From: Xiao Ni <xni@redhat.com>
Date: Fri, 8 Mar 2019 15:52:05 +0000 (+0800)
Subject: It's wrong to add len to sector_nr in raid10 reshape twice
X-Git-Tag: v4.20.17~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=41ded4f889a9e4e2cd04b5f7263501e3ec308bcb;p=thirdparty%2Fkernel%2Fstable.git

It's wrong to add len to sector_nr in raid10 reshape twice

commit b761dcf1217760a42f7897c31dcb649f59b2333e upstream.

In reshape_request it already adds len to sector_nr already. It's wrong to add len to
sector_nr again after adding pages to bio. If there is bad block it can't copy one chunk
at a time, it needs to goto read_more. Now the sector_nr is wrong. It can cause data
corruption.

Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 12cf8a04e839b..100895695471b 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4692,7 +4692,6 @@ read_more:
 	atomic_inc(&r10_bio->remaining);
 	read_bio->bi_next = NULL;
 	generic_make_request(read_bio);
-	sector_nr += nr_sectors;
 	sectors_done += nr_sectors;
 	if (sector_nr <= last)
 		goto read_more;