kernel: implement POSIX fsync through the shared file API

src/common/platform/sysLinuxFileIO.cpp

@@ -367,7 +367,7 @@ bool SysFileDeleteFile(const std::filesystem::path& name) {
 
 bool SysFileFlush(sys_file_t& f) {
 	if (f.type == SYS_FILE_FILE && f.f != nullptr) {
-		return (fflush(f.f) == 0);
+		return fflush(f.f) == 0 && fsync(fileno(f.f)) == 0;
 	}
 
 	return false;

src/kernel/fileSystem.cpp

@@ -1326,6 +1326,27 @@ int KYTY_SYSV_ABI KernelFtruncate(int d, int64_t length) {
 	return OK;
 }
 
+int KYTY_SYSV_ABI KernelFsync(int d) {
+	PRINT_NAME();
+
+	if (d < DESCRIPTOR_MIN) {
+		return KERNEL_ERROR_EBADF;
+	}
+
+	auto* file = g_files->GetFile(d);
+	if (file == nullptr || !file->opened) {
+		return KERNEL_ERROR_EBADF;
+	}
+
+	Common::LockGuard lock(file->mutex);
+	if (file->f.IsInvalid() || !file->f.Flush()) {
+		return KERNEL_ERROR_EIO;
+	}
+
+	LOGF("\tFsync: %s\n", Common::PathToString(file->real_name).c_str());
+	return OK;
+}
+
 int KYTY_SYSV_ABI KernelUnlink(const char* path) {
 	PRINT_NAME();
 

src/kernel/fileSystem.h

@@ -72,6 +72,7 @@ int KYTY_SYSV_ABI     KernelStat(const char* path, FileStat* sb);
 int KYTY_SYSV_ABI     KernelFstat(int d, FileStat* sb);
 int KYTY_SYSV_ABI     KernelTruncate(const char* path, int64_t length);
 int KYTY_SYSV_ABI     KernelFtruncate(int d, int64_t length);
+int KYTY_SYSV_ABI     KernelFsync(int d);
 int KYTY_SYSV_ABI     KernelUnlink(const char* path);
 int KYTY_SYSV_ABI     KernelRename(const char* from, const char* to);
 int KYTY_SYSV_ABI     KernelGetdirentries(int fd, char* buf, int nbytes, int64_t* basep);

src/libs/libKernel.cpp

@@ -1341,14 +1341,6 @@ static int KYTY_SYSV_ABI KernelGetOperationMode(int* mode, int* submode) {
 	return OK;
 }
 
-static int KYTY_SYSV_ABI KernelFsync(int fd) {
-	PRINT_NAME();
-
-	LOGF("\t fd = %d\n", fd);
-
-	return OK;
-}
-
 static void KYTY_SYSV_ABI KernelSync() {
 	PRINT_NAME();
 }
@@ -1986,6 +1978,12 @@ int KYTY_SYSV_ABI ftruncate(int d, int64_t length) {
 	return POSIX_CALL(LibKernel::FileSystem::KernelFtruncate(d, length));
 }
 
+int KYTY_SYSV_ABI fsync(int d) {
+	PRINT_NAME();
+
+	return POSIX_CALL(LibKernel::FileSystem::KernelFsync(d));
+}
+
 int KYTY_SYSV_ABI socket(int family, int type, int protocol) {
 	PRINT_NAME();
 	return Network::Net::Socket(family, type, protocol);
@@ -2174,6 +2172,7 @@ LIB_DEFINE(InitLibKernel_1_Posix) {
 	LIB_FUNC("E6ao34wPw+U", stat);
 	LIB_FUNC("JGMio+21L4c", mkdir);
 	LIB_FUNC("ih4CD9-gghM", Posix::ftruncate);
+	LIB_FUNC("juWbTNM+8hw", Posix::fsync);
 	LIB_FUNC("8nY19bKoiZk", Posix::fcntl);
 	LIB_FUNC("pDuPEf3m4fI", Posix::sem_init);
 	LIB_FUNC("cDW233RAwWo", Posix::sem_destroy);
@@ -3394,7 +3393,7 @@ LIB_DEFINE(InitLibKernel_1) {
 	LIB_FUNC("959qrazPIrg", LibKernel::KernelGetProcParam);
 	LIB_FUNC("tU5e3f9gSiU", LibKernel::KernelIsTrinityMode);
 	LIB_FUNC("NH6xARDOVv8", LibKernel::KernelGetOperationMode);
-	LIB_FUNC("fTx66l5iWIA", LibKernel::KernelFsync);
+	LIB_FUNC("fTx66l5iWIA", FileSystem::KernelFsync);
 	LIB_FUNC("uvT2iYBBnkY", LibKernel::KernelSync);
 	LIB_FUNC("HoLVWNanBBc", LibKernel::getpid);
 	LIB_FUNC("9BcDykPmo1I", LibKernel::get_error_addr);