On Tue, Jun 27, 2017 at 04:03:26PM +0200, Christoph Hellwig wrote:
> ping?
>
> On Wed, Jun 14, 2017 at 01:22:38PM +0200, Christoph Hellwig wrote:
> > Changing behavior based on the version code is a timebomb waiting to
> > happen, and not easily bisectable. Drop it and leave any removal
> > to explicit developer action. (And I don't think file system
> > should _ever_ remove backwards compatibility that has no explicit
> > flag, but I'll leave that to the ext4 folks).
> >
> > Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> > ---
> > fs/ext4/ext4.h | 12 +++---------
> > 1 file changed, 3 insertions(+), 9 deletions(-)
> >
> > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> > index 32191548abed..d35749e7cf9f 100644
> > --- a/fs/ext4/ext4.h
> > +++ b/fs/ext4/ext4.h
> > @@ -838,21 +838,15 @@ static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
> > {
> > if (unlikely(sizeof(time->tv_sec) > 4 &&
> > (extra & cpu_to_le32(EXT4_EPOCH_MASK)))) {
> > -#if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
> > +
> > /* Handle legacy encoding of pre-1970 dates with epoch
> > - * bits 1,1. We assume that by kernel version 4.20,
> > - * everyone will have run fsck over the affected
> > - * filesystems to correct the problem. (This
> > - * backwards compatibility may be removed before this
> > - * time, at the discretion of the ext4 developers.)
> > + * 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
> > - 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;
> > }
Looks good --- I agree that timebombs are a very bad idea.
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
- Eric
