From 9dac8acd0a87f21ef382bec3a01c26634f1c5acc Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: Mon, 29 Nov 2021 19:00:43 +0900
Subject: [PATCH] loop: Use pr_warn_once() for loop_control_remove() warning

kernel test robot reported that RCU stall via printk() flooding is
possible [1] when stress testing.

Link: https://lkml.kernel.org/r/20211129073709.GA18483@xsang-OptiPlex-9020 [1]
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/block/loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a154cab6cd989..c3a36cfaa855a 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2103,7 +2103,7 @@ static int loop_control_remove(int idx)
 	int ret;
 
 	if (idx < 0) {
-		pr_warn("deleting an unspecified loop device is not supported.\n");
+		pr_warn_once("deleting an unspecified loop device is not supported.\n");
 		return -EINVAL;
 	}
 		
-- 
2.39.5