So, I'll ask the stupid question here if there is anyway to avoid this
from the server, just as disabling this?

On 10/24/06, Spencer Shepler <spencer.shepler at sun.com> wrote:
>
> Joe,
>
> With the "chmod g+s" done first, "mandatory file locking" has been
> enabled because the execute bit has not been set.  The NFS server
> doesn't like files that are enabled for mandatory file locking
> because it can be blocked when it goes to read/write from that file (**).
>
> The failure of "cat" occurs when the client is checking access
> with the ACCESS NFS call and the server sees that mandatory file
> locking is possible on the file (setgid without execute) and will
> deny read/write accesa; therefore, cat fails.
>
> This will occur regardless of client; interesting to note that the
> Solaris chmod command will not allow a "chmod g+s" if the execute
> bit is not set.  It will provide a warning and set the permission
> but without setgid.  The user must ask for the mandatory file locking
> with the +l flag.
>
> Spencer
>
> ** The NFS server and underlying filesystems actually have a way to
> avoid blocking the server on mandatory locked files but there is
> a possibility that a filesystem may not abide by all the rules and
> therefore we have a paranoid NFS server.
>
>
> On Tue, Joe Little wrote:
> > Snoop attached, Its ZFS backend
> >
> > Test was to create a file "touch file" over NFS from an ubuntu 6.10
> > client of a B47 OpenSolaris server. That succeeded. I then ran "chmod
> > g+s" without first running "chmod g+x". That succeeds. Finally, I run
> > "cat file" and the resulting snoop is what happens, with a "cat: file:
> > Permissions denied" on the client.
> >
> >
> >
> > On 10/23/06, Spencer Shepler <spencer.shepler at sun.com> wrote:
> > >On Mon, Joe Little wrote:
> > >> I have B47 bits on one of my servers, nad we recently discovered
> > >> something odd. Users from linux clients, if they have add a +s to a
> > >> file's group permissions w/o an +x there first, would actually lose
> > >> read access to the file itself (permission denied). It would seem that
> > >> the file handles are no longer correct for a rwxr-Sr-x type file
> > >> (incorrect assignment and all).
> > >>
> > >> It took a bit to figure out that added the execute bit returned the
> > >> file to the owner, but why should altering group permissions ever
> > >> effect the owner?
> > >>
> > >> Again, this is only with a Solaris NFS server and so far has been seen
> > >> on linux NFS clients. It definitely smells/tastes like an error.
> > >
> > >Hi, Joe.
> > >
> > >Info about the underlying filesystem at the Solaris server and a
> > >binary snoop trace of the failing interaction would be the next
> > >steps to determining the root of the problem.
> > >
> > >Spencer
> > >
>
>
>

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