diff --git a/block/vvfat.c b/block/vvfat.c
index 063f731..7b6a405 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -868,7 +868,8 @@ static int init_directories(BDRVVVFATState* s,
     {
 	direntry_t* entry=array_get_next(&(s->directory));
 	entry->attributes=0x28; /* archive | volume label */
-	snprintf((char*)entry->name,11,"QEMU VVFAT");
+	snprintf((char*)entry->name,8,"QEMU VV");
+	snprintf((char*)entry->extension,3,"FAT");
     }
 
     /* Now build FAT, and write back information into directory */
@@ -2256,7 +2257,7 @@ static int commit_one_file(BDRVVVFATState* s,
 	c = c1;
     }
 
-    ftruncate(fd, size);
+    assert(!ftruncate(fd, size));
     close(fd);
 
     return commit_mappings(s, first_cluster, dir_index);