From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it1-f195.google.com ([209.85.166.195]:34288 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729348AbeLMR44 (ORCPT ); Thu, 13 Dec 2018 12:56:56 -0500 Received: by mail-it1-f195.google.com with SMTP id x124so16910406itd.1 for ; Thu, 13 Dec 2018 09:56:56 -0800 (PST) From: Jens Axboe To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org Cc: hch@lst.de, jmoyer@redhat.com, clm@fb.com, Jens Axboe Subject: [PATCH 02/26] block: add REQ_HIPRI_ASYNC Date: Thu, 13 Dec 2018 10:56:21 -0700 Message-Id: <20181213175645.22181-3-axboe@kernel.dk> In-Reply-To: <20181213175645.22181-1-axboe@kernel.dk> References: <20181213175645.22181-1-axboe@kernel.dk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: For the upcoming async polled IO, we can't sleep allocating requests. If we do, then we introduce a deadlock where the submitter already has async polled IO in-flight, but can't wait for them to complete since polled requests must be active found and reaped. Signed-off-by: Jens Axboe --- include/linux/blk_types.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 46c005d601ac..921d734d6b5d 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -347,6 +347,7 @@ enum req_flag_bits { #define REQ_NOWAIT (1ULL << __REQ_NOWAIT) #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP) #define REQ_HIPRI (1ULL << __REQ_HIPRI) +#define REQ_HIPRI_ASYNC (REQ_HIPRI | REQ_NOWAIT) #define REQ_DRV (1ULL << __REQ_DRV) #define REQ_SWAP (1ULL << __REQ_SWAP) -- 2.17.1