Messages in this thread | | | From | "NeilBrown" <> | Subject | Re: [PATCH] sunrpc: Fix incorrect parsing of expiry time | Date | Wed, 08 Mar 2023 09:30:59 +1100 |
| |
On Wed, 08 Mar 2023, Jerry Zhang wrote: > The expiry time field is mean to be expressed in seconds since boot.
Correct.
> The get_expiry() function parses a relative time value in seconds.
Incorrect. It parses and absoulte wall-clock time.
NeilBrown
> In order to get the absolute time of seconds since boot that the given > message will expire, the right thing is to add seconds_since_boot() > to the given relative value. > > Previously this logic was subtracting boot.tv_sec from the relative > value, which was causing some confusing behavior. The return type of > time64_t could possibly underflow if time since boot is greater than > the passed in relative argument. Also several checks in nfs code compare > the return value to 0 to indicate failure, and this could spuriously > be tripped if seconds since boot happened to match the argument. > > Fixes: c5b29f885afe ("sunrpc: use seconds since boot in expiry cache") > Signed-off-by: Jerry Zhang <Jerry@skydio.com> > --- > include/linux/sunrpc/cache.h | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h > index ec5a555df96f..b96b1319c93d 100644 > --- a/include/linux/sunrpc/cache.h > +++ b/include/linux/sunrpc/cache.h > @@ -301,16 +301,14 @@ static inline int get_time(char **bpp, time64_t *time) > } > > static inline time64_t get_expiry(char **bpp) > { > time64_t rv; > - struct timespec64 boot; > > if (get_time(bpp, &rv)) > return 0; > if (rv < 0) > return 0; > - getboottime64(&boot); > - return rv - boot.tv_sec; > + return rv + seconds_since_boot(); > } > > #endif /* _LINUX_SUNRPC_CACHE_H_ */ > -- > 2.37.3 > >
| |