+static struct bkey_s_c_dirent dirent_get_by_pos(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bpos pos)
+{
+ return bch2_bkey_get_iter_typed(trans, iter, BTREE_ID_dirents, pos, 0, dirent);
+}
+
+static struct bkey_s_c_dirent inode_get_dirent(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bch_inode_unpacked *inode,
+ u32 *snapshot)
+{
+ if (inode->bi_subvol) {
+ u64 inum;
+ int ret = subvol_lookup(trans, inode->bi_parent_subvol, snapshot, &inum);
+ if (ret)
+ return ((struct bkey_s_c_dirent) { .k = ERR_PTR(ret) });
+ }
+
+ return dirent_get_by_pos(trans, iter, SPOS(inode->bi_dir, inode->bi_dir_offset, *snapshot));
+}
+
+static bool inode_points_to_dirent(struct bch_inode_unpacked *inode,
+ struct bkey_s_c_dirent d)
+{
+ return inode->bi_dir == d.k->p.inode &&
+ inode->bi_dir_offset == d.k->p.offset;
+}
+
+static bool dirent_points_to_inode(struct bkey_s_c_dirent d,
+ struct bch_inode_unpacked *inode)
+{
+ return d.v->d_type == DT_SUBVOL
+ ? le32_to_cpu(d.v->d_child_subvol) == inode->bi_subvol
+ : le64_to_cpu(d.v->d_inum) == inode->bi_inum;
+}
+
+static int check_inode_deleted_list(struct btree_trans *trans, struct bpos p)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_deleted_inodes, p, 0);
+ int ret = bkey_err(k);
+ if (ret)
+ return ret;
+
+ bch2_trans_iter_exit(trans, &iter);
+ return k.k->type == KEY_TYPE_set;
+}
+
+static int check_inode_dirent_inode(struct btree_trans *trans, struct bkey_s_c inode_k,
+ struct bch_inode_unpacked *inode,
+ u32 inode_snapshot, bool *write_inode)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+
+ struct btree_iter dirent_iter = {};
+ struct bkey_s_c_dirent d = inode_get_dirent(trans, &dirent_iter, inode, &inode_snapshot);
+ int ret = bkey_err(d);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ return ret;
+
+ if (fsck_err_on(ret,
+ c, inode_points_to_missing_dirent,
+ "inode points to missing dirent\n%s",
+ (bch2_bkey_val_to_text(&buf, c, inode_k), buf.buf)) ||
+ fsck_err_on(!ret && !dirent_points_to_inode(d, inode),
+ c, inode_points_to_wrong_dirent,
+ "inode points to dirent that does not point back:\n%s",
+ (bch2_bkey_val_to_text(&buf, c, inode_k),
+ prt_newline(&buf),
+ bch2_bkey_val_to_text(&buf, c, d.s_c), buf.buf))) {
+ /*
+ * We just clear the backpointer fields for now. If we find a
+ * dirent that points to this inode in check_dirents(), we'll
+ * update it then; then when we get to check_path() if the
+ * backpointer is still 0 we'll reattach it.
+ */
+ inode->bi_dir = 0;
+ inode->bi_dir_offset = 0;
+ inode->bi_flags &= ~BCH_INODE_backptr_untrusted;
+ *write_inode = true;
+ }
+
+ ret = 0;
+fsck_err:
+ bch2_trans_iter_exit(trans, &dirent_iter);
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+}
+