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 8d613652d0e2f518929b395fb7aebe2e73176b77..98da5f5d847d23e3b1e0ed1f9100890d72239cb9 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4442,7 +4442,6 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
        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;