+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
+ struct bio_integrity_payload *bip, u64 lba,
+ int rw)
+{
+ unsigned int len = nd_blk_meta_size(blk_dev);
+ resource_size_t dev_offset, ns_offset;
+ struct nd_namespace_blk *nsblk;
+ struct nd_blk_region *ndbr;
+ int err = 0;
+
+ nsblk = blk_dev->nsblk;
+ ndbr = blk_dev->ndbr;
+ ns_offset = lba * blk_dev->internal_lbasize + blk_dev->sector_size;
+ dev_offset = to_dev_offset(nsblk, ns_offset, len);
+ if (dev_offset == SIZE_MAX)
+ return -EIO;
+
+ while (len) {
+ unsigned int cur_len;
+ struct bio_vec bv;
+ void *iobuf;
+
+ bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+ /*
+ * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
+ * .bv_offset already adjusted for iter->bi_bvec_done, and we
+ * can use those directly
+ */
+
+ cur_len = min(len, bv.bv_len);
+ iobuf = kmap_atomic(bv.bv_page);
+ err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
+ cur_len, rw);
+ kunmap_atomic(iobuf);
+ if (err)
+ return err;
+
+ len -= cur_len;
+ dev_offset += cur_len;
+ bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
+ }
+
+ return err;
+}
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
+ struct bio_integrity_payload *bip, u64 lba,
+ int rw)
+{
+ return 0;
+}
+#endif
+
+static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
+ struct bio_integrity_payload *bip, struct page *page,
+ unsigned int len, unsigned int off, int rw,
+ sector_t sector)
+{
+ struct nd_blk_region *ndbr = blk_dev->ndbr;
+ resource_size_t dev_offset, ns_offset;
+ int err = 0;
+ void *iobuf;
+ u64 lba;
+
+ while (len) {
+ unsigned int cur_len;
+
+ /*
+ * If we don't have an integrity payload, we don't have to
+ * split the bvec into sectors, as this would cause unnecessary
+ * Block Window setup/move steps. the do_io routine is capable
+ * of handling len <= PAGE_SIZE.
+ */
+ cur_len = bip ? min(len, blk_dev->sector_size) : len;
+
+ lba = div_u64(sector << SECTOR_SHIFT, blk_dev->sector_size);
+ ns_offset = lba * blk_dev->internal_lbasize;
+ dev_offset = to_dev_offset(blk_dev->nsblk, ns_offset, cur_len);
+ if (dev_offset == SIZE_MAX)
+ return -EIO;
+
+ iobuf = kmap_atomic(page);
+ err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
+ kunmap_atomic(iobuf);
+ if (err)
+ return err;
+
+ if (bip) {
+ err = nd_blk_rw_integrity(blk_dev, bip, lba, rw);
+ if (err)
+ return err;
+ }
+ len -= cur_len;
+ off += cur_len;
+ sector += blk_dev->sector_size >> SECTOR_SHIFT;
+ }
+
+ return err;
+}
+