* Eric Blake (ebl...@redhat.com) wrote: > On 7/29/19 7:27 PM, piaojun wrote: > > Use F_GETLK for fcntl when F_OFD_GETLK not defined. > > Which system are you hitting this problem on? > > The problem with F_GETLK is that it is NOT as safe as F_OFD_GETLK. > > We already have fcntl_op_getlk and qemu_probe_lock_ops() in util/osdep.c > to not only determine which form to use, but also to emit a warning to > the end user if we had to fall back to the unsafe F_GETLK. Why is your > code not reusing that logic? > > > > > Signed-off-by: Jun Piao <piao...@huawei.com> > > --- > > contrib/virtiofsd/passthrough_ll.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/contrib/virtiofsd/passthrough_ll.c > > b/contrib/virtiofsd/passthrough_ll.c > > index 9ae1381..757785b 100644 > > --- a/contrib/virtiofsd/passthrough_ll.c > > +++ b/contrib/virtiofsd/passthrough_ll.c > > @@ -1619,7 +1619,11 @@ static void lo_getlk(fuse_req_t req, fuse_ino_t ino, > > return; > > } > > > > +#ifdef F_OFD_GETLK > > ret = fcntl(plock->fd, F_OFD_GETLK, lock); > > +#else > > + ret = fcntl(plock->fd, F_GETLK, lock); > > +#endif > > Hmm. Since this is in contrib, you are trying to compile something that > is independent of util/osdep.c (at least, I assume that's the case, as > contrib/virtiofsd/ is not even part of qemu.git master yet - in which > case, why is this not being squashed in to the patch introducing that > file, rather than sent standalone). On the other hand, that raises the > question - who is trying to use virtiofsd on a kernel that is too old to > provid F_OFD_GETLK? Isn't the whole point of virtiofsd to be speeding > up modern usage, at which point an old kernel is just gumming up the > works? It seems like you are better off letting compilation fail on a > system that is too old to support decent F_OFD_GETLK, rather than > silently falling back to something that is unsafe.
It is, but I guess the answer here is someone wanted to build on RHEL7. Dave > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3226 > Virtualization: qemu.org | libvirt.org > > _______________________________________________ > Virtio-fs mailing list > virtio...@redhat.com > https://www.redhat.com/mailman/listinfo/virtio-fs -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
