CIFS: Make cifsFileInfo_put work with strict cache mode

On strict cache mode when we close the last file handle of the inode we
should set invalid_mapping flag on this inode to prevent data coherency
problem when we open it again but it has been modified on the server.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 7852cd6..ac51cd2 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -40,6 +40,7 @@
 #define CIFS_MOUNT_FSCACHE	0x8000 /* local caching enabled */
 #define CIFS_MOUNT_MF_SYMLINKS	0x10000 /* Minshall+French Symlinks enabled */
 #define CIFS_MOUNT_MULTIUSER	0x20000 /* multiuser mount */
+#define CIFS_MOUNT_STRICT_IO	0x40000 /* strict cache mode */
 
 struct cifs_sb_info {
 	struct rb_root tlink_tree;