[ 12/75] md/raid1,raid10: Fix calculation of vcnt when processing error recovery.

[Greg KH]

3.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: majianpeng <majianpeng@xxxxxxxxx>

commit f4380a915823dbed0bf8e3cf502ebcf2b7c7f833 upstream.

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.

Signed-off-by: majianpeng <majianpeng@xxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/md/raid1.c  |    3 ++-
 drivers/md/raid10.c |    4 ++--
 2 files changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1669,6 +1669,7 @@ static int process_checks(struct r1bio *
 	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 &&
@@ -1678,9 +1679,9 @@ static int process_checks(struct r1bio *
 			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;
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1742,6 +1742,7 @@ static void sync_request_write(struct md
 	struct r10conf *conf = mddev->private;
 	int i, first;
 	struct bio *tbio, *fbio;
+	int vcnt;
 
 	atomic_set(&r10_bio->remaining, 1);
 
@@ -1756,10 +1757,10 @@ static void sync_request_write(struct md
 	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;
 
@@ -1825,7 +1826,6 @@ static void sync_request_write(struct md
 	 */
 	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)


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