From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: Mon, 29 Nov 2021 10:00:43 +0000 (+0900)
Subject: loop: Use pr_warn_once() for loop_control_remove() warning
X-Git-Tag: v6.6.17~8536^2~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e3f9387aea67742b9d1f4de8e5bb2fd08a8a4584;p=platform%2Fkernel%2Flinux-rpi.git

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>
---

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a154cab..c3a36cf 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;
 	}