From: Theodore Ts'o <tytso(a)mit.edu>
mainline inclusion
from mainline-5.4-rc1
commit cd2d99229dc96219547e6349841e1aad851c6acc
category: bugfix
bugzilla: 50526
CVE: NA
---------------------------
Originally, support for expanded timestamps had a bug in that pre-1970
times were erroneously encoded as being in the the 24th century. This
was fixed in commit a4dad1ae24f8 ("ext4: Fix handling of extended
tv_sec") which landed in 4.4. Starting with 4.4, pre-1970 timestamps
were correctly encoded, but for backwards compatibility those
incorrectly encoded timestamps were mapped back to the pre-1970 dates.
Given that backwards compatibility workaround has been around for 4
years, and given that running e2fsck from e2fsprogs 1.43.2 and later
will offer to fix these timestamps (which has been released for 3
years), it's past time to drop the legacy workaround from the kernel.
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Signed-off-by: Yu Kuai <yukuai3(a)huawei.com>
Reviewed-by: zhangyi (F) <yi.zhang(a)huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
---
fs/ext4/ext4.h | 15 +--------------
1 file changed, 1 insertion(+), 14 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2a63c69bd19e2..816d6a83d14be 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -835,21 +835,8 @@ static inline __le32 ext4_encode_extra_time(struct timespec64 *time)
static inline void ext4_decode_extra_time(struct timespec64 *time,
__le32 extra)
{
- if (unlikely(extra & cpu_to_le32(EXT4_EPOCH_MASK))) {
-
-#if 1
- /* Handle legacy encoding of pre-1970 dates with epoch
- * bits 1,1. (This backwards compatibility may be removed
- * at the discretion of the ext4 developers.)
- */
- u64 extra_bits = le32_to_cpu(extra) & EXT4_EPOCH_MASK;
- if (extra_bits == 3 && ((time->tv_sec) & 0x80000000) != 0)
- extra_bits = 0;
- time->tv_sec += extra_bits << 32;
-#else
+ if (unlikely(extra & cpu_to_le32(EXT4_EPOCH_MASK)))
time->tv_sec += (u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK) << 32;
-#endif
- }
time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
}
--
2.25.1