Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754916Ab0GCIrJ (ORCPT ); Sat, 3 Jul 2010 04:47:09 -0400 Received: from sh.osrg.net ([192.16.179.4]:47326 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751751Ab0GCIrE (ORCPT ); Sat, 3 Jul 2010 04:47:04 -0400 From: FUJITA Tomonori To: axboe@kernel.dk Cc: hch@infradead.org, linux-kernel@vger.kernel.org, fujita.tomonori@lab.ntt.co.jp, James Bottomley , "David S. Miller" , Rusty Russell , Alasdair G Kergon Subject: [PATCH 1/9] block: introduce REQ_FLUSH flag Date: Sat, 3 Jul 2010 17:45:32 +0900 Message-Id: <1278146740-8731-2-git-send-email-fujita.tomonori@lab.ntt.co.jp> X-Mailer: git-send-email 1.6.5 In-Reply-To: <1278146740-8731-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> References: <1278146740-8731-1-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]); Sat, 03 Jul 2010 17:46:32 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2420 Lines: 58 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 Cc: James Bottomley Cc: David S. Miller Cc: Rusty Russell Cc: Alasdair G Kergon --- 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 7c6f4a7..a348242 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->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..f655b54 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -174,6 +174,7 @@ enum rq_flag_bits { __REQ_ALLOCED, /* request came from our alloc pool */ __REQ_COPY_USER, /* contains copies of user pages */ __REQ_INTEGRITY, /* integrity metadata has been remapped */ + __REQ_FLUSH, /* request for cache flush */ __REQ_IO_STAT, /* account I/O stat */ __REQ_MIXED_MERGE, /* merge of different types, fail separately */ __REQ_NR_BITS, /* stops here */ @@ -213,6 +214,7 @@ enum rq_flag_bits { #define REQ_ALLOCED (1 << __REQ_ALLOCED) #define REQ_COPY_USER (1 << __REQ_COPY_USER) #define REQ_INTEGRITY (1 << __REQ_INTEGRITY) +#define REQ_FLUSH (1 << __REQ_FLUSH) #define REQ_IO_STAT (1 << __REQ_IO_STAT) #define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE) -- 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/