[2.6.20.16 review 13/28] md: Fix two raid10 bugs.

From: Willy Tarreau
Date: Sat Aug 11 2007 - 15:00:09 EST


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@xxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/md/raid10.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)

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 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
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 @@ static int run(mddev_t *mddev)
/* '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);

--
1.5.2.4

--
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