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 <tom.leim...@gmail.com> --- 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