+static int bch2_gc_write_reflink_key(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k,
+ size_t *idx)
+{
+ struct bch_fs *c = trans->c;
+ const __le64 *refcount = bkey_refcount_c(k);
+ struct printbuf buf = PRINTBUF;
+ struct reflink_gc *r;
+ int ret = 0;
+
+ if (!refcount)
+ return 0;
+
+ while ((r = genradix_ptr(&c->reflink_gc_table, *idx)) &&
+ r->offset < k.k->p.offset)
+ ++*idx;
+
+ if (!r ||
+ r->offset != k.k->p.offset ||
+ r->size != k.k->size) {
+ bch_err(c, "unexpected inconsistency walking reflink table at gc finish");
+ return -EINVAL;
+ }
+
+ if (fsck_err_on(r->refcount != le64_to_cpu(*refcount), c,
+ "reflink key has wrong refcount:\n"
+ " %s\n"
+ " should be %u",
+ (bch2_bkey_val_to_text(&buf, c, k), buf.buf),
+ r->refcount)) {
+ struct bkey_i *new = bch2_bkey_make_mut(trans, k);
+
+ ret = PTR_ERR_OR_ZERO(new);
+ if (ret)
+ return ret;
+
+ if (!r->refcount)
+ new->k.type = KEY_TYPE_deleted;
+ else
+ *bkey_refcount(new) = cpu_to_le64(r->refcount);
+
+ ret = bch2_trans_update(trans, iter, new, 0);
+ }
+fsck_err:
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int bch2_gc_reflink_done(struct bch_fs *c, bool metadata_only)
+{
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ size_t idx = 0;
+ int ret = 0;
+
+ if (metadata_only)
+ return 0;
+
+ bch2_trans_init(&trans, c, 0, 0);
+
+ ret = for_each_btree_key_commit(&trans, iter,
+ BTREE_ID_reflink, POS_MIN,
+ BTREE_ITER_PREFETCH, k,
+ NULL, NULL, BTREE_INSERT_NOFAIL,
+ bch2_gc_write_reflink_key(&trans, &iter, k, &idx));
+
+ c->reflink_gc_nr = 0;
+ bch2_trans_exit(&trans);
+ return ret;
+}
+
+static int bch2_gc_reflink_start(struct bch_fs *c,
+ bool metadata_only)
+{
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct reflink_gc *r;
+ int ret = 0;
+
+ if (metadata_only)
+ return 0;
+
+ bch2_trans_init(&trans, c, 0, 0);
+ c->reflink_gc_nr = 0;
+
+ for_each_btree_key(&trans, iter, BTREE_ID_reflink, POS_MIN,
+ BTREE_ITER_PREFETCH, k, ret) {
+ const __le64 *refcount = bkey_refcount_c(k);
+
+ if (!refcount)
+ continue;
+
+ r = genradix_ptr_alloc(&c->reflink_gc_table, c->reflink_gc_nr++,
+ GFP_KERNEL);
+ if (!r) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ r->offset = k.k->p.offset;
+ r->size = k.k->size;
+ r->refcount = 0;
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+
+ bch2_trans_exit(&trans);
+ return ret;
+}
+
+static void bch2_gc_reflink_reset(struct bch_fs *c, bool metadata_only)
+{
+ struct genradix_iter iter;
+ struct reflink_gc *r;