On Thu, 2017-10-19 at 12:04 +0200, Arnd Bergmann wrote: > do_gettimeofday() is deprecated and we should generally use time64_t > based functions instead. > > In case of nfsd, all three users of nfssvc_boot only use the initial > time as a unique token, and are not affected by it overflowing, so they > are not affected by the y2038 overflow. > > This converts the structure to timespec64 anyway and adds comments > to all uses, to document that we have thought about it and avoid > having to look at it again. > > Signed-off-by: Arnd Bergmann <[email protected]> > --- > fs/nfsd/netns.h | 2 +- > fs/nfsd/nfs3xdr.c | 10 ++++++---- > fs/nfsd/nfs4proc.c | 5 +++-- > fs/nfsd/nfssvc.c | 2 +- > 4 files changed, 11 insertions(+), 8 deletions(-) > > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h > index 3714231a9d0f..1c91391f4805 100644 > --- a/fs/nfsd/netns.h > +++ b/fs/nfsd/netns.h > @@ -107,7 +107,7 @@ struct nfsd_net { > bool lockd_up; > > /* Time of server startup */ > - struct timeval nfssvc_boot; > + struct timespec64 nfssvc_boot; > > /* > * Max number of connections this nfsd container will allow. Defaults > diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c > index bf444b664011..3579e0ae1131 100644 > --- a/fs/nfsd/nfs3xdr.c > +++ b/fs/nfsd/nfs3xdr.c > @@ -747,8 +747,9 @@ nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p) > if (resp->status == 0) { > *p++ = htonl(resp->count); > *p++ = htonl(resp->committed); > - *p++ = htonl(nn->nfssvc_boot.tv_sec); > - *p++ = htonl(nn->nfssvc_boot.tv_usec); > + /* unique identifier, y2038 overflow can be ignored */ > + *p++ = htonl((u32)nn->nfssvc_boot.tv_sec); > + *p++ = htonl(nn->nfssvc_boot.tv_nsec); > } > return xdr_ressize_check(rqstp, p); > } > @@ -1118,8 +1119,9 @@ nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 > *p) > p = encode_wcc_data(rqstp, p, &resp->fh); > /* Write verifier */ > if (resp->status == 0) { > - *p++ = htonl(nn->nfssvc_boot.tv_sec); > - *p++ = htonl(nn->nfssvc_boot.tv_usec); > + /* unique identifier, y2038 overflow can be ignored */ > + *p++ = htonl((u32)nn->nfssvc_boot.tv_sec); > + *p++ = htonl(nn->nfssvc_boot.tv_nsec); > } > return xdr_ressize_check(rqstp, p); > } > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > index 7896f841482e..008ea0b627d0 100644 > --- a/fs/nfsd/nfs4proc.c > +++ b/fs/nfsd/nfs4proc.c > @@ -564,10 +564,11 @@ static void gen_boot_verifier(nfs4_verifier *verifier, > struct net *net) > > /* > * This is opaque to client, so no need to byte-swap. Use > - * __force to keep sparse happy > + * __force to keep sparse happy. y2038 time_t overflow is > + * irrelevant in this usage. > */ > verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec; > - verf[1] = (__force __be32)nn->nfssvc_boot.tv_usec; > + verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec; > memcpy(verifier->data, verf, sizeof(verifier->data)); > } > > diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c > index 6bbc717f40f2..28ff3e078af6 100644 > --- a/fs/nfsd/nfssvc.c > +++ b/fs/nfsd/nfssvc.c > @@ -516,7 +516,7 @@ int nfsd_create_serv(struct net *net) > register_inet6addr_notifier(&nfsd_inet6addr_notifier); > #endif > } > - do_gettimeofday(&nn->nfssvc_boot); /* record boot time */ > + ktime_get_real_ts64(&nn->nfssvc_boot); /* record boot time */ > return 0; > } >
I wonder if we'd be better off just using nfssvc_boot.tv_sec as the verifier? I don't see us ever calling that ktime_get_real_ts64 more than once per second for this purpose, and that would eliminate wraparound. That said, wraparound is not a huge concern here anyway, so this is certainly fine for now: Reviewed-by: Jeff Layton <[email protected]> _______________________________________________ Y2038 mailing list [email protected] https://lists.linaro.org/mailman/listinfo/y2038
