From 2459bd33b3dbb7a34f28c612d595311a6bc7593d Mon Sep 17 00:00:00 2001
From: Vincent Fu <vincent.fu@samsung.com>
Date: Wed, 4 Aug 2021 18:29:05 +0000
Subject: [PATCH] ioengines: fix crash with --enghelp option

Since f6931a1dd35896433c8cc2e10de51372a2c496c4 commands like the
following segfault:

fio --enghelp=sg
fio --enghelp=sg,sg_write_mode

This is because free_ioengine() assumes that td->io_ops is not NULL.
Make this true when free_ioengine() is called by
fio_show_ioengine_help() to avoid the crash.

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 ioengines.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/ioengines.c b/ioengines.c
index dd61af07..d08a511a 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -692,17 +692,17 @@ int fio_show_ioengine_help(const char *engine)
 	}
 
 	td.o.ioengine = (char *)engine;
-	io_ops = load_ioengine(&td);
+	td.io_ops = load_ioengine(&td);
 
-	if (!io_ops) {
+	if (!td.io_ops) {
 		log_info("IO engine %s not found\n", engine);
 		return 1;
 	}
 
-	if (io_ops->options)
-		ret = show_cmd_help(io_ops->options, sep);
+	if (td.io_ops->options)
+		ret = show_cmd_help(td.io_ops->options, sep);
 	else
-		log_info("IO engine %s has no options\n", io_ops->name);
+		log_info("IO engine %s has no options\n", td.io_ops->name);
 
 	free_ioengine(&td);
 	return ret;
-- 
2.17.0