+static int __bio_copy_iov(struct bio *bio, struct sg_iovec *iov, int iov_count,
+ int uncopy)
+{
+ int ret = 0, i;
+ struct bio_vec *bvec;
+ int iov_idx = 0;
+ unsigned int iov_off = 0;
+ int read = bio_data_dir(bio) == READ;
+
+ __bio_for_each_segment(bvec, bio, i, 0) {
+ char *bv_addr = page_address(bvec->bv_page);
+ unsigned int bv_len = bvec->bv_len;
+
+ while (bv_len && iov_idx < iov_count) {
+ unsigned int bytes;
+ char *iov_addr;
+
+ bytes = min_t(unsigned int,
+ iov[iov_idx].iov_len - iov_off, bv_len);
+ iov_addr = iov[iov_idx].iov_base + iov_off;
+
+ if (!ret) {
+ if (!read && !uncopy)
+ ret = copy_from_user(bv_addr, iov_addr,
+ bytes);
+ if (read && uncopy)
+ ret = copy_to_user(iov_addr, bv_addr,
+ bytes);
+
+ if (ret)
+ ret = -EFAULT;
+ }
+
+ bv_len -= bytes;
+ bv_addr += bytes;
+ iov_addr += bytes;
+ iov_off += bytes;
+
+ if (iov[iov_idx].iov_len == iov_off) {
+ iov_idx++;
+ iov_off = 0;
+ }
+ }
+
+ if (uncopy)
+ __free_page(bvec->bv_page);
+ }
+
+ return ret;
+}
+