+
+static void aio_op(struct bio *bio, struct iovec *iov, unsigned i, int opcode)
+{
+ ssize_t ret;
+ struct iocb iocb = {
+ .data = bio,
+ .aio_fildes = bio->bi_bdev->bd_fd,
+ .aio_rw_flags = bio->bi_opf & REQ_FUA ? RWF_SYNC : 0,
+ .aio_lio_opcode = opcode,
+ .u.c.buf = iov,
+ .u.c.nbytes = i,
+ .u.c.offset = bio->bi_iter.bi_sector << 9,
+
+ }, *iocbp = &iocb;
+
+ atomic_inc(&running_requests);
+
+ wait_event(aio_events_completed,
+ (ret = io_submit(aio_ctx, 1, &iocbp)) != -EAGAIN);;
+
+ if (ret != 1)
+ die("io_submit err: %s", strerror(-ret));
+}
+
+static void aio_read(struct bio *bio, struct iovec *iov, unsigned i)
+{
+ aio_op(bio, iov, i, IO_CMD_PREADV);
+}
+
+static void aio_write(struct bio *bio, struct iovec * iov, unsigned i)
+{
+ aio_op(bio, iov, i, IO_CMD_PWRITEV);
+}
+
+
+/* not implemented */
+static void uring_init(void) {
+ io_fallback();
+}
+
+struct fops fops_list[] = {
+ {
+ .init = uring_init,
+ }, {
+ .init = aio_init,
+ .cleanup = aio_cleanup,
+ .read = aio_read,
+ .write = aio_write,
+ }, {
+ .init = sync_init,
+ .cleanup = sync_cleanup,
+ .read = sync_read,
+ .write = sync_write,
+ }, {
+ /* NULL */
+ }
+};
+
+__attribute__((constructor(102)))
+static void blkdev_init(void)
+{
+ fops = fops_list;
+ fops->init();
+}
+
+__attribute__((destructor(102)))
+static void blkdev_cleanup(void)
+{
+ fops->cleanup();
+}