Merge tag 'v4.4.51' into linux-linaro-lsk-v4.4

 This is the 4.4.51 stable release

1 files changed, 20 insertions, 20 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 22b9e34ceb75..5b815e64c1c9 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1762,33 +1762,34 @@ static void bch_btree_gc(struct cache_set *c)
 	bch_moving_gc(c);
 }
 
-static int bch_gc_thread(void *arg)
+static bool gc_should_run(struct cache_set *c)
 {
-	struct cache_set *c = arg;
 	struct cache *ca;
 	unsigned i;
 
-	while (1) {
-again:
-		bch_btree_gc(c);
+	for_each_cache(ca, c, i)
+		if (ca->invalidate_needs_gc)
+			return true;
 
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (kthread_should_stop())
-			break;
+	if (atomic_read(&c->sectors_to_gc) < 0)
+		return true;
 
-		mutex_lock(&c->bucket_lock);
+	return false;
+}
 
-		for_each_cache(ca, c, i)
-			if (ca->invalidate_needs_gc) {
-				mutex_unlock(&c->bucket_lock);
-				set_current_state(TASK_RUNNING);
-				goto again;
-			}
+static int bch_gc_thread(void *arg)
+{
+	struct cache_set *c = arg;
 
-		mutex_unlock(&c->bucket_lock);
+	while (1) {
+		wait_event_interruptible(c->gc_wait,
+			   kthread_should_stop() || gc_should_run(c));
 
-		try_to_freeze();
-		schedule();
+		if (kthread_should_stop())
+			break;
+
+		set_gc_sectors(c);
+		bch_btree_gc(c);
 	}
 
 	return 0;
@@ -1796,11 +1797,10 @@ again:
 
 int bch_gc_thread_start(struct cache_set *c)
 {
-	c->gc_thread = kthread_create(bch_gc_thread, c, "bcache_gc");
+	c->gc_thread = kthread_run(bch_gc_thread, c, "bcache_gc");
 	if (IS_ERR(c->gc_thread))
 		return PTR_ERR(c->gc_thread);
 
-	set_task_state(c->gc_thread, TASK_INTERRUPTIBLE);
 	return 0;
 }