• Chuck Lever's avatar
    NFS: Fix security flavor negotiation with legacy binary mounts · eb54d437
    Chuck Lever authored
    Darrick J. Wong <darrick.wong@oracle.com> reports:
    > I have a kvm-based testing setup that netboots VMs over NFS, the
    > client end of which seems to have broken somehow in 3.10-rc1.  The
    > server's exports file looks like this:
    >
    > /storage/mtr/x64	192.168.122.0/24(ro,sync,no_root_squash,no_subtree_check)
    >
    > On the client end (inside the VM), the initrd runs the following
    > command to try to mount the rootfs over NFS:
    >
    > # mount -o nolock -o ro -o retrans=10 192.168.122.1:/storage/mtr/x64/ /root
    >
    > (Note: This is the busybox mount command.)
    >
    > The mount fails with -EINVAL.
    
    Commit 4580a92d "NFS: Use server-recommended security flavor by
    default (NFSv3)" introduced a behavior regression for NFS mounts
    done via a legacy binary mount(2) call.
    
    Ensure that a default security flavor is specified for legacy binary
    mount requests, since they do not invoke nfs_select_flavor() in the
    kernel.
    
    Busybox uses klibc's nfsmount command, which performs NFS mounts
    using the legacy binary mount data format.  /sbin/mount.nfs is not
    affected by this regression.
    Reported-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
    Tested-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Acked-by: default avatarWeston Andros Adamson <dros@netapp.com>
    Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
    eb54d437
super.c 70.2 KB