diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index c517fc0..413eaaf 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -75,6 +75,7 @@
 	unsigned long root_cluster;   /* first cluster of the root directory */
 	unsigned long fsinfo_sector;  /* sector number of FAT32 fsinfo */
 	struct mutex fat_lock;
+	struct mutex nfs_build_inode_lock;
 	struct mutex s_lock;
 	unsigned int prev_free;      /* previously allocated cluster number */
 	unsigned int free_clusters;  /* -1 if undefined */