From 802cc73b490c296d2891a60520f7abc615b270e8 Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <tst@1und1.de>
Date: Mon, 19 Jan 2015 10:09:33 +0100
Subject: [PATCH] infra: additionally safeguard race on brick resource
 deallocation

---
 kernel/sy_old/sy_generic.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/sy_old/sy_generic.c b/kernel/sy_old/sy_generic.c
index 4cb3eb82..cec63238 100644
--- a/kernel/sy_old/sy_generic.c
+++ b/kernel/sy_old/sy_generic.c
@@ -1475,7 +1475,9 @@ restart:
 	}
 	for (tmp = anchor->next; tmp != anchor; tmp = tmp->next) {
 		struct mars_brick *brick;
+		int count;
 		int status;
+
 		if (use_dent_link) {
 			brick = container_of(tmp, struct mars_brick, dent_brick_link);
 		} else {
@@ -1496,6 +1498,10 @@ restart:
 		if (!even_on && (brick->power.button || !brick->power.led_off)) {
 			continue;
 		}
+		// only kill bricks which have no resources allocated
+		count = atomic_read(&brick->mref_object_layout.alloc_count);
+		if (count > 0)
+			continue;
 		/* Workaround FIXME:
 		 * only kill bricks which have not been touched during the current mars_dent_work() round.
 		 * some bricks like aio seem to have races between startup and termination of threads.