md: raid1/raid10: fix problem with merge_bvec_fn
commit aba336bd1d46d6b0404b06f6915ed76150739057 upstream.
The new merge_bvec_fn which calls the corresponding function
in subsidiary devices requires that mddev->merge_check_needed
be set if any child has a merge_bvec_fn.
However were were only setting that when a device was hot-added,
not when a device was present from the start.
This bug was introduced in 3.4 so patch is suitable for 3.4.y
kernels. However that are conflicts in raid10.c so a separate
patch will be needed for 3.4.y.
Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3f91c2e..d037adb 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3311,7 +3311,7 @@
(conf->raid_disks / conf->near_copies));
rdev_for_each(rdev, mddev) {
-
+ struct request_queue *q;
disk_idx = rdev->raid_disk;
if (disk_idx >= conf->raid_disks
|| disk_idx < 0)
@@ -3327,6 +3327,9 @@
goto out_free_conf;
disk->rdev = rdev;
}
+ q = bdev_get_queue(rdev->bdev);
+ if (q->merge_bvec_fn)
+ mddev->merge_check_needed = 1;
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);