Commit cd2d9922 authored Aug 12, 2019 by Theodore Ts'o

ext4: drop legacy pre-1970 encoding workaround

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 a4dad1ae ("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@mit.edu>

parent bb5835ed

fs/ext4/ext4.h

+1 −14

Original line number	Diff line number	Diff line
		@@ -828,21 +828,8 @@ 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;
		}

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