On 2013-09-13 23:09, sog@msg.com.mx wrote:

If the call fails because O_DIRECT, in a "tmpfs" in my Fedora 19 '/tmp', the file is left created anyway! so the retry fails because O_EXCL|O_CREAT.

Also on RHEL 6.4 (2.6.32-358.18.1.el6.x86_64) with /dev/shm/nosuch. I'll report it to RedHat and see what they say.

I propose the following: (...)

• * Fortunately seems that other errors are reported before EINVAL
  

• * So, we need to remove it before retry open.
   */
  if (newfd == INVALID_HANDLE_VALUE && ErrCode() == EINVAL)
  

•    (void)unlink(lpath)  ,
  

No unlink(). EINVAL does not say whether the file existed before the call. Not on another OS, nor on another Linux version or filesystem where Linux may work differently.

Somewhat better: #ifdef <buggy Linux>, replace O_EXCL with O_TRUNC in the 2nd call. Or add paranoia like taking an exclusive lock, but ignore "locking not supported" errors.

#endif newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666); #endif