nfs: Add DEALLOCATE support

This patch adds support for using the NFS v4.2 operation DEALLOCATE to
punch holes in a file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 2b28a21..022b761 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -491,6 +491,7 @@
 	/* nfs42 */
 	NFSPROC4_CLNT_SEEK,
 	NFSPROC4_CLNT_ALLOCATE,
+	NFSPROC4_CLNT_DEALLOCATE,
 };
 
 /* nfs41 types */
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index df6ed42..1e37fbb 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -232,5 +232,6 @@
 #define NFS_CAP_SECURITY_LABEL	(1U << 18)
 #define NFS_CAP_SEEK		(1U << 19)
 #define NFS_CAP_ALLOCATE	(1U << 20)
+#define NFS_CAP_DEALLOCATE	(1U << 21)
 
 #endif