From fafcde3ac1a418688a734365203a12483b83907a Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sat, 12 Mar 2016 09:29:40 +0800 Subject: [PATCH] md: multipath: don't hardcopy bio in .make_request path Inside multipath_make_request(), multipath maps the incoming bio into low level device's bio, but it is totally wrong to copy the bio into mapped bio via '*mapped_bio = *bio'. For example, .__bi_remaining is kept in the copy, especially if the incoming bio is chained to via bio splitting, so .bi_end_io can't be called for the mapped bio at all in the completing path in this kind of situation. This patch fixes the issue by using clone style. Cc: stable@vger.kernel.org (v3.14+) Reported-and-tested-by: Andrea Righi Signed-off-by: Ming Lei Signed-off-by: Shaohua Li --- drivers/md/multipath.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c index 0a72ab6e6c20..dd483bb2e111 100644 --- a/drivers/md/multipath.c +++ b/drivers/md/multipath.c @@ -129,7 +129,9 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio) } multipath = conf->multipaths + mp_bh->path; - mp_bh->bio = *bio; + bio_init(&mp_bh->bio); + __bio_clone_fast(&mp_bh->bio, bio); + mp_bh->bio.bi_iter.bi_sector += multipath->rdev->data_offset; mp_bh->bio.bi_bdev = multipath->rdev->bdev; mp_bh->bio.bi_rw |= REQ_FAILFAST_TRANSPORT;