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@xxxxxxxxxx> --- drivers/block/ublk_drv.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 88d5a657834d..26a14c54da1d 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -511,19 +511,36 @@ static void ublk_copy_io_pages(struct ublk_io_iter *data, } } +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, - 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; size_t done = 0; + if (!ublk_advance_io_iter(req, &iter, offset)) + return 0; + while (iov_iter_count(uiter) && iter.bio) { unsigned nr_pages; size_t len, off; @@ -576,7 +593,7 @@ static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req, 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); } return rq_bytes; } @@ -596,7 +613,7 @@ static int ublk_unmap_io(const struct ublk_queue *ubq, 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); } return rq_bytes; } -- 2.39.2