md: fix two raid10 bugs
1/ When resyncing a degraded raid10 which has more than 2 copies of each block,
garbage can get synced on top of good data.
2/ We round the wrong way in part of the device size calculation, which
can cause confusion.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 82249a6..9eb66c1 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1867,6 +1867,7 @@
int d = r10_bio->devs[i].devnum;
bio = r10_bio->devs[i].bio;
bio->bi_end_io = NULL;
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
if (conf->mirrors[d].rdev == NULL ||
test_bit(Faulty, &conf->mirrors[d].rdev->flags))
continue;
@@ -2037,6 +2038,11 @@
/* 'size' is now the number of chunks in the array */
/* calculate "used chunks per device" in 'stride' */
stride = size * conf->copies;
+
+ /* We need to round up when dividing by raid_disks to
+ * get the stride size.
+ */
+ stride += conf->raid_disks - 1;
sector_div(stride, conf->raid_disks);
mddev->size = stride << (conf->chunk_shift-1);