5.15-stable review patch. If anyone has any objections, please let me know.
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From: Thorsten Blum thorsten.blum@linux.dev
[ Upstream commit a7f3dfb8293c4cee99743132d69863a92e8f4875 ]
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 thorsten.blum@linux.dev Reviewed-by: David Sterba dsterba@suse.com [ Use clamp() and add explanation. ] Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 6ffd34d39e992..aac4ee5880952 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2017,8 +2017,7 @@ static void scrub_throttle(struct scrub_ctx *sctx) * 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();