On Tue, 12 Oct 2010 16:34:45 -0400 Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > On Oct 12, 2010, at 4:26 PM, Jeff Layton wrote: > > > On Tue, 12 Oct 2010 16:21:00 -0400 > > Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> wrote: > > > >> On Tue, 2010-10-12 at 15:52 -0400, Jeff Layton wrote: > >>> On Tue, 12 Oct 2010 15:44:09 -0400 > >>> Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> wrote: > >>> > >>>> On Tue, 2010-10-12 at 15:18 -0400, Jeff Layton wrote: > >>>> > >>>>> I think the part that causes problems is having userspace do this. In > >>>>> theory, if the kernel were in charge of sending the UMNT, then it's not > >>>>> really a problem since it knows when to do it. If we have code that > >>>>> sends a UMNT already, why not do a best-effort UMNT call from the > >>>>> kernel when we tear down the sb? > >>>> > >>>> Purely for the pleasure of allowing the server to maintain inaccurate > >>>> statistics about who is currently mounting what? I think not... > >>>> > >>>> You can get far more accurate results by replacing the MNT/UMNT state > >>>> counter with a purely server-based scheme to track who accessed one or > >>>> more files on each exported partition in the past 5 minutes or so. That > >>>> would even work with NFSv4... > >>>> > >>> > >>> True, but for better or worse, UMNT is part of the protocol. It seems > >>> like we ought to do our best to implement it, even if it is > >>> fundamentally flawed. > >>> > >> > >> UMNTALL is part of the same protocol, and yet we have never implemented > >> that. Just because something is documented, it doesn't mean we have to > >> do it... > >> > >> The bottom line is that UMNT doesn't do what it advertises itself as > >> doing, and so we should not waste space supporting it in the kernel. We > >> shouldn't do so in userspace either. > >> > > > > Fair enough. Like Chuck I don't have strong feelings about it, other > > than seeing no need to continue shipping umount.nfs. > > Careful... we still need umount.nfs, which is a link to mount.nfs. Something in user space has to kick off local namespace changes, even if the server isn't affected. > Most other filesystems don't need a umount helper. If there isn't one present then /bin/umount takes care of the umount() call and cleaning the entry out of /etc/mtab. My understanding was that umount.nfs only existed because it was needed to handle the UMNT RPC. Without that, there's really no need for it. ...or am I overlooking something? -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
