On Thu, 14 May 2015 13:55:08 +0800 Yuanhan Liu [off-list ref]
wrote:

On Thu, May 14, 2015 at 03:45:11PM +1000, NeilBrown wrote:

quoted

On Wed, 29 Apr 2015 10:48:55 +0800 Yuanhan Liu [off-list ref]
wrote:

quoted

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 64d5bea..697d77a 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c

@@ -344,7 +344,8 @@ static void release_inactive_stripe_list(struct r5conf *conf,
 					 int hash)
 {
 	int size;
-	bool do_wakeup = false;
+	unsigned long do_wakeup = 0;
+	int i = 0;
 	unsigned long flags;
 
 	if (hash == NR_STRIPE_HASH_LOCKS) {

@@ -365,15 +366,19 @@ static void release_inactive_stripe_list(struct r5conf *conf,
 			    !list_empty(list))
 				atomic_dec(&conf->empty_inactive_list_nr);
 			list_splice_tail_init(list, conf->inactive_list + hash);
-			do_wakeup = true;
+			do_wakeup |= 1 << (size - 1);
 			spin_unlock_irqrestore(conf->hash_locks + hash, flags);
 		}
 		size--;
 		hash--;
 	}
 
+	for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++) {
+		if (do_wakeup & (1 << i))
+			wake_up(&conf->wait_for_stripe[i]);
+	}
+

hi,
 I've been doing some testing and got a lock-up in resize_stripes, waiting
 on wait_for_stripe[].

 Looking at the above code,  I think
      do_wakeup |= 1 << (size - 1);
 should be
      do_wakeup |= 1 << hash;

 do you agree?  Or am I missing something?

Right. Sorry for the careless mistake.

Thanks for confirming.
Mistakes happen - that's why we test :-)

I've merged that fix into your patch.

NeilBrown