From 5180138604323895b5c291eca6aa7c20be494ade Mon Sep 17 00:00:00 2001 From: Konstantin Komarov Date: Mon, 1 Sep 2025 11:48:48 +0300 Subject: [PATCH] fs/ntfs3: Support timestamps prior to epoch Before it used an unsigned 64-bit type, which prevented proper handling of timestamps earlier than 1970-01-01. Switch to a signed 64-bit type to support pre-epoch timestamps. The issue was caught by xfstests. Signed-off-by: Konstantin Komarov --- fs/ntfs3/ntfs_fs.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h index 630128716ea7..2649fbe16669 100644 --- a/fs/ntfs3/ntfs_fs.h +++ b/fs/ntfs3/ntfs_fs.h @@ -979,11 +979,12 @@ static inline __le64 kernel2nt(const struct timespec64 *ts) */ static inline void nt2kernel(const __le64 tm, struct timespec64 *ts) { - u64 t = le64_to_cpu(tm) - _100ns2seconds * SecondsToStartOf1970; + s32 t32; + /* use signed 64 bit to support timestamps prior to epoch. xfstest 258. */ + s64 t = le64_to_cpu(tm) - _100ns2seconds * SecondsToStartOf1970; - // WARNING: do_div changes its first argument(!) - ts->tv_nsec = do_div(t, _100ns2seconds) * 100; - ts->tv_sec = t; + ts->tv_sec = div_s64_rem(t, _100ns2seconds, &t32); + ts->tv_nsec = t32 * 100; } static inline struct ntfs_sb_info *ntfs_sb(struct super_block *sb)