[PATCH 3.12 096/142] md/raid10: Fix memory leak when raid10 reshape completes.

From: Jiri Slaby
Date: Fri Sep 26 2014 - 06:15:47 EST


From: NeilBrown <neilb@xxxxxxx>

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

===============

commit b39685526f46976bcd13aa08c82480092befa46c upstream.

When a raid10 commences a resync/recovery/reshape it allocates
some buffer space.
When a resync/recovery completes the buffer space is freed. But not
when the reshape completes.
This can result in a small memory leak.

There is a subtle side-effect of this bug. When a RAID10 is reshaped
to a larger array (more devices), the reshape is immediately followed
by a "resync" of the new space. This "resync" will use the buffer
space which was allocated for "reshape". This can cause problems
including a "BUG" in the SCSI layer. So this is suitable for -stable.

Fixes: 3ea7daa5d7fde47cd41f4d56c2deb949114da9d6
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/md/raid10.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index d1cf7734e55e..9ccb107c982e 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2969,6 +2969,7 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
*/
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
end_reshape(conf);
+ close_sync(conf);
return 0;
}

--
2.1.0

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