diff --git a/src/flatfile.h b/src/flatfile.h
--- a/src/flatfile.h
+++ b/src/flatfile.h
@@ -23,12 +23,10 @@
         READWRITE(VARINT(nPos));
     }
 
-    FlatFilePos() { SetNull(); }
+    FlatFilePos() : nFile(-1), nPos(0) {}
 
-    FlatFilePos(int nFileIn, unsigned int nPosIn) {
-        nFile = nFileIn;
-        nPos = nPosIn;
-    }
+    FlatFilePos(int nFileIn, unsigned int nPosIn)
+        : nFile(nFileIn), nPos(nPosIn) {}
 
     friend bool operator==(const FlatFilePos &a, const FlatFilePos &b) {
         return (a.nFile == b.nFile && a.nPos == b.nPos);
@@ -72,7 +70,7 @@
     fs::path FileName(const FlatFilePos &pos) const;
 
     /** Open a handle to the file at the given position. */
-    FILE *Open(const FlatFilePos &pos, bool fReadOnly = false);
+    FILE *Open(const FlatFilePos &pos, bool read_only = false);
 
     /**
      * Allocate additional space in a file after the given starting position.
diff --git a/src/flatfile.cpp b/src/flatfile.cpp
--- a/src/flatfile.cpp
+++ b/src/flatfile.cpp
@@ -25,25 +25,25 @@
     return m_dir / strprintf("%s%05u.dat", m_prefix, pos.nFile);
 }
 
-FILE *FlatFileSeq::Open(const FlatFilePos &pos, bool fReadOnly) {
-    if (pos.IsNull()) return nullptr;
+FILE *FlatFileSeq::Open(const FlatFilePos &pos, bool read_only) {
+    if (pos.IsNull()) {
+        return nullptr;
+    }
     fs::path path = FileName(pos);
     fs::create_directories(path.parent_path());
-    FILE *file = fsbridge::fopen(path, fReadOnly ? "rb" : "rb+");
-    if (!file && !fReadOnly) {
+    FILE *file = fsbridge::fopen(path, read_only ? "rb" : "rb+");
+    if (!file && !read_only) {
         file = fsbridge::fopen(path, "wb+");
     }
     if (!file) {
         LogPrintf("Unable to open file %s\n", path.string());
         return nullptr;
     }
-    if (pos.nPos) {
-        if (fseek(file, pos.nPos, SEEK_SET)) {
-            LogPrintf("Unable to seek to position %u of %s\n", pos.nPos,
-                      path.string());
-            fclose(file);
-            return nullptr;
-        }
+    if (pos.nPos && fseek(file, pos.nPos, SEEK_SET)) {
+        LogPrintf("Unable to seek to position %u of %s\n", pos.nPos,
+                  path.string());
+        fclose(file);
+        return nullptr;
     }
     return file;
 }
diff --git a/src/util.h b/src/util.h
--- a/src/util.h
+++ b/src/util.h
@@ -75,7 +75,7 @@
 bool LockDirectory(const fs::path &directory, const std::string lockfile_name,
                    bool probe_only = false);
 bool DirIsWritable(const fs::path &directory);
-bool CheckDiskSpace(const fs::path &dir, uint64_t nAdditionalBytes = 0);
+bool CheckDiskSpace(const fs::path &dir, uint64_t additional_bytes = 0);
 
 /**
  * Release all directory locks. This is used for unit testing only, at runtime
diff --git a/src/util.cpp b/src/util.cpp
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -203,12 +203,12 @@
     return true;
 }
 
-bool CheckDiskSpace(const fs::path &dir, uint64_t nAdditionalBytes) {
+bool CheckDiskSpace(const fs::path &dir, uint64_t additional_bytes) {
     // 50 MiB
-    constexpr uint64_t nMinDiskSpace = 52428800;
+    constexpr uint64_t min_disk_space = 52428800;
 
-    uint64_t nFreeBytesAvailable = fs::space(dir).available;
-    return nFreeBytesAvailable >= nMinDiskSpace + nAdditionalBytes;
+    uint64_t free_bytes_available = fs::space(dir).available;
+    return free_bytes_available >= min_disk_space + additional_bytes;
 }
 
 /**