Re: [PATCH 01/13] blk-mq: avoid sleep in blk_mq_alloc_request_hctx

[Christoph Hellwig]

On Fri, Dec 23, 2022 at 08:52:11PM +0800, Kemeng Shi wrote:
> +	if (WARN_ON_ONCE(((!flags) & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED))))

This check does not make any sense.  I think what you want is

	if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT) ||
	    WARN_ON_ONCE(!(flags & BLK_MQ_REQ_RESERVED))))