[PATCH AUTOSEL 5.15 10/24] loop: Use pr_warn_once() for loop_control_remove() warning

Sasha Levin
2021-12-06T21:14:08Z

From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>

[ Upstream commit e3f9387aea67742b9d1f4de8e5bb2fd08a8a4584 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 dfc72a1f6500d..c00ae30fde89e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2429,7 +2429,7 @@ 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;
}

--
2.33.0