RE: recent nfs change causes autofs regression

Ian Kent
2007-08-31T05:09:33Z

On Fri, 31 Aug 2007, Trond Myklebust wrote:

> On Thu, 2007-08-30 at 16:44 -0700, Hua Zhong wrote:
> > > How is the NFS client to know that these directories are disjoint, or
> > > that no-one will ever create a hard link from one directory to another?
> > > To my knowledge, the only way to ensure this is to put them on
> > > different disk partitions.
> > >
> > > I don't know if all Unix systems have this issue, but I have been told
> > > that Solaris at least has it.
> >
> > Does Solaris enforces this "mount with same options" as default?
>
> No. Solaris defaults to breaking cache consistency.
>
> > > > "working" as in "I can mount the directory and do my work". And there
> > > > has never been any problems as far as I know.
> > >
> > > That is too narrow a definition: the minimum should be "everyone can
> > > mount their directories and do their work". Your particular setup may
> > > be safe, but that is why we have overrides: the default should be for the
> > > kernel to be conservative, and to _tell_ users what it thinks is wrong.
> >
> > Every engineer in our organization mounts it too. No problem until now.
>
> I believe I've already explained why that isn't a sufficient metric.
> What is your point?
>
> > It's not very conservative to suddenly change default behavior and break
> > autofs mounts. There is not even one kernel message that "_tells_ user why
> > it thinks it's wrong". It just silently fails.
>
> No it doesn't. It reports an error code to the caller. If autofs is
> failing silently, then that is a bug in autofs: mount will report the
> error to the user.

Actually, yes, it looks like I'm not logging mount errors at the correct
log level. Oops.

Ian