block: add fault injection mechanism for faking request timeouts

Only works for the generic request timer handling. Allows one to
sporadically ignore request completions, thus exercising the timeout
handling.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index 7ab344afb16..e660d26ca65 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -154,6 +154,8 @@ do_local:
  **/
 void blk_complete_request(struct request *req)
 {
+	if (unlikely(blk_should_fake_timeout(req->q)))
+		return;
 	if (!blk_mark_rq_complete(req))
 		__blk_complete_request(req);
 }