On Thu, Jun 18, 2009 at 08:55:37AM +0200, Miklos Szeredi wrote: > Implement a new open flag that doesn't require any access on the file. > It works on any file type including symlinks. > > The sole purpose is to help race free "userspace lookup" type > operations. So fstat, fch*, *at work but nothing else. Filesystem's > ->open() is not called and f_op is set to NULL. we guarantee that f_op is never NULL, so you'll need to assign a file operations structure that is empty to it to avoid crashed in various places. > It would be logical to reuse the open_flag=3 value, but that has > historically been used with different semantics so I'm afraid of > touching it. I think the historical semantics are exactly that you can open it an issue ioctls + stat / etc on it ut not actually read/write it. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
