From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f197.google.com (mail-qk1-f197.google.com [209.85.222.197]) by kanga.kvack.org (Postfix) with ESMTP id C19088E0025 for ; Mon, 21 Jan 2019 03:21:24 -0500 (EST) Received: by mail-qk1-f197.google.com with SMTP id c84so18685192qkb.13 for ; Mon, 21 Jan 2019 00:21:24 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id j6si4028533qkk.237.2019.01.21.00.21.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 Jan 2019 00:21:24 -0800 (PST) From: Ming Lei Subject: [PATCH V14 12/18] bcache: avoid to use bio_for_each_segment_all() in bch_bio_alloc_pages() Date: Mon, 21 Jan 2019 16:17:59 +0800 Message-Id: <20190121081805.32727-13-ming.lei@redhat.com> In-Reply-To: <20190121081805.32727-1-ming.lei@redhat.com> References: <20190121081805.32727-1-ming.lei@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Theodore Ts'o , Omar Sandoval , Sagi Grimberg , Dave Chinner , Kent Overstreet , Mike Snitzer , dm-devel@redhat.com, Alexander Viro , linux-fsdevel@vger.kernel.org, linux-raid@vger.kernel.org, David Sterba , linux-btrfs@vger.kernel.org, "Darrick J . Wong" , linux-xfs@vger.kernel.org, Gao Xiang , Christoph Hellwig , linux-ext4@vger.kernel.org, Coly Li , linux-bcache@vger.kernel.org, Boaz Harrosh , Bob Peterson , cluster-devel@redhat.com, Ming Lei bch_bio_alloc_pages() is always called on one new bio, so it is safe to access the bvec table directly. Given it is the only kind of this case, open code the bvec table access since bio_for_each_segment_all() will be changed to support for iterating over multipage bvec. Acked-by: Coly Li Reviewed-by: Omar Sandoval Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei --- drivers/md/bcache/util.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c index 20eddeac1531..62fb917f7a4f 100644 --- a/drivers/md/bcache/util.c +++ b/drivers/md/bcache/util.c @@ -270,7 +270,11 @@ int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) int i; struct bio_vec *bv; - bio_for_each_segment_all(bv, bio, i) { + /* + * This is called on freshly new bio, so it is safe to access the + * bvec table directly. + */ + for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++, i++) { bv->bv_page = alloc_page(gfp_mask); if (!bv->bv_page) { while (--bv >= bio->bi_io_vec) -- 2.9.5