bcachefs: Extra kthread_should_stop() calls for copygc

This fixes a bug where going read-only was taking longer than it should
have due to copygc forgetting to check kthread_should_stop()

Additionally: fix a missing is_kthread check in bch2_move_ratelimit().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/move.c

@@ -441,24 +441,26 @@ int bch2_move_get_io_opts_one(struct btree_trans *trans,
 int bch2_move_ratelimit(struct moving_context *ctxt)
 {
 	struct bch_fs *c = ctxt->trans->c;
+	bool is_kthread = current->flags & PF_KTHREAD;
 	u64 delay;
 
 	if (ctxt->wait_on_copygc && c->copygc_running) {
 		bch2_moving_ctxt_flush_all(ctxt);
 		wait_event_killable(c->copygc_running_wq,
 				    !c->copygc_running ||
-				    kthread_should_stop());
+				    (is_kthread && kthread_should_stop()));
 	}
 
 	do {
 		delay = ctxt->rate ? bch2_ratelimit_delay(ctxt->rate) : 0;
 
-		if ((current->flags & PF_KTHREAD) && kthread_should_stop())
+		if (is_kthread && kthread_should_stop())
 			return 1;
 
 		if (delay)
 			move_ctxt_wait_event_timeout(ctxt,
-					freezing(current) || kthread_should_stop(),
+					freezing(current) ||
+					(is_kthread && kthread_should_stop()),
 					delay);
 
 		if (unlikely(freezing(current))) {
@@ -633,6 +635,7 @@ int __bch2_evacuate_bucket(struct moving_context *ctxt,
 {
 	struct btree_trans *trans = ctxt->trans;
 	struct bch_fs *c = trans->c;
+	bool is_kthread = current->flags & PF_KTHREAD;
 	struct bch_io_opts io_opts = bch2_opts_to_inode_opts(c->opts);
 	struct btree_iter iter;
 	struct bkey_buf sk;
@@ -678,6 +681,9 @@ int __bch2_evacuate_bucket(struct moving_context *ctxt,
 	}
 
 	while (!(ret = bch2_move_ratelimit(ctxt))) {
+		if (is_kthread && kthread_should_stop())
+			break;
+
 		bch2_trans_begin(trans);
 
 		ret = bch2_get_next_backpointer(trans, bucket, gen,

fs/bcachefs/movinggc.c

@@ -207,7 +207,7 @@ static int bch2_copygc(struct moving_context *ctxt,
 		goto err;
 
 	darray_for_each(buckets, i) {
-		if (unlikely(freezing(current)))
+		if (kthread_should_stop() || freezing(current))
 			break;
 
 		f = move_bucket_in_flight_add(buckets_in_flight, *i);