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, 12 insertions, 0 deletions

diff --git a/block/blk.h b/block/blk.h
index a4f4a50aefaa..e5c579769963 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -42,6 +42,18 @@ static inline void blk_clear_rq_complete(struct request *rq)
         clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
 }
 
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+int blk_should_fake_timeout(struct request_queue *);
+ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
+ssize_t part_timeout_store(struct device *, struct device_attribute *,
+                                const char *, size_t);
+#else
+static inline int blk_should_fake_timeout(struct request_queue *q)
+{
+        return 0;
+}
+#endif
+
 struct io_context *current_io_context(gfp_t gfp_flags, int node);
 
 int ll_back_merge_fn(struct request_queue *q, struct request *req,