1 files changed, 30 insertions, 24 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 22b9e34ceb75..4ed621ad27e4 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -808,7 +808,10 @@ int bch_btree_cache_alloc(struct cache_set *c)
 	c->shrink.scan_objects = bch_mca_scan;
 	c->shrink.seeks = 4;
 	c->shrink.batch = c->btree_pages * 2;
-	register_shrinker(&c->shrink);
+
+	if (register_shrinker(&c->shrink))
+		pr_warn("bcache: %s: could not register shrinker",
+				__func__);
 
 	return 0;
 }
@@ -1762,33 +1765,34 @@ 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 +1800,10 @@ 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;
 }
 
@@ -1866,14 +1869,17 @@ void bch_initial_gc_finish(struct cache_set *c)
 	 */
 	for_each_cache(ca, c, i) {
 		for_each_bucket(b, ca) {
-			if (fifo_full(&ca->free[RESERVE_PRIO]))
+			if (fifo_full(&ca->free[RESERVE_PRIO]) &&
+			    fifo_full(&ca->free[RESERVE_BTREE]))
 				break;
 
 			if (bch_can_invalidate_bucket(ca, b) &&
 			    !GC_MARK(b)) {
 				__bch_invalidate_one_bucket(ca, b);
-				fifo_push(&ca->free[RESERVE_PRIO],
-					  b - ca->buckets);
+				if (!fifo_push(&ca->free[RESERVE_PRIO],
+				   b - ca->buckets))
+					fifo_push(&ca->free[RESERVE_BTREE],
+						  b - ca->buckets);
 			}
 		}
 	}