-@file{filesys} directory from multiple threads at once. For now, we
-recommend adding a single lock that controls access to the file system
-code. You should acquire this lock before calling any functions in
-the @file{filesys} directory, and release it afterward. Don't forget
-that @func{process_execute} also accesses files. @strong{For now, we
-recommend against modifying code in the @file{filesys} directory.}
+@file{filesys} directory from multiple threads at once. Your system
+call implementation must treat the file system code as a critical
+section. Don't forget
+that @func{process_execute} also accesses files. For now, we
+recommend against modifying code in the @file{filesys} directory.