Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-5.9/driversfor-5.9/drivers-20200803

Pull MD fixes from Song.

* 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md/raid5: Allow degraded raid6 to do rmw
  md/raid5: Fix Force reconstruct-write io stuck in degraded raid5
  raid5: don't duplicate code for different paths in handle_stripe
  raid5-cache: hold spinlock instead of mutex in r5c_journal_mode_show
  md: print errno in super_written
  md/raid5: remove the redundant setting of STRIPE_HANDLE
  md: register new md sysfs file 'uuid' read-only
  md: fix max sectors calculation for super 1.0

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 82eb4a906e31..4337ae0e6af2 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -2537,13 +2537,10 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
 	struct r5conf *conf;
 	int ret;
 
-	ret = mddev_lock(mddev);
-	if (ret)
-		return ret;
-
+	spin_lock(&mddev->lock);
 	conf = mddev->private;
 	if (!conf || !conf->log) {
-		mddev_unlock(mddev);
+		spin_unlock(&mddev->lock);
 		return 0;
 	}
 
@@ -2563,7 +2560,7 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
 	default:
 		ret = 0;
 	}
-	mddev_unlock(mddev);
+	spin_unlock(&mddev->lock);
 	return ret;
 }