[merged mm-hotfixes-stable] mm-fix-arithmetic-for-max_prop_frac-when-setting-max_ratio.patch removed from -mm tree

[merged mm-hotfixes-stable] mm-fix-arithmetic-for-max_prop_frac-when-setting-max_ratio.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: fix arithmetic for max_prop_frac when setting max_ratio
has been removed from the -mm tree.  Its filename was
     mm-fix-arithmetic-for-max_prop_frac-when-setting-max_ratio.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Jingbo Xu <jefflexu@linux.alibaba.com>
Subject: mm: fix arithmetic for max_prop_frac when setting max_ratio
Date: Tue, 19 Dec 2023 22:25:08 +0800

Since now bdi->max_ratio is part per million, fix the wrong arithmetic for
max_prop_frac when setting max_ratio.  Otherwise the miscalculated
max_prop_frac will affect the incrementing of writeout completion count
when max_ratio is not 100%.

Link: https://lkml.kernel.org/r/20231219142508.86265-3-jefflexu@linux.alibaba.com
Fixes: efc3e6ad53ea ("mm: split off __bdi_set_max_ratio() function")
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Stefan Roesch <shr@devkernel.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page-writeback.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/mm/page-writeback.c~mm-fix-arithmetic-for-max_prop_frac-when-setting-max_ratio
+++ a/mm/page-writeback.c
@@ -728,7 +728,8 @@ static int __bdi_set_max_ratio(struct ba
 		ret = -EINVAL;
 	} else {
 		bdi->max_ratio = max_ratio;
-		bdi->max_prop_frac = (FPROP_FRAC_BASE * max_ratio) / 100;
+		bdi->max_prop_frac = (FPROP_FRAC_BASE * max_ratio) /
+						(100 * BDI_RATIO_SCALE);
 	}
 	spin_unlock_bh(&bdi_lock);
 
_

Patches currently in -mm which might be from jefflexu@linux.alibaba.com are