Re: [PATCH v2 09/13] md: raid1: use bio_segments_all()
From: Shaohua Li <shli@kernel.org>
Date: 2017-02-28 23:48:22
Also in:
linux-block
On Tue, Feb 28, 2017 at 11:41:39PM +0800, Ming Lei wrote:
Use this helper, instead of direct access to .bi_vcnt.
what We really need to do for the behind IO is: - allocate memory and copy bio data to the memory - let behind bio do IO against the memory The behind bio doesn't need to have the exactly same bio_vec setting. If we just track the new memory, we don't need use the bio_segments_all and access bio_vec too. Thanks, Shaohua
quoted hunk ↗ jump to hunk
Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- drivers/md/raid1.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 316bd6dd6cc1..7396c99ff7b1 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c@@ -1091,7 +1091,8 @@ static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio) { int i; struct bio_vec *bvec; - struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec), + unsigned vcnt = bio_segments_all(bio); + struct bio_vec *bvecs = kzalloc(vcnt * sizeof(struct bio_vec), GFP_NOIO); if (unlikely(!bvecs)) return;@@ -1107,12 +1108,12 @@ static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio) kunmap(bvec->bv_page); } r1_bio->behind_bvecs = bvecs; - r1_bio->behind_page_count = bio->bi_vcnt; + r1_bio->behind_page_count = vcnt; set_bit(R1BIO_BehindIO, &r1_bio->state); return; do_sync_io: - for (i = 0; i < bio->bi_vcnt; i++) + for (i = 0; i < vcnt; i++) if (bvecs[i].bv_page) put_page(bvecs[i].bv_page); kfree(bvecs);-- 2.7.4