Comment # 6 on bug 1051686 from Jeff Mahoney

linux-4.4-openSUSE-42.3/drivers/md/bcache> grep -r EINTR .
./request.c:        s->iop.error = -EINTR;
./request.c:    ret = miss == bio ? MAP_DONE : -EINTR;
./btree.c: * going to have to split), set op->lock and return -EINTR;
btree_root() will
./btree.c:    int _r = -EINTR;                        \
./btree.c:        if (_r == -EINTR)                    \
./btree.c:    } while (_r == -EINTR);                        \
./btree.c:        return -EINTR;
./btree.c:        return ERR_PTR(-EINTR);
./btree.c:            return -EINTR;
./btree.c:    r[nodes - 1].b = ERR_PTR(-EINTR);
./btree.c:    return -EINTR;
./btree.c:    return -EINTR;
./btree.c:        i->b = ERR_PTR(-EINTR);
./btree.c:            return -EINTR;
./btree.c:            return -EINTR;
./btree.c:        return -EINTR;
./btree.c:            return -EINTR;
./btree.c:    int ret = -EINTR;
./btree.c:        w->private = ERR_PTR(-EINTR);
./btree.h: * the lock field and returns -EINTR, which causes the btree_root()
macro to
./super.c:        return -EINTR;
./movinggc.c:        io->op.error = -EINTR;

That looks more promising, though.  Coly, could you take a look here?