From c629f345b436997e4483aff85ec93f32faf6e4e6 Mon Sep 17 00:00:00 2001
From: Logan Gunthorpe <logang@deltatee.com>
Date: Wed, 8 Jun 2022 10:27:49 -0600
Subject: [PATCH] md/raid5: suspend the array for calls to log_exit()
Git-commit: c629f345b436997e4483aff85ec93f32faf6e4e6
Patch-mainline: v6.0-rc1
References: jsc#PED-2766

The raid5-cache code relies on there being no IO in flight when
log_exit() is called. There are two places where this is not
guaranteed so add mddev_suspend() and mddev_resume() calls to these
sites.

The site in raid5_change_consistency_policy() is in the error path,
and another similar call site already has suspend/resume calls just
below it; so it should be equally safe to make that change here.

There is one remaining site in raid5_remove_disk() that we call log_exit()
without suspending the array. Unfortunately, as the comment stated, we
cannot call mddev_suspend from raid5d.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/raid5.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 5cabdbbac48b..9950f576a34e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -8704,8 +8704,11 @@ static int raid5_change_consistency_policy(struct mddev *mddev, const char *buf)
 			err = log_init(conf, NULL, true);
 			if (!err) {
 				err = resize_stripes(conf, conf->pool_size);
-				if (err)
+				if (err) {
+					mddev_suspend(mddev);
 					log_exit(conf);
+					mddev_resume(mddev);
+				}
 			}
 		} else
 			err = -EINVAL;
-- 
2.35.3