+int
+__block_read_page(struct device* dev, void* buf, size_t offset)
+{
+ struct vecbuf* vbuf = NULL;
+ struct block_dev* bdev = (struct block_dev*)dev->underlay;
+
+ u32_t lba = offset / bdev->blk_size + bdev->start_lba;
+ u32_t rd_lba = MIN(lba + PG_SIZE / bdev->blk_size, bdev->end_lba);
+
+ if (rd_lba <= lba) {
+ return 0;
+ }
+
+ rd_lba -= lba;
+
+ vbuf_alloc(&vbuf, buf, rd_lba * bdev->blk_size);
+
+ struct blkio_req* req = blkio_vrd(vbuf, lba, NULL, NULL, 0);
+
+ blkio_commit(bdev->blkio, req, BLKIO_WAIT);
+
+ int errno = req->errcode;
+ if (!errno) {
+ errno = rd_lba * bdev->blk_size;
+ } else {
+ errno = -errno;
+ }
+
+ blkio_free_req(req);
+ vbuf_free(vbuf);
+ return errno;
+}
+
+int
+__block_write_page(struct device* dev, void* buf, size_t offset)
+{
+ struct vecbuf* vbuf = NULL;
+ struct block_dev* bdev = (struct block_dev*)dev->underlay;
+
+ u32_t lba = offset / bdev->blk_size + bdev->start_lba;
+ u32_t rd_lba = MIN(lba + PG_SIZE / bdev->blk_size, bdev->end_lba);
+
+ if (rd_lba <= lba) {
+ return 0;
+ }
+
+ rd_lba -= lba;
+
+ vbuf_alloc(&vbuf, buf, rd_lba * bdev->blk_size);
+
+ struct blkio_req* req = blkio_vwr(vbuf, lba, NULL, NULL, 0);
+
+ blkio_commit(bdev->blkio, req, BLKIO_WAIT);
+
+ int errno = req->errcode;
+ if (!errno) {
+ errno = rd_lba * bdev->blk_size;
+ } else {
+ errno = -errno;
+ }
+
+ blkio_free_req(req);
+ vbuf_free(vbuf);
+ return errno;
+}
+
+int
+__block_rd_lb(struct block_dev* bdev, void* buf, u64_t start, size_t count)
+{
+ struct vecbuf* vbuf = NULL;
+ vbuf_alloc(&vbuf, buf, bdev->blk_size * count);
+
+ struct blkio_req* req = blkio_vrd(vbuf, start, NULL, NULL, 0);
+ blkio_commit(bdev->blkio, req, BLKIO_WAIT);
+
+ int errno = req->errcode;
+ if (!errno) {
+ errno = count;
+ } else {
+ errno = -errno;
+ }
+
+ blkio_free_req(req);
+ vbuf_free(vbuf);
+
+ return errno;
+}
+
+int
+__block_wr_lb(struct block_dev* bdev, void* buf, u64_t start, size_t count)
+{
+ struct vecbuf* vbuf = NULL;
+ vbuf_alloc(&vbuf, buf, bdev->blk_size * count);
+
+ struct blkio_req* req = blkio_vwr(vbuf, start, NULL, NULL, 0);
+ blkio_commit(bdev->blkio, req, BLKIO_WAIT);
+
+ int errno = req->errcode;
+ if (!errno) {
+ errno = count;
+ } else {
+ errno = -errno;
+ }
+
+ blkio_free_req(req);
+ vbuf_free(vbuf);
+
+ return errno;
+}
+
+void*
+block_alloc_buf(struct block_dev* bdev)
+{
+ return valloc(bdev->blk_size);
+}
+
+void
+block_free_buf(struct block_dev* bdev, void* buf)
+{
+ return vfree(buf);
+}
+