common: fs: file: Revert Flush to its previous behavior and add Commit

It became apparent that logging can continuously spam errors that trigger file flushing.
Since committing the files to disk is an expensive operation, this causes unnecessarily high disk usage.
As such, we will revert Flush() to the previous behavior and add a Commit() member function in the event that this behavior is needed.

2 files changed, 34 insertions, 3 deletions

diff --git a/src/common/fs/file.cpp b/src/common/fs/file.cpp
index 022780e4e..274f57659 100644
--- a/src/common/fs/file.cpp
+++ b/src/common/fs/file.cpp
@@ -306,9 +306,9 @@ bool IOFile::Flush() const {
     errno = 0;
 
 #ifdef _WIN32
-    const auto flush_result = std::fflush(file) == 0 && _commit(fileno(file)) == 0;
+    const auto flush_result = std::fflush(file) == 0;
 #else
-    const auto flush_result = std::fflush(file) == 0 && fsync(fileno(file)) == 0;
+    const auto flush_result = std::fflush(file) == 0;
 #endif
 
     if (!flush_result) {
@@ -320,6 +320,28 @@ bool IOFile::Flush() const {
     return flush_result;
 }
 
+bool IOFile::Commit() const {
+    if (!IsOpen()) {
+        return false;
+    }
+
+    errno = 0;
+
+#ifdef _WIN32
+    const auto commit_result = std::fflush(file) == 0 && _commit(fileno(file)) == 0;
+#else
+    const auto commit_result = std::fflush(file) == 0 && fsync(fileno(file)) == 0;
+#endif
+
+    if (!commit_result) {
+        const auto ec = std::error_code{errno, std::generic_category()};
+        LOG_ERROR(Common_Filesystem, "Failed to commit the file at path={}, ec_message={}",
+                  PathToUTF8String(file_path), ec.message());
+    }
+
+    return commit_result;
+}
+
 bool IOFile::SetSize(u64 size) const {
     if (!IsOpen()) {
         return false;
diff --git a/src/common/fs/file.h b/src/common/fs/file.h
index 588fe619d..2c4ab4332 100644
--- a/src/common/fs/file.h
+++ b/src/common/fs/file.h
@@ -396,13 +396,22 @@ public:
     [[nodiscard]] size_t WriteString(std::span<const char> string) const;
 
     /**
-     * Attempts to flush any unwritten buffered data into the file and flush the file into the disk.
+     * Attempts to flush any unwritten buffered data into the file.
      *
      * @returns True if the flush was successful, false otherwise.
      */
     bool Flush() const;
 
     /**
+     * Attempts to commit the file into the disk.
+     * Note that this is an expensive operation as this forces the operating system to write
+     * the contents of the file associated with the file descriptor into the disk.
+     *
+     * @returns True if the commit was successful, false otherwise.
+     */
+    bool Commit() const;
+
+    /**
      * Resizes the file to a given size.
      * If the file is resized to a smaller size, the remainder of the file is discarded.
      * If the file is resized to a larger size, the new area appears as if zero-filled.