On Sat, Sep 05, 2020 at 11:02:31PM +0100, Matthew Wilcox wrote:
> On Sat, Sep 05, 2020 at 09:47:03AM -0700, Darrick J. Wong wrote:
> > +static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
> > + __s32 *timer_lo, __s8 *timer_hi, s64 timer)
> > +{
> > + *timer_lo = timer;
> > + if (d->d_fieldmask & FS_DQ_BIGTIME)
> > + *timer_hi = timer >> 32;
> > + else
> > + *timer_hi = 0;
> > +}
>
> Is that actually the right thing to do? If FS_DQ_BIGTIME is not set,
> I would expect us to avoid writing to timer_hi at all. Alternatively, if
> we do want to write to timer_hi, why not write to it unconditionally?
If the flag isn't set, then the space used by timer_hi is a zero-filled
padding field. Therefore, I made this function zero timer_hi if the
bigtime flag isn't set. It's redundant with the memset five lines up
from the call site, but I don't like leaving logic bombs in case this
function ever gets exported elsewhere.
--D
