[SCSI] block: fix the partial mappings with struct rq_map_data
This fixes bio_copy_user_iov to properly handle the partial mappings
with struct rq_map_data (which only sg uses for now but st and osst
will shortly). It adds the offset member to struct rq_map_data and
changes blk_rq_map_user to update it so that bio_copy_user_iov can add
an appropriate page frame via bio_add_pc_page().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 5103855..7d0b3d9 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1669,6 +1669,7 @@
md->pages = req_schp->pages;
md->page_order = req_schp->page_order;
md->nr_entries = req_schp->k_use_sg;
+ md->offset = 0;
}
if (iov_count)