[OpenAFS-devel] The ihandle sync thing

[chas williams - CONTRACTOR]

On Thu, 28 Mar 2013 13:47:18 -0400
Garrett Wollman <wollman@csail.mit.edu> wrote:

> I don't think that even with _POSIX_SYNCHRONIZED_IO the requirements
> are tight enough to be truly useful -- just in the past week there has
> been a discussion in the Austin Group about whether the Standard
> actually requires that fsync() on a newly-created file actually ensure
> that the directory entries for that file be committed to storage.

I doesn't really matter what you think it should be, Linux doesn't do
that. From the fsync() man page:

       Calling fsync() does not necessarily ensure that the entry in the
       directory containing the file has  also  reached  disk.  For that
       an explicit fsync() on a file descriptor for the directory is also
       needed.

So, I think that is mildly interesting when you think about the namei
fileserver's operation.  I don't think it ever sync's the underlying
filesystem's parent directory for the vnode's (vnode's being either a
file or directory).  It seems like this might be a problem for vnode
creation and deletion.