Jens Axboe <axboe@xxxxxxxxx> writes: > On 10/4/19 9:34 AM, Jeff Moyer wrote: >> If I'm reading this (and the code) right, that means you can't add files >> to a set. Wouldn't that be a useful thing to do, instead of just >> replacing existing ones? > > You can add files to a set, you just can't grow a set beyond the size > you originally registered. I actually forgot to post the pre-patch for > this, which is: > > http://git.kernel.dk/cgit/linux-block/commit/?h=for-5.5/io_uring&id=fb3e60f87aa43f4f047f01243d6be54dadd9d67a > > This allows registering -1 as the fd, so you could register 10 files, > but an array of size 500 (for example), and the last 490 fds are just > -1. Then you can use the IORING_REGISTER_FILES_UPDATE to replace those > empty fds with real files later on. That makes more sense, but still requires a priori knowledge of how many files you'll need to work with, otherwise you're back to unregister/register dance. Is it really that hard to grow on demand? >> Can you post the man page update along with this? > > Yes, I'll write the documentation too, just wanted consensus on the > approach before I wrote up documentation. Gotcha. -Jeff
