On Thu, Sep 17, 2020 at 04:09:12PM +0200, Christoph Hellwig wrote:
> On Thu, Sep 17, 2020 at 01:28:29PM +0200, Ævar Arnfjörð Bjarmason wrote:
> > Change the behavior of core.fsyncObjectFiles to also sync the
> > directory entry. I don't have a case where this broke, just going by
> > paranoia and the fsync(2) manual page's guarantees about its behavior.
>
> It is not just paranoia, but indeed what is required from the standards
> POV. At least for many Linux file systems your second fsync will be
> very cheap (basically a NULL syscall) as the log has alredy been forced
> all the way by the first one, but you can't rely on that.
Is it sufficient to fsync() just the surrounding directory? I.e., if I
do:
mkdir("a");
mkdir("a/b");
open("a/b/c", O_WRONLY);
is it enough to fsync() a descriptor pointing to "a/b", or should I
also do "a"?
-Peff
