Re: [PATCH for-next] io_uring: ensure overflow entries are dropped when ring is exiting

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

On 4/12/24 20:18, Jens Axboe wrote:
> A previous consolidation cleanup missed handling the case where the ring
> is dying, and __io_cqring_overflow_flush() doesn't flush entries if the
> CQ ring is already full. This is fine for the normal CQE overflow
> flushing, but if the ring is going away, we need to flush everything,
> even if it means simply freeing the overflown entries.

Indeed, sounds like a good idea to enable leak detection
for my testing.


> Fixes: 6c948ec44b29 ("io_uring: consolidate overflow flushing")
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> 
> ---
> 
> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
> index c4419eef7e63..3c9087f37c43 100644
> --- a/io_uring/io_uring.c
> +++ b/io_uring/io_uring.c
> @@ -674,7 +674,8 @@ static void __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool dying)
>   
>   	lockdep_assert_held(&ctx->uring_lock);
>   
> -	if (__io_cqring_events(ctx) == ctx->cq_entries)
> +	/* don't abort if we're dying, entries must get freed */
> +	if (!dying && __io_cqring_events(ctx) == ctx->cq_entries)
>   		return;
>   
>   	if (ctx->flags & IORING_SETUP_CQE32)
> 

-- 
Pavel Begunkov