83 lines
1.9 KiB
C
83 lines
1.9 KiB
C
/*
|
|
* 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;
|
|
}
|