An error path in the ZFS osd_object_create() applies PTR_ERR() to the valid thandle pointer:

        db = osd_create_type_f(dof->dof_type)(env, osd, attr, zapid, oh);
        if (IS_ERR(db))
                GOTO(out, rc = PTR_ERR(th));

Surely PTR_ERR(db) should be used instead. This was found using one of the coccinelle example scripts.

Also 'Quota' is misspelled in a comment.