@@ -511,19 +511,37 @@ static void ublk_copy_io_pages(struct ublk_io_iter *data,
}
}
+static bool ublk_advance_io_iter(struct ublk_io_iter *iter, unsigned int offset)
+{
+ struct bio *bio = iter->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,
- 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,
};
size_t done = 0;
+ if (!ublk_advance_io_iter(&iter, offset))
+ return 0;
+
while (iov_iter_count(uiter) && iter.bio) {
unsigned nr_pages;
size_t len, off;
@@ -576,7 +594,7 @@ static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req,
import_single_range(dir, (void __user *)io->addr,
rq_bytes, &iov, &iter);
- return ublk_copy_user_pages(req, &iter, dir);
+ return ublk_copy_user_pages(req, 0, &iter, dir);
}
return rq_bytes;
}
@@ -596,7 +614,7 @@ static int ublk_unmap_io(const struct ublk_queue *ubq,
import_single_range(dir, (void __user *)io->addr,
io->res, &iov, &iter);
- return ublk_copy_user_pages(req, &iter, dir);
+ return ublk_copy_user_pages(req, 0, &iter, dir);
}
return rq_bytes;
}
Add 'offset' to 'struct ublk_map_data', so that ublk_copy_user_pages() can be used to copy any sub-buffer(linear mapped) of the request. Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/block/ublk_drv.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-)