1From 41edf6f45895193f4a523cb0a08d639c9ff9ccc9 Mon Sep 17 00:00:00 2001
2From: Logan Gunthorpe <logang@deltatee.com>
3Date: Wed, 22 Jun 2022 14:25:12 -0600
4Subject: [PATCH] mdadm: Fix optional --write-behind parameter
5
6The commit noted below changed the behaviour of --write-behind to
7require an argument. This broke the 06wrmostly test with the error:
8
9  mdadm: Invalid value for maximum outstanding write-behind writes: (null).
10         Must be between 0 and 16383.
11
12To fix this, check if optarg is NULL before parising it, as the origial
13code did.
14
15Upstream-Status: Backport [https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/commit/?id=41edf6f45895193f4a523cb0a08d639c9ff9ccc9]
16
17Fixes: 60815698c0ac ("Refactor parse_num and use it to parse optarg.")
18Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
19Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
20Acked-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
21Signed-off-by: Jes Sorensen <jes@trained-monkey.org>
22Signed-off-by: Mingli Yu <mingli.yu@windriver.com>
23---
24 mdadm.c | 5 +++--
25 1 file changed, 3 insertions(+), 2 deletions(-)
26
27diff --git a/mdadm.c b/mdadm.c
28index d0c5e6de..56722ed9 100644
29--- a/mdadm.c
30+++ b/mdadm.c
31@@ -1201,8 +1201,9 @@ int main(int argc, char *argv[])
32 		case O(BUILD, WriteBehind):
33 		case O(CREATE, WriteBehind):
34 			s.write_behind = DEFAULT_MAX_WRITE_BEHIND;
35-			if (parse_num(&s.write_behind, optarg) != 0 ||
36-			s.write_behind < 0 || s.write_behind > 16383) {
37+			if (optarg &&
38+			    (parse_num(&s.write_behind, optarg) != 0 ||
39+			     s.write_behind < 0 || s.write_behind > 16383)) {
40 				pr_err("Invalid value for maximum outstanding write-behind writes: %s.\n\tMust be between 0 and 16383.\n",
41 						optarg);
42 				exit(2);
43--
442.25.1
45
46