md: don't return 0 from array_state_store

commit c008f1d356277a5b7561040596a073d87e56b0c8 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5333d61..b7bf8ee 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3765,7 +3765,7 @@ 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)