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: Nmajianpeng <majianpeng@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

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;

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)