, io_opts, &dbg, verification_info);
-  }
   Status PositionedAppend(const Slice& data, uint64_t offset) override {
     IOOptions io_opts;
     IODebugContext dbg;
     return target_->PositionedAppend(data, offset, io_opts, &dbg);
   }
-  Status PositionedAppendWithVerify(
-      const Slice& data, uint64_t offset,
-      const DataVerificationInfo& verification_info) override {
-    IOOptions io_opts;
-    IODebugContext dbg;
-    return target_->PositionedAppendWithVerify(data, offset, io_opts, &dbg,
-                                               verification_info);
-  }
   Status Truncate(uint64_t size) override {
     IOOptions io_opts;
     IODebugContext dbg;
@@ -742,23 +727,21 @@ class LegacyWritableFileWrapper : public FSWritableFile {
                   IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->Append(data));
   }
-  IOStatus AppendWithVerify(
-      const Slice& data, const IOOptions& /*options*/, IODebugContext* /*dbg*/,
-      const DataVerificationInfo& verification_info) override {
-    return status_to_io_status(
-        target_->AppendWithVerify(data, verification_info));
+  IOStatus Append(const Slice& data, const IOOptions& /*options*/,
+                  IODebugContext* /*dbg*/,
+                  const DataVerificationInfo& /*verification_info*/) override {
+    return status_to_io_status(target_->Append(data));
   }
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                             const IOOptions& /*options*/,
                             IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->PositionedAppend(data, offset));
   }
-  IOStatus PositionedAppendWithVerify(
+  IOStatus PositionedAppend(
       const Slice& data, uint64_t offset, const IOOptions& /*options*/,
       IODebugContext* /*dbg*/,
-      const DataVerificationInfo& verification_info) override {
-    return status_to_io_status(
-        target_->PositionedAppendWithVerify(data, offset, verification_info));
+      const DataVerificationInfo& /*verification_info*/) override {
+    return status_to_io_status(target_->PositionedAppend(data, offset));
   }
   IOStatus Truncate(uint64_t size, const IOOptions& /*options*/,
                     IODebugContext* /*dbg*/) override {
diff --git a/env/file_system_tracer.h b/env/file_system_tracer.h
index f18d4a1ff92..56fd0451a87 100644
--- a/env/file_system_tracer.h
+++ b/env/file_system_tracer.h
@@ -244,10 +244,21 @@ class FSWritableFileTracingWrapper : public FSWritableFileWrapper {
 
   IOStatus Append(const Slice& data, const IOOptions& options,
                   IODebugContext* dbg) override;
+  IOStatus Append(const Slice& data, const IOOptions& options,
+                  IODebugContext* dbg,
+                  const DataVerificationInfo& /*verification_info*/) override {
+    return Append(data, options, dbg);
+  }
 
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                             const IOOptions& options,
                             IODebugContext* dbg) override;
+  IOStatus PositionedAppend(
+      const Slice& data, uint64_t offset, const IOOptions& options,
+      IODebugContext* dbg,
+      const DataVerificationInfo& /*verification_info*/) override {
+    return PositionedAppend(data, offset, options, dbg);
+  }
 
   IOStatus Truncate(uint64_t size, const IOOptions& options,
                     IODebugContext* dbg) override;
diff --git a/env/io_posix.h b/env/io_posix.h
index 61d3cda9dd8..e09df25d1fc 100644
--- a/env/io_posix.h
+++ b/env/io_posix.h
@@ -242,9 +242,20 @@ class PosixWritableFile : public FSWritableFile {
   virtual IOStatus Close(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Append(const Slice& data, const IOOptions& opts,
                           IODebugContext* dbg) override;
+  virtual IOStatus Append(
+      const Slice& data, const IOOptions& opts, IODebugContext* dbg,
+      const DataVerificationInfo& /* verification_info */) override {
+    return Append(data, opts, dbg);
+  }
   virtual IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                                     const IOOptions& opts,
                                     IODebugContext* dbg) override;
+  virtual IOStatus PositionedAppend(
+      const Slice& data, uint64_t offset, const IOOptions& opts,
+      IODebugContext* dbg,
+      const DataVerificationInfo& /* verification_info */) override {
+    return PositionedAppend(data, offset, opts, dbg);
+  }
   virtual IOStatus Flush(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Sync(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Fsync(const IOOptions& opts, IODebugContext* dbg) override;
@@ -331,6 +342,11 @@ class PosixMmapFile : public FSWritableFile {
   virtual IOStatus Close(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Append(const Slice& data, const IOOptions& opts,
                           IODebugContext* dbg) override;
+  virtual IOStatus Append(
+      const Slice& data, const IOOptions& opts, IODebugContext* dbg,
+      const DataVerificationInfo& /* verification_info */) override {
+    return Append(data, opts, dbg);
+  }
   virtual IOStatus Flush(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Sync(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Fsync(const IOOptions& opts, IODebugContext* dbg) override;
diff --git a/include/rocksdb/env.h b/include/rocksdb/env.h
index 78fe7fc860c..955d591c310 100644
--- a/include/rocksdb/env.h
+++ b/include/rocksdb/env.h
@@ -740,14 +740,6 @@ class RandomAccessFile {
   // RandomAccessFileWrapper too.
 };
 
-// A data structure brings the data verification information, which is
-// used togther with data being written to a file.
-struct DataVerificationInfo {
-  DataVerificationInfo(const std::string& checksum_) : checksum(checksum_) {}
-  // checksum of the data being written.
-  Slice checksum;
-};
-
 // A file abstraction for sequential writing.  The implementation
 // must provide buffering since callers may append small fragments
 // at a time to the file.
@@ -777,12 +769,6 @@ class WritableFile {
   // PositionedAppend, so the users cannot mix the two.
   virtual Status Append(const Slice& data) = 0;
 
-  // Append data with verification information
-  virtual Status AppendWithVerify(
-      const Slice& data, const DataVerificationInfo& /* verification_info */) {
-    return Append(data);
-  }
-
   // PositionedAppend data to the specified offset. The new EOF after append
   // must be larger than the previous EOF. This is to be used when writes are
   // not backed by OS buffers and hence has to always start from the start of
@@ -809,14 +795,6 @@ class WritableFile {
         "WritableFile::PositionedAppend() not supported.");
   }
 
-  // PositionedAppend data with verification information.
-  virtual Status PositionedAppendWithVerify(
-      const Slice& /* data */, uint64_t /* offset */,
-      const DataVerificationInfo& /* verification_info */) {
-    return Status::NotSupported(
-        "WritableFile::PositionedAppend() not supported.");
-  }
-
   // Truncate is necessary to trim the file to the correct size
   // before closing. It is not always possible to keep track of the file
   // size due to whole pages writes. The behavior is undefined if called
@@ -1519,19 +1497,9 @@ class WritableFileWrapper : public WritableFile {
   explicit WritableFileWrapper(WritableFile* t) : target_(t) {}
 
   Status Append(const Slice& data) override { return target_->Append(data); }
-  Status AppendWithVerify(
-      const Slice& data,
-      const DataVerificationInfo& verification_info) override {
-    return target_->AppendWithVerify(data, verification_info);
-  }
   Status PositionedAppend(const Slice& data, uint64_t offset) override {
     return target_->PositionedAppend(data, offset);
   }
-  Status PositionedAppendWithVerify(
-      const Slice& data, uint64_t offset,
-      const DataVerificationInfo& verification_info) override {
-    return target_->PositionedAppendWithVerify(data, offset, verification_info);
-  }
   Status Truncate(uint64_t size) override { return target_->Truncate(size); }
   Status Close() override { return target_->Close(); }
   Status Flush() override { return target_->Flush(); }
diff --git a/include/rocksdb/file_system.h b/include/rocksdb/file_system.h
index 76ffd3f3159..f20e2547c76 100644
--- a/include/rocksdb/file_system.h
+++ b/include/rocksdb/file_system.h
@@ -702,6 +702,13 @@ class FSRandomAccessFile {
   // RandomAccessFileWrapper too.
 };
 
+// A data structure brings the data verification information, which is
+// used togther with data being written to a file.
+struct DataVerificationInfo {
+  // checksum of the data being written.
+  Slice checksum;
+};
+
 // A file abstraction for sequential writing.  The implementation
 // must provide buffering since callers may append small fragments
 // at a time to the file.
@@ -751,9 +758,11 @@ class FSWritableFile {
   // required is queried via GetRequiredBufferAlignment()
 
   // Append data with verification information
-  virtual IOStatus AppendWithVerify(
-      const Slice& data, const IOOptions& options, IODebugContext* dbg,
-      const DataVerificationInfo& /* verification_info */) {
+  // Note that this API change is experimental and it might be changed in
+  // the future. Currently, RocksDB does not use this API.
+  virtual IOStatus Append(const Slice& data, const IOOptions& options,
+                          IODebugContext* dbg,
+                          const DataVerificationInfo& /* verification_info */) {
     return Append(data, options, dbg);
   }
 
@@ -765,7 +774,9 @@ class FSWritableFile {
   }
 
   // PositionedAppend data with verification information.
-  virtual IOStatus PositionedAppendWithVerify(
+  // Note that this API change is experimental and it might be changed in
+  // the future. Currently, RocksDB does not use this API.
+  virtual IOStatus PositionedAppend(
       const Slice& /* data */, uint64_t /* offset */,
       const IOOptions& /*options*/, IODebugContext* /*dbg*/,
       const DataVerificationInfo& /* verification_info */) {
@@ -1302,22 +1313,22 @@ class FSWritableFileWrapper : public FSWritableFile {
                   IODebugContext* dbg) override {
     return target_->Append(data, options, dbg);
   }
-  IOStatus AppendWithVerify(
-      const Slice& data, const IOOptions& options, IODebugContext* dbg,
-      const DataVerificationInfo& verification_info) override {
-    return target_->AppendWithVerify(data, options, dbg, verification_info);
+  IOStatus Append(const Slice& data, const IOOptions& options,
+                  IODebugContext* dbg,
+                  const DataVerificationInfo& verification_info) override {
+    return target_->Append(data, options, dbg, verification_info);
   }
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                             const IOOptions& options,
                             IODebugContext* dbg) override {
     return target_->PositionedAppend(data, offset, options, dbg);
   }
-  IOStatus PositionedAppendWithVerify(
+  IOStatus PositionedAppend(
       const Slice& data, uint64_t offset, const IOOptions& options,
       IODebugContext* dbg,
       const DataVerificationInfo& verification_info) override {
-    return target_->PositionedAppendWithVerify(data, offset, options, dbg,
-                                               verification_info);
+    return target_->PositionedAppend(data, offset, options, dbg,
+                                     verification_info);
   }
   IOStatus Truncate(uint64_t size, const IOOptions& options,
                     IODebugContext* dbg) override {
diff --git a/utilities/fault_injection_fs.h b/utilities/fault_injection_fs.h
index d856cba5dbe..2a233a3fd5b 100644
--- a/utilities/fault_injection_fs.h
+++ b/utilities/fault_injection_fs.h
@@ -64,6 +64,11 @@ class TestFSWritableFile : public FSWritableFile {
   virtual ~TestFSWritableFile();
   virtual IOStatus Append(const Slice& data, const IOOptions&,
                           IODebugContext*) override;
+  virtual IOStatus Append(
+      const Slice& data, const IOOptions& options, IODebugContext* dbg,
+      const DataVerificationInfo& /*verification_info*/) override {
+    return Append(data, options, dbg);
+  }
   virtual IOStatus Truncate(uint64_t size, const IOOptions& options,
                             IODebugContext* dbg) override {
     return target_->Truncate(size, options, dbg);
@@ -78,6 +83,12 @@ class TestFSWritableFile : public FSWritableFile {
                                     IODebugContext* dbg) override {
     return target_->PositionedAppend(data, offset, options, dbg);
   }
+  IOStatus PositionedAppend(
+      const Slice& data, uint64_t offset, const IOOptions& options,
+      IODebugContext* dbg,
+      const DataVerificationInfo& /*verification_info*/) override {
+    return PositionedAppend(data, offset, options, dbg);
+  }
   virtual size_t GetRequiredBufferAlignment() const override {
     return target_->GetRequiredBufferAlignment();
   }

From 0dc5f5f797704b77cc54e04414835975197a668a Mon Sep 17 00:00:00 2001
From: Zhichao Cao <zhichao@fb.com>
Date: Wed, 23 Sep 2020 14:50:41 -0700
Subject: [PATCH 3/3] move the DataVerificationInfo before debug

---
 env/composite_env_wrapper.h    | 12 +++++-----
 env/file_system_tracer.h       | 12 +++++-----
 env/io_posix.h                 | 16 ++++++-------
 include/rocksdb/file_system.h  | 44 ++++++++++++++++++----------------
 utilities/fault_injection_fs.h | 14 +++++------
 5 files changed, 50 insertions(+), 48 deletions(-)

diff --git a/env/composite_env_wrapper.h b/env/composite_env_wrapper.h
index 2745f3fd2ff..7a0da5c3e26 100644
--- a/env/composite_env_wrapper.h
+++ b/env/composite_env_wrapper.h
@@ -728,8 +728,8 @@ class LegacyWritableFileWrapper : public FSWritableFile {
     return status_to_io_status(target_->Append(data));
   }
   IOStatus Append(const Slice& data, const IOOptions& /*options*/,
-                  IODebugContext* /*dbg*/,
-                  const DataVerificationInfo& /*verification_info*/) override {
+                  const DataVerificationInfo& /*verification_info*/,
+                  IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->Append(data));
   }
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
@@ -737,10 +737,10 @@ class LegacyWritableFileWrapper : public FSWritableFile {
                             IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->PositionedAppend(data, offset));
   }
-  IOStatus PositionedAppend(
-      const Slice& data, uint64_t offset, const IOOptions& /*options*/,
-      IODebugContext* /*dbg*/,
-      const DataVerificationInfo& /*verification_info*/) override {
+  IOStatus PositionedAppend(const Slice& data, uint64_t offset,
+                            const IOOptions& /*options*/,
+                            const DataVerificationInfo& /*verification_info*/,
+                            IODebugContext* /*dbg*/) override {
     return status_to_io_status(target_->PositionedAppend(data, offset));
   }
   IOStatus Truncate(uint64_t size, const IOOptions& /*options*/,
diff --git a/env/file_system_tracer.h b/env/file_system_tracer.h
index 56fd0451a87..4f37cbb0f2b 100644
--- a/env/file_system_tracer.h
+++ b/env/file_system_tracer.h
@@ -245,18 +245,18 @@ class FSWritableFileTracingWrapper : public FSWritableFileWrapper {
   IOStatus Append(const Slice& data, const IOOptions& options,
                   IODebugContext* dbg) override;
   IOStatus Append(const Slice& data, const IOOptions& options,
-                  IODebugContext* dbg,
-                  const DataVerificationInfo& /*verification_info*/) override {
+                  const DataVerificationInfo& /*verification_info*/,
+                  IODebugContext* dbg) override {
     return Append(data, options, dbg);
   }
 
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                             const IOOptions& options,
                             IODebugContext* dbg) override;
-  IOStatus PositionedAppend(
-      const Slice& data, uint64_t offset, const IOOptions& options,
-      IODebugContext* dbg,
-      const DataVerificationInfo& /*verification_info*/) override {
+  IOStatus PositionedAppend(const Slice& data, uint64_t offset,
+                            const IOOptions& options,
+                            const DataVerificationInfo& /*verification_info*/,
+                            IODebugContext* dbg) override {
     return PositionedAppend(data, offset, options, dbg);
   }
 
diff --git a/env/io_posix.h b/env/io_posix.h
index e09df25d1fc..2d8e83c9d79 100644
--- a/env/io_posix.h
+++ b/env/io_posix.h
@@ -242,9 +242,9 @@ class PosixWritableFile : public FSWritableFile {
   virtual IOStatus Close(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Append(const Slice& data, const IOOptions& opts,
                           IODebugContext* dbg) override;
-  virtual IOStatus Append(
-      const Slice& data, const IOOptions& opts, IODebugContext* dbg,
-      const DataVerificationInfo& /* verification_info */) override {
+  virtual IOStatus Append(const Slice& data, const IOOptions& opts,
+                          const DataVerificationInfo& /* verification_info */,
+                          IODebugContext* dbg) override {
     return Append(data, opts, dbg);
   }
   virtual IOStatus PositionedAppend(const Slice& data, uint64_t offset,
@@ -252,8 +252,8 @@ class PosixWritableFile : public FSWritableFile {
                                     IODebugContext* dbg) override;
   virtual IOStatus PositionedAppend(
       const Slice& data, uint64_t offset, const IOOptions& opts,
-      IODebugContext* dbg,
-      const DataVerificationInfo& /* verification_info */) override {
+      const DataVerificationInfo& /* verification_info */,
+      IODebugContext* dbg) override {
     return PositionedAppend(data, offset, opts, dbg);
   }
   virtual IOStatus Flush(const IOOptions& opts, IODebugContext* dbg) override;
@@ -342,9 +342,9 @@ class PosixMmapFile : public FSWritableFile {
   virtual IOStatus Close(const IOOptions& opts, IODebugContext* dbg) override;
   virtual IOStatus Append(const Slice& data, const IOOptions& opts,
                           IODebugContext* dbg) override;
-  virtual IOStatus Append(
-      const Slice& data, const IOOptions& opts, IODebugContext* dbg,
-      const DataVerificationInfo& /* verification_info */) override {
+  virtual IOStatus Append(const Slice& data, const IOOptions& opts,
+                          const DataVerificationInfo& /* verification_info */,
+                          IODebugContext* dbg) override {
     return Append(data, opts, dbg);
   }
   virtual IOStatus Flush(const IOOptions& opts, IODebugContext* dbg) override;
diff --git a/include/rocksdb/file_system.h b/include/rocksdb/file_system.h
index f20e2547c76..3683491c1ba 100644
--- a/include/rocksdb/file_system.h
+++ b/include/rocksdb/file_system.h
@@ -736,6 +736,16 @@ class FSWritableFile {
   virtual IOStatus Append(const Slice& data, const IOOptions& options,
                           IODebugContext* dbg) = 0;
 
+  // EXPERIMENTAL / CURRENTLY UNUSED
+  // Append data with verification information
+  // Note that this API change is experimental and it might be changed in
+  // the future. Currently, RocksDB does not use this API.
+  virtual IOStatus Append(const Slice& data, const IOOptions& options,
+                          const DataVerificationInfo& /* verification_info */,
+                          IODebugContext* dbg) {
+    return Append(data, options, dbg);
+  }
+
   // PositionedAppend data to the specified offset. The new EOF after append
   // must be larger than the previous EOF. This is to be used when writes are
   // not backed by OS buffers and hence has to always start from the start of
@@ -756,16 +766,6 @@ class FSWritableFile {
   //
   // PositionedAppend() requires aligned buffer to be passed in. The alignment
   // required is queried via GetRequiredBufferAlignment()
-
-  // Append data with verification information
-  // Note that this API change is experimental and it might be changed in
-  // the future. Currently, RocksDB does not use this API.
-  virtual IOStatus Append(const Slice& data, const IOOptions& options,
-                          IODebugContext* dbg,
-                          const DataVerificationInfo& /* verification_info */) {
-    return Append(data, options, dbg);
-  }
-
   virtual IOStatus PositionedAppend(const Slice& /* data */,
                                     uint64_t /* offset */,
                                     const IOOptions& /*options*/,
@@ -773,13 +773,15 @@ class FSWritableFile {
     return IOStatus::NotSupported();
   }
 
+  // EXPERIMENTAL / CURRENTLY UNUSED
   // PositionedAppend data with verification information.
   // Note that this API change is experimental and it might be changed in
   // the future. Currently, RocksDB does not use this API.
   virtual IOStatus PositionedAppend(
       const Slice& /* data */, uint64_t /* offset */,
-      const IOOptions& /*options*/, IODebugContext* /*dbg*/,
-      const DataVerificationInfo& /* verification_info */) {
+      const IOOptions& /*options*/,
+      const DataVerificationInfo& /* verification_info */,
+      IODebugContext* /*dbg*/) {
     return IOStatus::NotSupported();
   }
 
@@ -1314,21 +1316,21 @@ class FSWritableFileWrapper : public FSWritableFile {
     return target_->Append(data, options, dbg);
   }
   IOStatus Append(const Slice& data, const IOOptions& options,
-                  IODebugContext* dbg,
-                  const DataVerificationInfo& verification_info) override {
-    return target_->Append(data, options, dbg, verification_info);
+                  const DataVerificationInfo& verification_info,
+                  IODebugContext* dbg) override {
+    return target_->Append(data, options, verification_info, dbg);
   }
   IOStatus PositionedAppend(const Slice& data, uint64_t offset,
                             const IOOptions& options,
                             IODebugContext* dbg) override {
     return target_->PositionedAppend(data, offset, options, dbg);
   }
-  IOStatus PositionedAppend(
-      const Slice& data, uint64_t offset, const IOOptions& options,
-      IODebugContext* dbg,
-      const DataVerificationInfo& verification_info) override {
-    return target_->PositionedAppend(data, offset, options, dbg,
-                                     verification_info);
+  IOStatus PositionedAppend(const Slice& data, uint64_t offset,
+                            const IOOptions& options,
+                            const DataVerificationInfo& verification_info,
+                            IODebugContext* dbg) override {
+    return target_->PositionedAppend(data, offset, options, verification_info,
+                                     dbg);
   }
   IOStatus Truncate(uint64_t size, const IOOptions& options,
                     IODebugContext* dbg) override {
diff --git a/utilities/fault_injection_fs.h b/utilities/fault_injection_fs.h
index 2a233a3fd5b..4c4a1612b85 100644
--- a/utilities/fault_injection_fs.h
+++ b/utilities/fault_injection_fs.h
@@ -64,9 +64,9 @@ class TestFSWritableFile : public FSWritableFile {
   virtual ~TestFSWritableFile();
   virtual IOStatus Append(const Slice& data, const IOOptions&,
                           IODebugContext*) override;
-  virtual IOStatus Append(
-      const Slice& data, const IOOptions& options, IODebugContext* dbg,
-      const DataVerificationInfo& /*verification_info*/) override {
+  virtual IOStatus Append(const Slice& data, const IOOptions& options,
+                          const DataVerificationInfo& /*verification_info*/,
+                          IODebugContext* dbg) override {
     return Append(data, options, dbg);
   }
   virtual IOStatus Truncate(uint64_t size, const IOOptions& options,
@@ -83,10 +83,10 @@ class TestFSWritableFile : public FSWritableFile {
                                     IODebugContext* dbg) override {
     return target_->PositionedAppend(data, offset, options, dbg);
   }
-  IOStatus PositionedAppend(
-      const Slice& data, uint64_t offset, const IOOptions& options,
-      IODebugContext* dbg,
-      const DataVerificationInfo& /*verification_info*/) override {
+  IOStatus PositionedAppend(const Slice& data, uint64_t offset,
+                            const IOOptions& options,
+                            const DataVerificationInfo& /*verification_info*/,
+                            IODebugContext* dbg) override {
     return PositionedAppend(data, offset, options, dbg);
   }
   virtual size_t GetRequiredBufferAlignment() const override {