Re: (ITS#7682) LMDB: [PATCH] mdb_env_copy should retry open() if O_DIRECT fails

[h.b.furuseth@usit.uio.no]

I wrote:
> 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.

https://bugzilla.redhat.com/show_bug.cgi?id=1008073

Simpler fix, at least on Linux:

#ifdef O_DIRECT
	if ((rc = fcntl(fd, F_GETFL)) != -1)
		(void) fcntl(fd, F_SETFL, rc | O_DIRECT);
#endif

But that could fail elsewhere, if some OS only accepts
O_DIRECT to open() and not to fcntl().

BTW, does the nearby Apple code need to fail if
fcntl(newfd, F_NOCACHE, 1) fails? Could ignore errors.

-- 
Hallvard