From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Lei Subject: [PATCH v1 2/5] md/raid1: use bio_clone_bioset_partial() in case of write behind Date: Fri, 10 Feb 2017 18:56:14 +0800 Message-ID: <1486724177-14817-3-git-send-email-tom.leiming@gmail.com> References: <1486724177-14817-1-git-send-email-tom.leiming@gmail.com> Return-path: In-Reply-To: <1486724177-14817-1-git-send-email-tom.leiming@gmail.com> Sender: linux-block-owner@vger.kernel.org To: Shaohua Li , Jens Axboe , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig , NeilBrown Cc: Ming Lei List-Id: linux-raid.ids Write behind need to replace pages in bio's bvecs, and we have to clone a fresh bio with new bvec table, so use the introduced bio_clone_bioset_partial() for it. For other bio_clone_mddev() cases, we will use fast clone since they don't need to touch bvec table. Signed-off-by: Ming Lei --- drivers/md/raid1.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 830ff2b20346..4d7852c6ae97 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1341,13 +1341,12 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, first_clone = 1; for (i = 0; i < disks; i++) { - struct bio *mbio; + struct bio *mbio = NULL; + int offset; if (!r1_bio->bios[i]) continue; - mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); - bio_trim(mbio, r1_bio->sector - bio->bi_iter.bi_sector, - max_sectors); + offset = r1_bio->sector - bio->bi_iter.bi_sector; if (first_clone) { /* do behind I/O ? @@ -1357,8 +1356,13 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, if (bitmap && (atomic_read(&bitmap->behind_writes) < mddev->bitmap_info.max_write_behind) && - !waitqueue_active(&bitmap->behind_wait)) + !waitqueue_active(&bitmap->behind_wait)) { + mbio = bio_clone_bioset_partial(bio, GFP_NOIO, + mddev->bio_set, + offset, + max_sectors); alloc_behind_pages(mbio, r1_bio); + } bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors, @@ -1366,6 +1370,12 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, &r1_bio->state)); first_clone = 0; } + + if (!mbio) { + mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); + bio_trim(mbio, offset, max_sectors); + } + if (r1_bio->behind_bvecs) { struct bio_vec *bvec; int j; -- 2.7.4