Messages in this thread Patch in this message | | | Date | Mon, 26 Sep 2022 20:12:57 +0100 | Subject | Re: [PATCH v2 1/3] io_uring: register single issuer task at creation | From | Pavel Begunkov <> |
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On 9/26/22 18:09, Dylan Yudaken wrote: > Instead of picking the task from the first submitter task, rather use the > creator task or in the case of disabled (IORING_SETUP_R_DISABLED) the > enabling task. > > This approach allows a lot of simplification of the logic here. This > removes init logic from the submission path, which can always be a bit > confusing, but also removes the need for locking to write (or read) the > submitter_task. > > Users that want to move a ring before submitting can create the ring > disabled and then enable it on the submitting task.
I think Dylan briefly mentioned before that it might be a good idea to task limit registration as well. I can't think of a use case at the moment but I agree we may find some in the future.
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 242d896c00f3..60a471e43fd9 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3706,6 +3706,9 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs))) return -ENXIO; + if (ctx->submitter_task && ctx->submitter_task != current) + return -EEXIST; + if (ctx->restricted) { if (opcode >= IORING_REGISTER_LAST) return -EINVAL;
-- Pavel Begunkov
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