There is a hole at the end of 'struct bvec_iter', so put a new field
here and we can save cookie returned from submit_bio() here for
supporting bio based polling.
This way can avoid to extend bio unnecessarily.
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
include/linux/bvec.h | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index ff832e698efb..61c0f55f7165 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -43,6 +43,15 @@ struct bvec_iter {
unsigned int bi_bvec_done; /* number of bytes completed in
current bvec */
+
+ /*
+ * There is a hole at the end of bvec_iter, define one filed to
+ * hold something which isn't relate with 'bvec_iter', so that we can
+ * avoid to extend bio. So far this new field is used for bio based
+ * pooling, we will store returning value of underlying queue's
+ * submit_bio() here.
+ */
+ unsigned int bi_private_data;
};
struct bvec_iter_all {
--
2.29.2
--
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