f2fs: fix overflow when calculating utilization on 32-bit

Use div_u64 to fix overflow when calculating utilization. *long int* is 4-bytes on 32-bit so (user blocks * 100) might be overflow if disk size is over e.g. 512GB. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix overflow when calculating utilization on 32-bit
Use div_u64 to fix overflow when calculating utilization. *long int* is 4-bytes on 32-bit so (user blocks * 100) might be overflow if disk size is over e.g. 512GB. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Changman Lee · Jaegeuk Kim
1 parent 47b3bc9073
Showing 1 changed file with 1 additions and 2 deletions Side-by-side Diff
fs/f2fs/segment.h
@@ -464,8 +464,7 @@
  
 static inline int utilization(struct f2fs_sb_info *sbi)
 {
-	return (long int)valid_user_blocks(sbi) * 100 /
-			(long int)sbi->user_block_count;
+	return div_u64(valid_user_blocks(sbi) * 100, sbi->user_block_count);
 }
  
 /*
...	...	@@ -464,8 +464,7 @@
464	464
465	465	static inline int utilization(struct f2fs_sb_info *sbi)
466	466	{
467		- return (long int)valid_user_blocks(sbi) * 100 /
468		- (long int)sbi->user_block_count;
	467	+ return div_u64(valid_user_blocks(sbi) * 100, sbi->user_block_count);
469	468	}
470	469
471	470	/*