ceph/src/common/sync_filesystem.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2011 New Dream Network
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #ifndef CEPH_SYNC_FILESYSTEM_H
  16 #define CEPH_SYNC_FILESYSTEM_H
  17
  18 #include <unistd.h>
  19
  20 #if defined(__linux__)
  21 #include <sys/ioctl.h>
  22 #include <syscall.h>
  23 #include "os/fs/btrfs_ioctl.h"
  24 #endif
  25
  26 inline int sync_filesystem(int fd)
  27 {
  28   /* On Linux, newer versions of glibc have a function called syncfs that
  29    * performs a sync on only one filesystem. If we don't have this call, we
  30    * have to fall back on sync(), which synchronizes every filesystem on the
  31    * computer. */
  32 #ifdef HAVE_SYS_SYNCFS
  33   if (syncfs(fd) == 0)
  34     return 0;
  35 #elif defined(SYS_syncfs)
  36   if (syscall(SYS_syncfs, fd) == 0)
  37     return 0;
  38 #elif defined(__NR_syncfs)
  39   if (syscall(__NR_syncfs, fd) == 0)
  40     return 0;
  41 #endif
  42
  43 #if defined(HAVE_SYS_SYNCFS) || defined(SYS_syncfs) || defined(__NR_syncfs)
  44   else if (errno == ENOSYS) {
  45     sync();
  46     return 0;
  47   } else {
  48     return -errno;
  49   }
  50 #else
  51   sync();
  52   return 0;
  53 #endif
  54 }
  55
  56 #endif