[PATCH 002 of 3] md: Clear the congested_fn when stopping a raid5

[NeilBrown <neilb@suse.de>]

If this mddev and queue got reused for another array that doesn't
register a congested_fn, this function would get called incorretly.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
 ./drivers/md/md.c    |    1 +
 ./drivers/md/raid5.c |    3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff .prev/drivers/md/md.c ./drivers/md/md.c
--- .prev/drivers/md/md.c	2007-03-23 11:13:41.000000000 +1100
+++ ./drivers/md/md.c	2007-03-23 11:13:41.000000000 +1100
@@ -3325,6 +3325,7 @@ static int do_md_stop(mddev_t * mddev, i
 			mddev->queue->merge_bvec_fn = NULL;
 			mddev->queue->unplug_fn = NULL;
 			mddev->queue->issue_flush_fn = NULL;
+			mddev->queue->backing_dev_info.congested_fn = NULL;
 			if (mddev->pers->sync_request)
 				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
 

diff .prev/drivers/md/raid5.c ./drivers/md/raid5.c
--- .prev/drivers/md/raid5.c	2007-03-23 11:13:29.000000000 +1100
+++ ./drivers/md/raid5.c	2007-03-23 11:13:41.000000000 +1100
@@ -4269,8 +4269,8 @@ static int run(mddev_t *mddev)
 
 	mddev->queue->unplug_fn = raid5_unplug_device;
 	mddev->queue->issue_flush_fn = raid5_issue_flush;
-	mddev->queue->backing_dev_info.congested_fn = raid5_congested;
 	mddev->queue->backing_dev_info.congested_data = mddev;
+	mddev->queue->backing_dev_info.congested_fn = raid5_congested;
 
 	mddev->array_size =  mddev->size * (conf->previous_raid_disks -
 					    conf->max_degraded);
@@ -4301,6 +4301,7 @@ static int stop(mddev_t *mddev)
 	mddev->thread = NULL;
 	shrink_stripes(conf);
 	kfree(conf->stripe_hashtbl);
+	mddev->queue->backing_dev_info.congested_fn = NULL;
 	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
 	sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
 	kfree(conf->disks);