Re: [PATCH 1/1] io_uring: more graceful request alloc OOM

[Pavel Begunkov <asml.silence@gmail.com>]

On 5/20/23 10:38, yang lan wrote:
> Hi,
> 
> Thanks for your response.
> 
> But I applied this patch to LTS kernel 5.10.180, it can still trigger this bug.
> 
> --- io_uring/io_uring.c.back    2023-05-20 17:11:25.870550438 +0800
> +++ io_uring/io_uring.c 2023-05-20 16:35:24.265846283 +0800
> @@ -1970,7 +1970,7 @@
> static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
>          __must_hold(&ctx->uring_lock)
>   {
>          struct io_submit_state *state = &ctx->submit_state;
> -       gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
> +       gfp_t gfp = GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY;
>          int ret, i;
> 
>          BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH);
> 
> The io_uring.c.back is the original file.
> Do I apply this patch wrong?

The patch looks fine. I run a self-written test before
sending with 6.4, worked as expected. I need to run the syz
test, maybe it shifted to another spot, e.g. in provided
buffers.

-- 
Pavel Begunkov