Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759432AbcDBBUL (ORCPT ); Fri, 1 Apr 2016 21:20:11 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54272 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757038AbcDBA4O (ORCPT ); Fri, 1 Apr 2016 20:56:14 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Ming Lei , Shaohua Li , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 092/170] md: multipath: don't hardcopy bio in .make_request path Date: Fri, 1 Apr 2016 17:52:58 -0700 Message-Id: <1459558456-24452-93-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1459558456-24452-1-git-send-email-kamal@canonical.com> References: <1459558456-24452-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1536 Lines: 43 3.19.8-ckt18 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Ming Lei 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 Signed-off-by: Ming Lei Signed-off-by: Shaohua Li Signed-off-by: Kamal Mostafa --- 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 399272f..2df218d 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; -- 2.7.4