| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.5 166/238] md: multipath: dont hardcopy bio in .make_request path | Date | Sun, 10 Apr 2016 11:35:43 -0700 |
| |
4.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ming Lei <ming.lei@canonical.com>
commit fafcde3ac1a418688a734365203a12483b83907a upstream.
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.
Reported-and-tested-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/multipath.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/md/multipath.c +++ b/drivers/md/multipath.c @@ -129,7 +129,9 @@ static void multipath_make_request(struc } 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;
|