From d52df9352c320f6e76591a0bd737984fc200b06f Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Sat, 13 Apr 2019 13:46:56 +0300
Subject: [PATCH] fs::rename, use renameat2 on Linux

---
 Utilities/File.cpp | 25 +++++++++++++++++++++----
 Utilities/File.h   |  2 +-
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/Utilities/File.cpp b/Utilities/File.cpp
index 52e43da2c2..0a5ef837b6 100644
--- a/Utilities/File.cpp
+++ b/Utilities/File.cpp
@@ -137,6 +137,8 @@ static fs::error to_error(DWORD e)
 #include <mach-o/dyld.h>
 #elif defined(__linux__) || defined(__sun)
 #include <sys/sendfile.h>
+#include <sys/syscall.h>
+#include <linux/fs.h>
 #else
 #include <fstream>
 #endif
@@ -192,7 +194,7 @@ namespace fs
 		// Do notning
 	}
 
-	native_handle file_base::get_native_handle()
+	fs::native_handle fs::file_base::get_handle()
 	{
 #ifdef _WIN32
 		return INVALID_HANDLE_VALUE;
@@ -609,6 +611,21 @@ bool fs::rename(const std::string& from, const std::string& to, bool overwrite)
 
 	return true;
 #else
+
+#ifdef __linux__
+	if (syscall(SYS_renameat2, AT_FDCWD, from.c_str(), AT_FDCWD, to.c_str(), overwrite ? 0 : 1 /* RENAME_NOREPLACE */) == 0)
+	{
+		return true;
+	}
+
+	// If the filesystem doesn't support RENAME_NOREPLACE, it returns EINVAL. Retry with fallback method in that case.
+	if (errno != EINVAL || overwrite)
+	{
+		g_tls_error = to_error(errno);
+		return false;
+	}
+#endif
+
 	if (!overwrite && exists(to))
 	{
 		g_tls_error = fs::error::exist;
@@ -996,7 +1013,7 @@ fs::file::file(const std::string& path, bs_t<open_mode> mode)
 			return size.QuadPart;
 		}
 
-		native_handle get_native_handle() override
+		native_handle get_handle() override
 		{
 			return m_handle;
 		}
@@ -1136,7 +1153,7 @@ fs::file::file(const std::string& path, bs_t<open_mode> mode)
 			return file_info.st_size;
 		}
 
-		native_handle get_native_handle() override
+		native_handle get_handle() override
 		{
 			return m_fd;
 		}
@@ -1219,7 +1236,7 @@ fs::native_handle fs::file::get_handle() const
 {
 	if (m_file)
 	{
-		return m_file->get_native_handle();
+		return m_file->get_handle();
 	}
 
 #ifdef _WIN32
diff --git a/Utilities/File.h b/Utilities/File.h
index 641fc954ee..fa434dee6d 100644
--- a/Utilities/File.h
+++ b/Utilities/File.h
@@ -77,7 +77,7 @@ namespace fs
 		virtual u64 write(const void* buffer, u64 size) = 0;
 		virtual u64 seek(s64 offset, seek_mode whence) = 0;
 		virtual u64 size() = 0;
-		virtual native_handle get_native_handle();
+		virtual native_handle get_handle();
 	};
 
 	// Directory entry (TODO)