doc: use "file system" instead of "filesystem"

doc/api/addons.md

@@ -27,7 +27,7 @@ involving knowledge of several components and APIs:
   threads and all of the asynchronous behaviors of the platform. It also
   serves as a cross-platform abstraction library, giving easy, POSIX-like
   access across all major operating systems to many common system tasks, such
-  as interacting with the filesystem, sockets, timers, and system events. libuv
+  as interacting with the file system, sockets, timers, and system events. libuv
   also provides a threading abstraction similar to POSIX threads for
   more sophisticated asynchronous addons that need to move beyond the
   standard event loop. Addon authors should

doc/api/fs.md

@@ -1145,7 +1145,7 @@ changes:
 * `prefix` {string}
 * `options` {string|Object}
   * `encoding` {string} **Default:** `'utf8'`
-* Returns: {Promise}  Fulfills with a string containing the filesystem path
+* Returns: {Promise}  Fulfills with a string containing the file system path
   of the newly created temporary directory.
 
 Creates a unique temporary directory. A unique directory name is generated by
@@ -4400,7 +4400,7 @@ renamed. An `EPERM` error is reported when the watched directory is deleted.
 <!--type=misc-->
 
 This feature depends on the underlying operating system providing a way
-to be notified of filesystem changes.
+to be notified of file system changes.
 
 * On Linux systems, this uses [`inotify(7)`][].
 * On BSD systems, this uses [`kqueue(2)`][].
@@ -6934,7 +6934,7 @@ The times in the stat object have the following semantics:
   link(2), mknod(2), rename(2), unlink(2), utimes(2),
   read(2), and write(2) system calls.
 * `birthtime` "Birth Time": Time of file creation. Set once when the
-  file is created. On filesystems where birthtime is not available,
+  file is created. On file systems where birthtime is not available,
   this field may instead hold either the `ctime` or
   `1970-01-01T00:00Z` (ie, Unix epoch timestamp `0`). This value may be greater
   than `atime` or `mtime` in this case. On Darwin and other FreeBSD variants,

doc/api/modules.md

@@ -191,7 +191,7 @@ require(X) from module at path Y
    a. return the core module
    b. STOP
 2. If X begins with '/'
-   a. set Y to be the filesystem root
+   a. set Y to be the file system root
 3. If X begins with './' or '/' or '../'
    a. LOAD_AS_FILE(Y + X)
    b. LOAD_AS_DIRECTORY(Y + X)

doc/api/net.md

@@ -29,15 +29,15 @@ sockets on other operating systems.
 [`socket.connect()`][] take a `path` parameter to identify IPC endpoints.
 
 On Unix, the local domain is also known as the Unix domain. The path is a
-filesystem pathname. It gets truncated to an OS-dependent length of
+file system pathname. It gets truncated to an OS-dependent length of
 `sizeof(sockaddr_un.sun_path) - 1`. Typical values are 107 bytes on Linux and
 103 bytes on macOS. If a Node.js API abstraction creates the Unix domain socket,
 it will unlink the Unix domain socket as well. For example,
 [`net.createServer()`][] may create a Unix domain socket and
 [`server.close()`][] will unlink it. But if a user creates the Unix domain
 socket outside of these abstractions, the user will need to remove it. The same
 applies when a Node.js API creates a Unix domain socket but the program then
-crashes. In short, a Unix domain socket will be visible in the filesystem and
+crashes. In short, a Unix domain socket will be visible in the file system and
 will persist until unlinked.
 
 On Windows, the local domain is implemented using a named pipe. The path _must_

doc/api/report.md

@@ -567,9 +567,9 @@ In cases where standard streams are used, the value in `directory` is ignored.
 URLs are not supported. Defaults to a composite filename that contains
 timestamp, PID, and sequence number.
 
-`directory` specifies the filesystem directory where the report will be written.
-URLs are not supported. Defaults to the current working directory of the
-Node.js process.
+`directory` specifies the file system directory where the report will be
+written. URLs are not supported. Defaults to the current working directory of
+the Node.js process.
 
 ```js
 // Trigger report only on uncaught exceptions.