On Tue, 2023-12-05 at 12:14 +0100, Christian Brauner wrote: > On Mon, Dec 04, 2023 at 03:09:44PM -0700, Jens Axboe wrote: > > On 12/4/23 2:02 PM, NeilBrown wrote: > > > It isn't clear to me what _GPL is appropriate, but maybe the rules > > > changed since last I looked..... are there rules? > > > > > > My reasoning was that the call is effectively part of the user-space > > > ABI. A user-space process can call this trivially by invoking any > > > system call. The user-space ABI is explicitly a boundary which the GPL > > > does not cross. So it doesn't seem appropriate to prevent non-GPL > > > kernel code from doing something that non-GPL user-space code can > > > trivially do. > > > > By that reasoning, basically everything in the kernel should be non-GPL > > marked. And while task_work can get used by the application, it happens > > only indirectly or implicitly. So I don't think this reasoning is sound > > at all, it's not an exported ABI or API by itself. > > > > For me, the more core of an export it is, the stronger the reason it > > should be GPL. FWIW, I don't think exporting task_work functionality is > > a good idea in the first place, but if there's a strong reason to do so, > > Yeah, I'm not too fond of that part as well. I don't think we want to > give modules the ability to mess with task work. This is just asking for > trouble. The fact that nfsd has to queue all of the delayed fput activity to a workqueue has always been a horrible hack though. We export all kinds of functionality to modules that you can screw up. I think that nfsd's use-case is legitimate. ksmbd may also want to follow suit. -- Jeff Layton <jlayton@xxxxxxxxxx>
