/* vi: set sw=4 ts=4: *//* * flushb.c --- Hides system-dependent information for both syncing a *	device to disk and to flush any buffers from disk cache. * * Copyright (C) 2000 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */#include <stdio.h>#if HAVE_ERRNO_H#include <errno.h>#endif#if HAVE_UNISTD_H#include <unistd.h>#endif#if HAVE_SYS_IOCTL_H#include <sys/ioctl.h>#endif#if HAVE_SYS_MOUNT_H#include <sys/param.h>#include <sys/mount.h>		/* This may define BLKFLSBUF */#endif#include "ext2_fs.h"#include "ext2fs.h"/* * For Linux, define BLKFLSBUF and FDFLUSH if necessary, since * not all portable header file does so for us.  This really should be * fixed in the glibc header files.  (Recent glibcs appear to define * BLKFLSBUF in sys/mount.h, but FDFLUSH still doesn't seem to be * defined anywhere portable.)  Until then.... */#ifdef __linux__#ifndef BLKFLSBUF#define BLKFLSBUF	_IO(0x12,97)	/* flush buffer cache */#endif#ifndef FDFLUSH#define FDFLUSH		_IO(2,0x4b)	/* flush floppy disk */#endif#endif/* * This function will sync a device/file, and optionally attempt to * flush the buffer cache.  The latter is basically only useful for * system benchmarks and for torturing systems in burn-in tests.  :) */errcode_t ext2fs_sync_device(int fd, int flushb){	/*	 * We always sync the device in case we're running on old	 * kernels for which we can lose data if we don't.  (There	 * still is a race condition for those kernels, but this	 * reduces it greatly.)	 */	if (fsync (fd) == -1)		return errno;	if (flushb) {#ifdef BLKFLSBUF		if (ioctl (fd, BLKFLSBUF, 0) == 0)			return 0;#else#ifdef __GNUC__# warning BLKFLSBUF not defined#endif /* __GNUC__ */#endif#ifdef FDFLUSH		ioctl (fd, FDFLUSH, 0);   /* In case this is a floppy */#else#ifdef __GNUC__# warning FDFLUSH not defined#endif /* __GNUC__ */#endif	}	return 0;}