On Thu, Apr 23, 2020 at 09:45:45AM +0200, Miklos Szeredi wrote: > On Thu, Apr 23, 2020 at 9:33 AM Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote: > > > What are the plans for those syscalls that don't easily lend > > > themselves to this modification (such as accept(2))? > > > > accept4 has a flags argument with more flags available, so it'd be > > entirely possible to cleanly extend it further without introducing a new > > version. > > Variable argument syscalls, you are thinking? That or repurposing an existing pointer-sized argument as an open_how-style struct, yes. But in any case, I'm not proposing that; I'm proposing changes to the existing highly extensible openat2 syscall. > > > I mean, you could open the file descriptor outside of io_uring in such > > > cases, no? > > > > I would prefer to not introduce that limitation in the first place, and > > instead open normal file descriptors. > > > > > The point of O_SPECIFIC_FD is to be able to perform short > > > sequences of open/dosomething/close without having to block and having > > > to issue separate syscalls. > > > > "close" is not a required component. It's entirely possible to use > > io_uring to open a file descriptor, do various things with it, and then > > leave it open for subsequent usage via either other io_uring chains or > > standalone syscalls. > > If this use case arraises, This wasn't a hypothetical "someone might want this". I'm stating that this is a requirement I'm seeking to meet with this patch series, and one I intend to use. The primary use case is interoperability with other code using file descriptors and not using io_uring.