md/raid1,raid10: Fix calculation of 'vcnt' when processing error recovery.

If r1bio->sectors % 8 != 0,then the memcmp and a later
memcpy will omit the last bio_vec.

This is suitable for any stable kernel since 3.1 when bad-block
management was introduced.

Cc: stable@vger.kernel.org
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d35e4c991e38..15dd59b84e94 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1712,6 +1712,7 @@ static int process_checks(struct r1bio *r1_bio)
         struct r1conf *conf = mddev->private;
         int primary;
         int i;
+        int vcnt;
 
         for (primary = 0; primary < conf->raid_disks * 2; primary++)
                 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
@@ -1721,9 +1722,9 @@ static int process_checks(struct r1bio *r1_bio)
                         break;
                 }
         r1_bio->read_disk = primary;
+        vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
         for (i = 0; i < conf->raid_disks * 2; i++) {
                 int j;
-                int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
                 struct bio *pbio = r1_bio->bios[primary];
                 struct bio *sbio = r1_bio->bios[i];
                 int size;