From c008f1d356277a5b7561040596a073d87e56b0c8 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Fri, 12 Jun 2015 19:46:44 +1000
Subject: md: don't return 0 from array_state_store

Returning zero from a 'store' function is bad.
The return value should be either len length of the string
or an error.

So use 'len' if 'err' is zero.

Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.")
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel (v4.0+)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 2750630..dd59d71 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3834,7 +3834,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
 				err = -EBUSY;
 		}
 		spin_unlock(&mddev->lock);
-		return err;
+		return err ?: len;
 	}
 	err = mddev_lock(mddev);
 	if (err)
-- 
cgit v0.10.2