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, 2 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index fff782189e48..c8dbb84d5357 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1788,6 +1788,7 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
         struct r10conf *conf = mddev->private;
         int i, first;
         struct bio *tbio, *fbio;
+        int vcnt;
 
         atomic_set(&r10_bio->remaining, 1);
 
@@ -1802,10 +1803,10 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
         first = i;
         fbio = r10_bio->devs[i].bio;
 
+        vcnt = (r10_bio->sectors + (PAGE_SIZE >> 9) - 1) >> (PAGE_SHIFT - 9);
         /* now find blocks with errors */
         for (i=0 ; i < conf->copies ; i++) {
                 int  j, d;
-                int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
 
                 tbio = r10_bio->devs[i].bio;
 
@@ -1871,7 +1872,6 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
          */
         for (i = 0; i < conf->copies; i++) {
                 int j, d;
-                int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
 
                 tbio = r10_bio->devs[i].repl_bio;
                 if (!tbio || !tbio->bi_end_io)