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>
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 3489015..d4b003d 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -207,6 +207,7 @@
 #define NFS_INO_INVALID_ACL	0x0010		/* cached acls are invalid */
 #define NFS_INO_REVAL_PAGECACHE	0x0020		/* must revalidate pagecache */
 #define NFS_INO_REVAL_FORCED	0x0040		/* force revalidation ignoring a delegation */
+#define NFS_INO_INVALID_LABEL	0x0080		/* cached label is invalid */
 
 /*
  * Bit offsets in flags field
@@ -352,6 +353,8 @@
 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
 extern int nfs_setattr(struct dentry *, struct iattr *);
 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr);
+extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
+				struct nfs4_label *label);
 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
 extern void put_nfs_open_context(struct nfs_open_context *ctx);
 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode);