bcachefs: Don't try to delete stripes when RO

We weren't checking for errors when trying to delet stripes, which meant
ec_stripe_delete_work() would spin trying to delete the same stripe over
and over.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/ec.c

@@ -626,7 +626,8 @@ void bch2_stripes_heap_update(struct bch_fs *c,
 		bch2_stripes_heap_insert(c, m, idx);
 	}
 
-	if (stripe_idx_to_delete(c) >= 0)
+	if (stripe_idx_to_delete(c) >= 0 &&
+	    !percpu_ref_is_dying(&c->writes))
 		schedule_work(&c->ec_stripe_delete_work);
 }
 
@@ -684,7 +685,8 @@ static void ec_stripe_delete_work(struct work_struct *work)
 		if (idx < 0)
 			break;
 
-		ec_stripe_delete(c, idx);
+		if (ec_stripe_delete(c, idx))
+			break;
 	}
 
 	mutex_unlock(&c->ec_stripe_create_lock);

fs/bcachefs/super.c

@@ -366,6 +366,8 @@ static int bch2_fs_read_write_late(struct bch_fs *c)
 
 	schedule_delayed_work(&c->pd_controllers_update, 5 * HZ);
 
+	schedule_work(&c->ec_stripe_delete_work);
+
 	return 0;
 }