Re: [PATCH] blk-iocost: Fix overflow in donation weight calculation

[Jens Axboe]

On Fri, 13 Nov 2026 15:08:40 +0400, Alex Kazinsky wrote:
> hweight_after_donation() receives usage as u32, clamped to the range
> [1, WEIGHT_ONE]. Since WEIGHT_ONE is 1 << 16, multiplying it by usage
> equal to WEIGHT_ONE wraps the 32-bit unsigned result to zero before
> it is passed to div64_s64().
> 
> This makes new_hwi zero, which is then clamped to 1, incorrectly
> reducing the cgroup's in-use weight to the minimum.
> 
> [...]

Applied, thanks!

[1/1] blk-iocost: Fix overflow in donation weight calculation
      commit: a56d5a485be4a9d52f0d7b3ed0dc3521367cb986

Best regards,
-- 
Jens Axboe