NFS: Client implementation of Labeled-NFS

This patch implements the client transport and handling support for labeled
NFS. The patch adds two functions to encode and decode the security label
recommended attribute which makes use of the LSM hooks added earlier. It also
adds code to grab the label from the file attribute structures and encode the
label to be sent back to the server.

Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index b30c003b47d1..76e1ee5d03ed 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2417,8 +2417,21 @@ static int nfs_bdi_register(struct nfs_server *server)
 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
                         struct nfs_mount_info *mount_info)
 {
-        return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
-                                                                0, NULL);
+        int error;
+        unsigned long kflags = 0, kflags_out = 0;
+        if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
+                kflags |= SECURITY_LSM_NATIVE_LABELS;
+
+        error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
+                                                kflags, &kflags_out);
+        if (error)
+                goto err;
+
+        if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
+                !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
+                NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
+err:
+        return error;
 }
 EXPORT_SYMBOL_GPL(nfs_set_sb_security);