Slowdown when copying large files (PR#8617)

[Brett Worth]

> } Apparently not - according to one of JohnT's technical
> } contacts at MS - doing a fsync on a file in NT isn't the
> } same as a UNIX fsync, but only *schedules the write to
> } be done* !
> 
> So it's more like the way NFS treats syncs.  Eventually... :-)

I believe that NFS will not return untill the write is done.
I think Jeremy's exclaimation is related to the fact the you 
have asked for a fsync for what is possibly a very good reason
and it's not really being done.

> Sounds to me like there are two issues.  One, to make the
> behavior consistent with NT's, perhaps only flush the stream.

Making it consistent with what seems bad behaviour might be
regressive.

> But then, what if somebody _really_ wanted a sync done when
> SMB says to do one?  Is that two options?

Like maybe: fsync_Seriously(f); :-)

> Jim

Brett