From 41743c1f046a14c6749fd1808bb3793c08e47a3e Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Fri, 24 Mar 2017 15:20:47 -0700 Subject: [PATCH] md/raid1: skip data copy for behind io for discard request discard request doesn't have data attached, so it's meaningless to allocate memory and copy from original bio for behind IO. And the copy is bogus because bio_copy_data_partial can't handle discard request. We don't support writesame/writezeros request so far. Reviewed-by: Ming Lei Signed-off-by: Shaohua Li --- drivers/md/raid1.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index c6a671f13bc0..b7d9651286d4 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1102,6 +1102,10 @@ static struct bio *alloc_behind_master_bio(struct r1bio *r1_bio, if (!behind_bio) goto fail; + /* discard op, we don't support writezero/writesame yet */ + if (!bio_has_data(bio)) + goto skip_copy; + while (i < vcnt && size) { struct page *page; int len = min_t(int, PAGE_SIZE, size); @@ -1118,7 +1122,7 @@ static struct bio *alloc_behind_master_bio(struct r1bio *r1_bio, bio_copy_data_partial(behind_bio, bio, offset, behind_bio->bi_iter.bi_size); - +skip_copy: r1_bio->behind_master_bio = behind_bio;; set_bit(R1BIO_BehindIO, &r1_bio->state); -- 2.20.1