From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it1-f193.google.com ([209.85.166.193]:40677 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726451AbeLRPmj (ORCPT ); Tue, 18 Dec 2018 10:42:39 -0500 Received: by mail-it1-f193.google.com with SMTP id h193so4800343ita.5 for ; Tue, 18 Dec 2018 07:42:39 -0800 (PST) From: Jens Axboe To: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org Cc: hch@lst.de, viro@zeniv.linux.org.uk, Jens Axboe Subject: [PATCH 02/22] block: add REQ_HIPRI_ASYNC Date: Tue, 18 Dec 2018 08:42:10 -0700 Message-Id: <20181218154230.3120-3-axboe@kernel.dk> In-Reply-To: <20181218154230.3120-1-axboe@kernel.dk> References: <20181218154230.3120-1-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 fc99474ac968..4845250b5ba0 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -348,6 +348,7 @@ 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