+static bool ublk_advance_io_iter(const struct request *req,
+ struct ublk_io_iter *iter, unsigned int offset)
+{
+ struct bio *bio = req->bio;
+
+ for_each_bio(bio) {
+ if (bio->bi_iter.bi_size > offset) {
+ iter->bio = bio;
+ iter->iter = bio->bi_iter;
+ bio_advance_iter(iter->bio, &iter->iter, offset);
+ return true;
+ }
+ offset -= bio->bi_iter.bi_size;
+ }
+ return false;
+}
+
/*
* Copy data between request pages and io_iter, and 'offset'
* is the start point of linear offset of request.
*/
static size_t ublk_copy_user_pages(const struct request *req,
/*
* Copy data between request pages and io_iter, and 'offset'
* is the start point of linear offset of request.
*/
static size_t ublk_copy_user_pages(const struct request *req,
- struct iov_iter *uiter, int dir)
+ unsigned offset, struct iov_iter *uiter, int dir)
- struct ublk_io_iter iter = {
- .bio = req->bio,
- .iter = req->bio->bi_iter,
- };
+ struct ublk_io_iter iter;
+ if (!ublk_advance_io_iter(req, &iter, offset))
+ return 0;
+
while (iov_iter_count(uiter) && iter.bio) {
unsigned nr_pages;
size_t len, off;
while (iov_iter_count(uiter) && iter.bio) {
unsigned nr_pages;
size_t len, off;
import_single_range(dir, u64_to_user_ptr(io->addr), rq_bytes,
&iov, &iter);
import_single_range(dir, u64_to_user_ptr(io->addr), rq_bytes,
&iov, &iter);
- return ublk_copy_user_pages(req, &iter, dir);
+ return ublk_copy_user_pages(req, 0, &iter, dir);
import_single_range(dir, u64_to_user_ptr(io->addr), io->res,
&iov, &iter);
import_single_range(dir, u64_to_user_ptr(io->addr), io->res,
&iov, &iter);
- return ublk_copy_user_pages(req, &iter, dir);
+ return ublk_copy_user_pages(req, 0, &iter, dir);