Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753522Ab0FWPLL (ORCPT ); Wed, 23 Jun 2010 11:11:11 -0400 Received: from sh.osrg.net ([192.16.179.4]:39444 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753194Ab0FWPLJ (ORCPT ); Wed, 23 Jun 2010 11:11:09 -0400 From: FUJITA Tomonori To: axboe@kernel.dk, James.Bottomley@HansenPartnership.com Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, fujita.tomonori@lab.ntt.co.jp Subject: [PATCH 2/3] block: introduce REQ_FLUSH flag Date: Thu, 24 Jun 2010 00:07:31 +0900 Message-Id: <1277305652-2306-3-git-send-email-fujita.tomonori@lab.ntt.co.jp> X-Mailer: git-send-email 1.6.5 In-Reply-To: <1277305652-2306-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> References: <1277305652-2306-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (sh.osrg.net [192.16.179.4]); Thu, 24 Jun 2010 00:10:58 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2132 Lines: 54 SCSI-ml needs a way to mark a request as flush request in q->prepare_flush_fn because it needs to identify them later (e.g. in q->request_fn or prep_rq_fn). queue_flush sets REQ_HARDBARRIER in rq->cmd_flags however the block layer also sends normal REQ_TYPE_FS requests with REQ_HARDBARRIER. So SCSI-ml can't use REQ_HARDBARRIER to identify flush requests. We could change the block layer to clear REQ_HARDBARRIER bit before sending non flush requests to the lower layers. However, intorudcing the new flag looks cleaner (surely easier). Signed-off-by: FUJITA Tomonori --- block/blk-barrier.c | 2 +- include/linux/bio.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletions(-) diff --git a/block/blk-barrier.c b/block/blk-barrier.c index 4646f6d..ce4e9b8 100644 --- a/block/blk-barrier.c +++ b/block/blk-barrier.c @@ -143,7 +143,7 @@ static void queue_flush(struct request_queue *q, unsigned which) } blk_rq_init(q, rq); - rq->cmd_flags = REQ_HARDBARRIER; + rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH; rq->rq_disk = q->orig_bar_rq->rq_disk; rq->end_io = end_io; q->prepare_flush_fn(q, rq); diff --git a/include/linux/bio.h b/include/linux/bio.h index 4d379c8..331bd0a 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -152,6 +152,7 @@ enum rq_flag_bits { __REQ_SYNC, /* request is sync (sync write or read) */ __REQ_META, /* metadata io request */ __REQ_DISCARD, /* request to discard sectors */ + __REQ_FLUSH, /* request for cache flush */ __REQ_NOIDLE, /* don't anticipate more IO after this one */ /* bio only flags */ @@ -187,6 +188,7 @@ enum rq_flag_bits { #define REQ_SYNC (1 << __REQ_SYNC) #define REQ_META (1 << __REQ_META) #define REQ_DISCARD (1 << __REQ_DISCARD) +#define REQ_FLUSH (1 << __REQ_FLUSH) #define REQ_NOIDLE (1 << __REQ_NOIDLE) #define REQ_FAILFAST_MASK \ -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/