Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754638AbcLaK3i (ORCPT ); Sat, 31 Dec 2016 05:29:38 -0500 Received: from mail-lf0-f65.google.com ([209.85.215.65]:36601 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751264AbcLaK3f (ORCPT ); Sat, 31 Dec 2016 05:29:35 -0500 MIME-Version: 1.0 In-Reply-To: <4d015585-c830-17ff-de4a-60f2d5f06a0d@coly.li> References: <1482854250-13481-1-git-send-email-tom.leiming@gmail.com> <1482854250-13481-24-git-send-email-tom.leiming@gmail.com> <4d015585-c830-17ff-de4a-60f2d5f06a0d@coly.li> From: Ming Lei Date: Sat, 31 Dec 2016 18:29:32 +0800 Message-ID: Subject: Re: [PATCH v1 23/54] bcache: handle bio_clone() & bvec updating for multipage bvecs To: Coly Li Cc: Jens Axboe , Linux Kernel Mailing List , linux-block , Christoph Hellwig , Kent Overstreet , Shaohua Li , Mike Christie , Guoqing Jiang , "open list:BCACHE (BLOCK LAYER CACHE)" , "open list:SOFTWARE RAID (Multiple Disks) SUPPORT" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id uBVATm5c019468 Content-Length: 2707 Lines: 89 Hi Coly, On Fri, Dec 30, 2016 at 7:01 PM, Coly Li wrote: > On 2016/12/27 下午11:56, Ming Lei wrote: >> The incoming bio may be too big to be cloned into >> one singlepage bvecs bio, so split the bio and >> check the splitted bio one by one. >> >> Signed-off-by: Ming Lei >> --- >> drivers/md/bcache/debug.c | 24 ++++++++++++++++++++++-- >> 1 file changed, 22 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c >> index 48d03e8b3385..18b2d2d138e3 100644 >> --- a/drivers/md/bcache/debug.c >> +++ b/drivers/md/bcache/debug.c >> @@ -103,7 +103,7 @@ void bch_btree_verify(struct btree *b) >> up(&b->io_mutex); >> } >> >> -void bch_data_verify(struct cached_dev *dc, struct bio *bio) >> +static void __bch_data_verify(struct cached_dev *dc, struct bio *bio) >> { >> char name[BDEVNAME_SIZE]; >> struct bio *check; >> @@ -116,7 +116,7 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio) >> * in the new cloned bio because each single page need >> * to assign to each bvec of the new bio. >> */ >> - check = bio_clone(bio, GFP_NOIO); >> + check = bio_clone_sp(bio, GFP_NOIO); >> if (!check) >> return; >> check->bi_opf = REQ_OP_READ; >> @@ -151,6 +151,26 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio) >> bio_put(check); >> } >> >> +void bch_data_verify(struct cached_dev *dc, struct bio *bio) >> +{ >> + struct request_queue *q = bdev_get_queue(bio->bi_bdev); >> + struct bio *clone = bio_clone_fast(bio, GFP_NOIO, q->bio_split); >> + unsigned sectors; >> + >> + while (!bio_can_convert_to_sp(clone, §ors)) { >> + struct bio *split = bio_split(clone, sectors, >> + GFP_NOIO, q->bio_split); >> + >> + __bch_data_verify(dc, split); >> + bio_put(split); >> + } >> + >> + if (bio_sectors(clone)) >> + __bch_data_verify(dc, clone); >> + >> + bio_put(clone); >> +} >> + > > Hi Lei, > > The above patch is good IMHO. Just wondering why not use the classical > style ? something like, I don't know there is the classical style, :-) > > > do { > if (!bio_can_convert_to_sp(clone, §ors)) > split = bio_split(clone, sectors, > GFP_NOIO, q->bio_split); > else > split = clone; > > __bch_data_verity(gc, split); > bio_put(split); > } while (split != clone); > > > I guess maybe the above style generates less binary code. Maybe, will take this style in V2. Thanks for the review! -- Ming Lei