From: Tejun Heo Subject: [PATCH 1/3] block: add REQ_FLUSH_SEQ Date: Fri, 21 Jan 2011 16:59:56 +0100 Message-ID: <1295625598-15203-2-git-send-email-tj@kernel.org> References: <1295625598-15203-1-git-send-email-tj@kernel.org> Cc: Tejun Heo To: axboe@kernel.dk, tytso@mit.edu, djwong@us.ibm.com, shli@kernel.org, neilb@suse.de, adilger.kernel@dilger.ca, jack@suse.cz, snitzer@redhat.com, linux-kernel@vger.kernel.org, kmannth@us Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:60611 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752733Ab1AUQAT (ORCPT ); Fri, 21 Jan 2011 11:00:19 -0500 In-Reply-To: <1295625598-15203-1-git-send-email-tj@kernel.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: rq == &q->flush_rq was used to determine whether a rq is part of a flush sequence, which worked because all requests in a flush sequence were sequenced using the single dedicated request. This is about to change, so introduce REQ_FLUSH_SEQ flag to distinguish flush sequence requests. This patch doesn't cause any behavior change. Signed-off-by: Tejun Heo --- block/blk-core.c | 4 ++-- block/blk-flush.c | 1 + block/blk.h | 2 +- include/linux/blk_types.h | 2 ++ 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 2f4002f..22e0b4f 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -151,7 +151,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio, { struct request_queue *q = rq->q; - if (&q->flush_rq != rq) { + if (!(rq->cmd_flags & REQ_FLUSH_SEQ)) { if (error) clear_bit(BIO_UPTODATE, &bio->bi_flags); else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) @@ -1804,7 +1804,7 @@ static void blk_account_io_done(struct request *req) * normal IO on queueing nor completion. Accounting the * containing request is enough. */ - if (blk_do_io_stat(req) && req != &req->q->flush_rq) { + if (blk_do_io_stat(req) && !(req->cmd_flags & REQ_FLUSH_SEQ)) { unsigned long duration = jiffies - req->start_time; const int rw = rq_data_dir(req); struct hd_struct *part; diff --git a/block/blk-flush.c b/block/blk-flush.c index 54b123d..8592869 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -130,6 +130,7 @@ static struct request *queue_next_fseq(struct request_queue *q) BUG(); } + rq->cmd_flags |= REQ_FLUSH_SEQ; elv_insert(q, rq, ELEVATOR_INSERT_FRONT); return rq; } diff --git a/block/blk.h b/block/blk.h index 2db8f32..9d2ee8f 100644 --- a/block/blk.h +++ b/block/blk.h @@ -61,7 +61,7 @@ static inline struct request *__elv_next_request(struct request_queue *q) while (!list_empty(&q->queue_head)) { rq = list_entry_rq(q->queue_head.next); if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) || - rq == &q->flush_rq) + (rq->cmd_flags & REQ_FLUSH_SEQ)) return rq; rq = blk_do_flush(q, rq); if (rq) diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 46ad519..dddedfc 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -148,6 +148,7 @@ enum rq_flag_bits { __REQ_ALLOCED, /* request came from our alloc pool */ __REQ_COPY_USER, /* contains copies of user pages */ __REQ_FLUSH, /* request for cache flush */ + __REQ_FLUSH_SEQ, /* request for flush sequence */ __REQ_IO_STAT, /* account I/O stat */ __REQ_MIXED_MERGE, /* merge of different types, fail separately */ __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ @@ -188,6 +189,7 @@ enum rq_flag_bits { #define REQ_ALLOCED (1 << __REQ_ALLOCED) #define REQ_COPY_USER (1 << __REQ_COPY_USER) #define REQ_FLUSH (1 << __REQ_FLUSH) +#define REQ_FLUSH_SEQ (1 << __REQ_FLUSH_SEQ) #define REQ_IO_STAT (1 << __REQ_IO_STAT) #define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE) #define REQ_SECURE (1 << __REQ_SECURE) -- 1.7.1