[PATCH 1/2] f2fs: fix wrong calculation of block age

[qixiaoyu1]

Currently we wrongly calculate the new block age to
old * LAST_AGE_WEIGHT / 100.

Fix it to new * (100 - LAST_AGE_WEIGHT) / 100
                + old * LAST_AGE_WEIGHT / 100.

Signed-off-by: qixiaoyu1 <qixiaoyu1@xxxxxxxxxx>
---
 fs/f2fs/extent_cache.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 342af24b2f8c..93a1ab186517 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -874,11 +874,7 @@ void f2fs_update_read_extent_tree_range_compressed(struct inode *inode,
 static unsigned long long __calculate_block_age(unsigned long long new,
 						unsigned long long old)
 {
-	unsigned long long diff;
-
-	diff = (new >= old) ? new - (new - old) : new + (old - new);
-
-	return div_u64(diff * LAST_AGE_WEIGHT, 100);
+	return new - new / 100 * LAST_AGE_WEIGHT + old / 100 * LAST_AGE_WEIGHT;
 }
 
 /* This returns a new age and allocated blocks in ei */
-- 
2.36.1