From a7f3dfb8293c4cee99743132d69863a92e8f4875 Mon Sep 17 00:00:00 2001 From: Thorsten Blum Date: Mon, 1 Sep 2025 17:01:44 +0200 Subject: [PATCH] btrfs: scrub: replace max_t()/min_t() with clamp() in scrub_throttle_dev_io() Replace max_t() followed by min_t() with a single clamp(). As was pointed by David Laight in https://lore.kernel.org/linux-btrfs/20250906122458.75dfc8f0@pumpkin/ the calculation may overflow u32 when the input value is too large, so clamp_t() is not used. In practice the expected values are in range of megabytes to gigabytes (throughput limit) so the bug would not happen. Signed-off-by: Thorsten Blum Reviewed-by: David Sterba [ Use clamp() and add explanation. ] Signed-off-by: David Sterba --- fs/btrfs/scrub.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index d86020ace69c6..2f10c65929dc9 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -1369,8 +1369,7 @@ static void scrub_throttle_dev_io(struct scrub_ctx *sctx, struct btrfs_device *d * Slice is divided into intervals when the IO is submitted, adjust by * bwlimit and maximum of 64 intervals. */ - div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024))); - div = min_t(u32, 64, div); + div = clamp(bwlimit / (16 * 1024 * 1024), 1, 64); /* Start new epoch, set deadline */ now = ktime_get(); -- 2.47.3