On Fri, Apr 11, 2008 at 09:12:23PM +0200, Miklos Szeredi wrote: > > > OK. So the correct fix here should really be applied to fcntl_setlk(). > > > There is absolutely no reason why we should be looping at all if the > > > filesystem has a ->lock() method. > > > > > > In fact, this looping behaviour was introduced recently in commit > > > 7723ec9777d9832849b76475b1a21a2872a40d20. > > > > Apologies, that was indeed a behavioral change introduced in a commit > > that claimed just to be shuffling code around. > > Yeah, that patch looks totally wrong. It's not generally a good idea > to do a loop where the exit condition depends on something you don't > control. And error values from filesystem methods are typically like > that. For example with fuse, the error code could come from an > unprivileged userspace process. > > I didn't realize this aspect of the bug previously, because I > concentrated on the lockd inconsistency. > > Btw, why hasn't this work been posted on -fsdevel prior to merging > into mainline? http://marc.info/?l=linux-fsdevel&m=117581629326194&w=2 --b. > > > > > > Marc, Bruce, why was this > > > done, and how are filesystems now supposed to behave? > > > > > > > The assumption must have been that -EAGAIN could only mean that we > > needed to keep blocking, and hence was a nonsensical return from a > > filesystem lock method that waited itself for the lock to become > > available--such a method would return 0, -EINTR (or some more exotic > > error), or continue waiting. > > EAGAIN for a blocking lock is nonsensical, so my original patch could > still make sense. But that's no longer a regression, and not all that > important. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
