block: avoid to merge splitted bio
The splitted bio has been already too fat to merge, so mark it
as NOMERGE.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 22293fd..de5716d8 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -139,6 +139,9 @@
bio_set_flag(res, BIO_SEG_VALID);
if (split) {
+ /* there isn't chance to merge the splitted bio */
+ split->bi_rw |= REQ_NOMERGE;
+
bio_chain(split, *bio);
generic_make_request(*bio);
*bio = split;