bcachefs: Fix error path in bch2_journal_flush_device_pins()

We need to always call bch2_replicas_gc_end() after we've called
bch2_replicas_gc_start(), else we leave state around that needs to be
cleaned up.

Partial fix for: https://github.com/koverstreet/bcachefs/issues/560Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/journal_reclaim.c

@@ -845,10 +845,8 @@ int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
 	 * expects to find devices marked for journal data on unclean mount.
 	 */
 	ret = bch2_journal_meta(&c->journal);
-	if (ret) {
-		mutex_unlock(&c->replicas_gc_lock);
-		return ret;
-	}
+	if (ret)
+		goto err;
 
 	seq = 0;
 	spin_lock(&j->lock);
@@ -867,7 +865,7 @@ int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
 		spin_lock(&j->lock);
 	}
 	spin_unlock(&j->lock);
-
+err:
 	ret = bch2_replicas_gc_end(c, ret);
 	mutex_unlock(&c->replicas_gc_lock);
 

fs/bcachefs/replicas.c

@@ -462,6 +462,9 @@ int bch2_replicas_gc_end(struct bch_fs *c, int ret)
 {
 	lockdep_assert_held(&c->replicas_gc_lock);
 
+	if (ret)
+		goto err;
+
 	mutex_lock(&c->sb_lock);
 	percpu_down_write(&c->mark_lock);