Hi, On Tue, Jul 17, 2012 at 08:11:13AM +0000, Markus Pfeiffer wrote: > > while porting drivers from FreeBSD some of us have stumbled over the functions > devfs_get_cdevpriv and devfs_set_cdevpriv, which store some > per-open-filedescriptor information for some devices. > > I looked into the FreeBSD code and the implementation seems weird to me since > they store the filedescriptor on syscall in their thread struct and the > functions > rely on that hidden state. > > Question is now: Should we have similar functionality (i.e. per open > filedescriptor "private" data) and if yes how to best implement that. I know > that AlexH had made some suggestion but I cannot find it in the IRC logs and > it would probably be more efficient doing this by mail.
I encountered the same family of functions while looking at recent FreeBSD DRM code; since it was ported from Linux in the first place, I also looked at the Linux equivalent functions, and they seemed much more sane. Private data was directly accessible from the filedescriptor if I remember correctly. -- Francois Tigeot
