Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752646AbdF0QXY (ORCPT ); Tue, 27 Jun 2017 12:23:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60052 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752249AbdF0QXO (ORCPT ); Tue, 27 Jun 2017 12:23:14 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 469797F3FE Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=ming.lei@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 469797F3FE Date: Wed, 28 Jun 2017 00:22:51 +0800 From: Ming Lei To: Guoqing Jiang Cc: Jens Axboe , Christoph Hellwig , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Shaohua Li , linux-raid@vger.kernel.org Subject: Re: [PATCH v2 11/51] md: raid1: initialize bvec table via bio_add_page() Message-ID: <20170627162242.GA19610@ming.t460p> References: <20170626121034.3051-1-ming.lei@redhat.com> <20170626121034.3051-12-ming.lei@redhat.com> <59522727.7040700@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <59522727.7040700@suse.com> User-Agent: Mutt/1.8.0 (2017-02-23) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 27 Jun 2017 16:23:13 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5944 Lines: 180 On Tue, Jun 27, 2017 at 05:36:39PM +0800, Guoqing Jiang wrote: > > > On 06/26/2017 08:09 PM, Ming Lei wrote: > > We will support multipage bvec soon, so initialize bvec > > table using the standardy way instead of writing the > > talbe directly. Otherwise it won't work any more once > > multipage bvec is enabled. > > > > Cc: Shaohua Li > > Cc: linux-raid@vger.kernel.org > > Signed-off-by: Ming Lei > > --- > > drivers/md/raid1.c | 27 ++++++++++++++------------- > > 1 file changed, 14 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c > > index 3febfc8391fb..835c42396861 100644 > > --- a/drivers/md/raid1.c > > +++ b/drivers/md/raid1.c > > @@ -2086,10 +2086,8 @@ static void process_checks(struct r1bio *r1_bio) > > /* Fix variable parts of all bios */ > > vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); > > for (i = 0; i < conf->raid_disks * 2; i++) { > > - int j; > > int size; > > blk_status_t status; > > - struct bio_vec *bi; > > struct bio *b = r1_bio->bios[i]; > > struct resync_pages *rp = get_resync_pages(b); > > if (b->bi_end_io != end_sync_read) > > @@ -2098,8 +2096,6 @@ static void process_checks(struct r1bio *r1_bio) > > status = b->bi_status; > > bio_reset(b); > > b->bi_status = status; > > - b->bi_vcnt = vcnt; > > - b->bi_iter.bi_size = r1_bio->sectors << 9; > > b->bi_iter.bi_sector = r1_bio->sector + > > conf->mirrors[i].rdev->data_offset; > > b->bi_bdev = conf->mirrors[i].rdev->bdev; > > @@ -2107,15 +2103,20 @@ static void process_checks(struct r1bio *r1_bio) > > rp->raid_bio = r1_bio; > > b->bi_private = rp; > > - size = b->bi_iter.bi_size; > > - bio_for_each_segment_all(bi, b, j) { > > - bi->bv_offset = 0; > > - if (size > PAGE_SIZE) > > - bi->bv_len = PAGE_SIZE; > > - else > > - bi->bv_len = size; > > - size -= PAGE_SIZE; > > - } > > + /* initialize bvec table again */ > > + rp->idx = 0; > > + size = r1_bio->sectors << 9; > > + do { > > + struct page *page = resync_fetch_page(rp, rp->idx++); > > + int len = min_t(int, size, PAGE_SIZE); > > + > > + /* > > + * won't fail because the vec table is big > > + * enough to hold all these pages > > + */ > > + bio_add_page(b, page, len, 0); > > + size -= len; > > + } while (rp->idx < RESYNC_PAGES && size > 0); > > } > > Seems above section is similar as reset_bvec_table introduced in next patch, > why there is difference between raid1 and raid10? Maybe add reset_bvec_table > into md.c, then call it in raid1 or raid10 is better, just my 2 cents. Hi Guoqing, I think it is a good idea, and even the two patches can be put into one, so how about the following patch? Shaohua, what do you think of this one? --- diff --git a/drivers/md/md.c b/drivers/md/md.c index 3d957ac1e109..7ffc622dd7fa 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -9126,6 +9126,24 @@ void md_reload_sb(struct mddev *mddev, int nr) } EXPORT_SYMBOL(md_reload_sb); +/* generally called after bio_reset() for reseting bvec */ +void reset_bvec_table(struct bio *bio, struct resync_pages *rp, int size) +{ + /* initialize bvec table again */ + rp->idx = 0; + do { + struct page *page = resync_fetch_page(rp, rp->idx++); + int len = min_t(int, size, PAGE_SIZE); + + /* + * won't fail because the vec table is big + * enough to hold all these pages + */ + bio_add_page(bio, page, len, 0); + size -= len; + } while (rp->idx < RESYNC_PAGES && size > 0); +} + #ifndef MODULE /* diff --git a/drivers/md/md.h b/drivers/md/md.h index 991f0fe2dcc6..f569831b1de9 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -783,4 +783,6 @@ static inline struct page *resync_fetch_page(struct resync_pages *rp, return NULL; return rp->pages[idx]; } + +void reset_bvec_table(struct bio *bio, struct resync_pages *rp, int size); #endif /* _MD_MD_H */ diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 3febfc8391fb..6ae2665ecd58 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -2086,10 +2086,7 @@ static void process_checks(struct r1bio *r1_bio) /* Fix variable parts of all bios */ vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); for (i = 0; i < conf->raid_disks * 2; i++) { - int j; - int size; blk_status_t status; - struct bio_vec *bi; struct bio *b = r1_bio->bios[i]; struct resync_pages *rp = get_resync_pages(b); if (b->bi_end_io != end_sync_read) @@ -2098,8 +2095,6 @@ static void process_checks(struct r1bio *r1_bio) status = b->bi_status; bio_reset(b); b->bi_status = status; - b->bi_vcnt = vcnt; - b->bi_iter.bi_size = r1_bio->sectors << 9; b->bi_iter.bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; b->bi_bdev = conf->mirrors[i].rdev->bdev; @@ -2107,15 +2102,8 @@ static void process_checks(struct r1bio *r1_bio) rp->raid_bio = r1_bio; b->bi_private = rp; - size = b->bi_iter.bi_size; - bio_for_each_segment_all(bi, b, j) { - bi->bv_offset = 0; - if (size > PAGE_SIZE) - bi->bv_len = PAGE_SIZE; - else - bi->bv_len = size; - size -= PAGE_SIZE; - } + /* initialize bvec table again */ + reset_bvec_table(b, rp, r1_bio->sectors << 9); } for (primary = 0; primary < conf->raid_disks * 2; primary++) if (r1_bio->bios[primary]->bi_end_io == end_sync_read && diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 5026e7ad51d3..72f4fa07449b 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -2087,8 +2087,8 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio) rp = get_resync_pages(tbio); bio_reset(tbio); - tbio->bi_vcnt = vcnt; - tbio->bi_iter.bi_size = fbio->bi_iter.bi_size; + reset_bvec_table(tbio, rp, fbio->bi_iter.bi_size); + rp->raid_bio = r10_bio; tbio->bi_private = rp; tbio->bi_iter.bi_sector = r10_bio->devs[i].addr; Thanks, Ming