JS file system: distinguish between atime, mtime, and ctime

ChangeLog.md

@@ -25,6 +25,8 @@ See docs/process.md for more on how version tagging works.
 -----------------
 - libunwind was updated to LLVM 19.1.4. (#22394)
 - mimalloc was updated to 2.1.7. (#21548)
+- The file system was updated to independently track atime, mtime and ctime
+  instead of using the same time for all three. (#22998)
 
 3.1.72 - 11/19/24
 -----------------

src/library_fs.js

@@ -146,6 +146,7 @@ FS.staticInit();
         this.name = name;
         this.mode = mode;
         this.rdev = rdev;
+        this.atime = this.mtime = this.ctime = Date.now();
       }
       get read() {
         return (this.mode & this.readMode) === this.readMode;
@@ -943,7 +944,7 @@ FS.staticInit();
       }
       node.node_ops.setattr(node, {
         mode: (mode & {{{ cDefs.S_IALLUGO }}}) | (node.mode & ~{{{ cDefs.S_IALLUGO }}}),
-        timestamp: Date.now()
+        ctime: Date.now()
       });
     },
     lchmod(path, mode) {
@@ -1016,7 +1017,8 @@ FS.staticInit();
       var lookup = FS.lookupPath(path, { follow: true });
       var node = lookup.node;
       node.node_ops.setattr(node, {
-        timestamp: Math.max(atime, mtime)
+        atime: atime,
+        mtime: mtime
       });
     },
     open(path, flags, mode = 0o666) {
@@ -1618,7 +1620,7 @@ FS.staticInit();
             buffer[offset+i] = result;
           }
           if (bytesRead) {
-            stream.node.timestamp = Date.now();
+            stream.node.atime = Date.now();
           }
           return bytesRead;
         },
@@ -1631,7 +1633,7 @@ FS.staticInit();
             }
           }
           if (length) {
-            stream.node.timestamp = Date.now();
+            stream.node.mtime = stream.node.ctime = Date.now();
           }
           return i;
         }

src/library_lz4.js

@@ -70,7 +70,7 @@ addToLibrary({
       node.mode = mode;
       node.node_ops = LZ4.node_ops;
       node.stream_ops = LZ4.stream_ops;
-      node.timestamp = (mtime || new Date).getTime();
+      this.atime = this.mtime = this.ctime = (mtime || new Date).getTime();
       assert(LZ4.FILE_MODE !== LZ4.DIR_MODE);
       if (mode === LZ4.FILE_MODE) {
         node.size = contents.end - contents.start;
@@ -95,19 +95,18 @@ addToLibrary({
           gid: 0,
           rdev: 0,
           size: node.size,
-          atime: new Date(node.timestamp),
-          mtime: new Date(node.timestamp),
-          ctime: new Date(node.timestamp),
+          atime: new Date(node.atime),
+          mtime: new Date(node.mtime),
+          ctime: new Date(node.ctime),
           blksize: 4096,
           blocks: Math.ceil(node.size / 4096),
         };
       },
       setattr(node, attr) {
-        if (attr.mode !== undefined) {
-          node.mode = attr.mode;
-        }
-        if (attr.timestamp !== undefined) {
-          node.timestamp = attr.timestamp;
+        for (const key of ['mode', 'atime', 'mtime', 'ctime']) {
+          if (attr[key]) {
+            node[key] = attr[key];
+          }
         }
       },
       lookup(parent, name) {

src/library_memfs.js

@@ -92,11 +92,11 @@ addToLibrary({
         node.node_ops = MEMFS.ops_table.chrdev.node;
         node.stream_ops = MEMFS.ops_table.chrdev.stream;
       }
-      node.timestamp = Date.now();
+      node.atime = node.mtime = node.ctime = Date.now();
       // add the new node to the parent
       if (parent) {
         parent.contents[name] = node;
-        parent.timestamp = node.timestamp;
+        parent.atime = parent.mtime = parent.ctime = node.atime;
       }
       return node;
     },
@@ -161,21 +161,20 @@ addToLibrary({
         } else {
           attr.size = 0;
         }
-        attr.atime = new Date(node.timestamp);
-        attr.mtime = new Date(node.timestamp);
-        attr.ctime = new Date(node.timestamp);
+        attr.atime = new Date(node.atime);
+        attr.mtime = new Date(node.mtime);
+        attr.ctime = new Date(node.ctime);
         // NOTE: In our implementation, st_blocks = Math.ceil(st_size/st_blksize),
         //       but this is not required by the standard.
         attr.blksize = 4096;
         attr.blocks = Math.ceil(attr.size / attr.blksize);
         return attr;
       },
       setattr(node, attr) {
-        if (attr.mode !== undefined) {
-          node.mode = attr.mode;
-        }
-        if (attr.timestamp !== undefined) {
-          node.timestamp = attr.timestamp;
+        for (const key of ["mode", "atime", "mtime", "ctime"]) {
+          if (attr[key]) {
+            node[key] = attr[key];
+          }
         }
         if (attr.size !== undefined) {
           MEMFS.resizeFileStorage(node, attr.size);
@@ -207,22 +206,21 @@ addToLibrary({
         }
         // do the internal rewiring
         delete old_node.parent.contents[old_node.name];
-        old_node.parent.timestamp = Date.now()
-        old_node.name = new_name;
         new_dir.contents[new_name] = old_node;
-        new_dir.timestamp = old_node.parent.timestamp;
+        old_node.name = new_name;
+        new_dir.ctime = new_dir.mtime = old_node.parent.ctime = old_node.parent.mtime = Date.now();
       },
       unlink(parent, name) {
         delete parent.contents[name];
-        parent.timestamp = Date.now();
+        parent.ctime = parent.mtime = Date.now();
       },
       rmdir(parent, name) {
         var node = FS.lookupNode(parent, name);
         for (var i in node.contents) {
           throw new FS.ErrnoError({{{ cDefs.ENOTEMPTY }}});
         }
         delete parent.contents[name];
-        parent.timestamp = Date.now();
+        parent.ctime = parent.mtime = Date.now();
       },
       readdir(node) {
         var entries = ['.', '..'];
@@ -282,7 +280,7 @@ addToLibrary({
 
         if (!length) return 0;
         var node = stream.node;
-        node.timestamp = Date.now();
+        node.mtime = node.ctime = Date.now();
 
         if (buffer.subarray && (!node.contents || node.contents.subarray)) { // This write is from a typed array to a typed array?
           if (canOwn) {

src/library_nodefs.js

@@ -166,9 +166,10 @@ addToLibrary({
             // update the common node structure mode as well
             node.mode = attr.mode;
           }
-          if (attr.timestamp !== undefined) {
-            var date = new Date(attr.timestamp);
-            fs.utimesSync(path, date, date);
+          if (attr.atime || attr.mtime) {
+            var atime = attr.atime && new Date(attr.atime);
+            var mtime = attr.mtime && new Date(attr.mtime);
+            fs.utimesSync(path, atime, mtime);
           }
           if (attr.size !== undefined) {
             fs.truncateSync(path, attr.size);

src/library_noderawfs.js

@@ -112,13 +112,13 @@ addToLibrary({
       fs.ftruncateSync(stream.nfd, len);
     },
     utime(path, atime, mtime) {
-      // -1 here for atime or mtime means UTIME_OMIT was passed.  Since node
+      // null here for atime or mtime means UTIME_OMIT was passed.  Since node
       // doesn't support this concept we need to first find the existing
       // timestamps in order to preserve them.
-      if (atime == -1 || mtime == -1) {
+      if ((atime === null) || (mtime === null)) {
         var st = fs.statSync(path);
-        if (atime == -1) atime = st.atimeMs;
-        if (mtime == -1) mtime = st.mtimeMs;
+        atime ||= st.atimeMs;
+        mtime ||= st.mtimeMs;
       }
       fs.utimesSync(path, atime/1000, mtime/1000);
     },

src/library_proxyfs.js

@@ -63,9 +63,10 @@ addToLibrary({
             // update the common node structure mode as well
             node.mode = attr.mode;
           }
-          if (attr.timestamp !== undefined) {
-            var date = new Date(attr.timestamp);
-            node.mount.opts.fs.utime(path, date, date);
+          if (attr.atime || attr.mtime) {
+            var atime = new Date(attr.atime || attr.mtime);
+            var mtime = new Date(attr.mtime || attr.atime);
+            node.mount.opts.fs.utime(path, atime, mtime);
           }
           if (attr.size !== undefined) {
             node.mount.opts.fs.truncate(path, attr.size);

src/library_syscall.js

@@ -968,7 +968,7 @@ var SyscallsLibrary = {
       if (nanoseconds == {{{ cDefs.UTIME_NOW }}}) {
         atime = now;
       } else if (nanoseconds == {{{ cDefs.UTIME_OMIT }}}) {
-        atime = -1;
+        atime = null;
       } else {
         atime = (seconds*1000) + (nanoseconds/(1000*1000));
       }
@@ -978,15 +978,14 @@ var SyscallsLibrary = {
       if (nanoseconds == {{{ cDefs.UTIME_NOW }}}) {
         mtime = now;
       } else if (nanoseconds == {{{ cDefs.UTIME_OMIT }}}) {
-        mtime = -1;
+        mtime = null;
       } else {
         mtime = (seconds*1000) + (nanoseconds/(1000*1000));
       }
     }
-    // -1 here means UTIME_OMIT was passed.  FS.utime tables the max of these
-    // two values and sets the timestamp to that single value.  If both were
-    // set to UTIME_OMIT then we can skip the call completely.
-    if (mtime != -1 || atime != -1) {
+    // null here means UTIME_OMIT was passed. If both were set to UTIME_OMIT then
+    // we can skip the call completely.
+    if ((mtime ?? atime) !== null) {
       FS.utime(path, atime, mtime);
     }
     return 0;

src/library_tty.js

@@ -79,7 +79,7 @@ addToLibrary({
           buffer[offset+i] = result;
         }
         if (bytesRead) {
-          stream.node.timestamp = Date.now();
+          stream.node.atime = Date.now();
         }
         return bytesRead;
       },
@@ -95,7 +95,7 @@ addToLibrary({
           throw new FS.ErrnoError({{{ cDefs.EIO }}});
         }
         if (length) {
-          stream.node.timestamp = Date.now();
+          stream.node.mtime = stream.node.ctime = Date.now();
         }
         return i;
       }

src/library_workerfs.js

@@ -57,7 +57,7 @@ addToLibrary({
       node.mode = mode;
       node.node_ops = WORKERFS.node_ops;
       node.stream_ops = WORKERFS.stream_ops;
-      node.timestamp = (mtime || new Date).getTime();
+      node.atime = node.mtime = node.ctime = (mtime || new Date).getTime();
       assert(WORKERFS.FILE_MODE !== WORKERFS.DIR_MODE);
       if (mode === WORKERFS.FILE_MODE) {
         node.size = contents.size;
@@ -82,19 +82,18 @@ addToLibrary({
           gid: 0,
           rdev: 0,
           size: node.size,
-          atime: new Date(node.timestamp),
-          mtime: new Date(node.timestamp),
-          ctime: new Date(node.timestamp),
+          atime: new Date(node.atime),
+          mtime: new Date(node.mtime),
+          ctime: new Date(node.ctime),
           blksize: 4096,
           blocks: Math.ceil(node.size / 4096),
         };
       },
       setattr(node, attr) {
-        if (attr.mode !== undefined) {
-          node.mode = attr.mode;
-        }
-        if (attr.timestamp !== undefined) {
-          node.timestamp = attr.timestamp;
+        for (const key of ["mode", "atime", "mtime", "ctime"]) {
+          if (attr[key]) {
+            node[key] = attr[key];
+          }
         }
       },
       lookup(parent, name) {

test/fs/test_fs_js_api.c

@@ -439,17 +439,10 @@ void test_fs_utime() {
     assert(utimeStats.st_atime == 10);
     assert(utimeStats.st_atim.tv_sec == 10);
 
-    // WasmFS correctly sets both times, but the legacy API sets both times to the max of atime and mtime
-    // and does not correctly handle nanseconds.
-#if WASMFS
     assert(utimeStats.st_atim.tv_nsec == 500000000);
 
     assert(utimeStats.st_mtime == 8);
     assert(utimeStats.st_mtim.tv_sec == 8);
-#else
-    assert(utimeStats.st_mtime == 10);
-    assert(utimeStats.st_mtim.tv_sec == 10);
-#endif
 
     remove("utimetest");
 }

test/stat/test_chmod.c

@@ -45,6 +45,7 @@ void cleanup() {
 void test() {
   int err;
   int lastctime;
+  int lastmtime;
   struct stat s;
 
   //
@@ -54,6 +55,7 @@ void test() {
   memset(&s, 0, sizeof s);
   stat("file", &s);
   lastctime = s.st_ctime;
+  lastmtime = s.st_mtime;
   sleep(1);
 
   // do the actual chmod
@@ -64,11 +66,13 @@ void test() {
   stat("file", &s);
   assert(s.st_mode == (S_IWUSR | S_IFREG));
   assert(s.st_ctime != lastctime);
+  assert(s.st_mtime == lastmtime);
 
   //
   // fchmod a file
   //
   lastctime = s.st_ctime;
+  lastmtime = s.st_mtime;
   sleep(1);
 
   err = fchmod(open("file", O_WRONLY), S_IXUSR);
@@ -78,11 +82,13 @@ void test() {
   stat("file", &s);
   assert(s.st_mode == (S_IXUSR | S_IFREG));
   assert(s.st_ctime != lastctime);
+  assert(s.st_mtime == lastmtime);
 
   //
   // fchmodat a file
   //
   lastctime = s.st_ctime;
+  lastmtime = s.st_mtime;
   sleep(1);
   err = fchmodat(AT_FDCWD, "otherfile", S_IXUSR, 0);
   assert(!err);
@@ -91,6 +97,7 @@ void test() {
   stat("otherfile", &s);
   assert(s.st_mode == (S_IXUSR | S_IFREG));
   assert(s.st_ctime != lastctime);
+  assert(s.st_mtime == lastmtime);
 
   //
   // chmod a folder
@@ -99,6 +106,7 @@ void test() {
   memset(&s, 0, sizeof s);
   stat("folder", &s);
   lastctime = s.st_ctime;
+  lastmtime = s.st_mtime;
   sleep(1);
 
   // do the actual chmod
@@ -108,6 +116,7 @@ void test() {
   stat("folder", &s);
   assert(s.st_mode == (S_IWUSR | S_IXUSR | S_IFDIR));
   assert(s.st_ctime != lastctime);
+  assert(s.st_mtime == lastmtime);
 
 #ifndef WASMFS // TODO https://github.com/emscripten-core/emscripten/issues/15948
   lstat("file-link", &s);

test/utime/test_futimens.c

@@ -105,12 +105,6 @@ void test() {
   err = futimens(fd, newtimes);
   assert(!err);
 
-#if defined(__EMSCRIPTEN__) && !defined(WASMFS) && !defined(NODERAWFS)
-  // The original emscripten FS (in JS) only supports a single timestamp so both
-  // mtime and atime will always be the same.
-  times[0].tv_sec = 42;
-  times[0].tv_nsec = 88;
-#endif
   times[1].tv_sec = 42;
   times[1].tv_nsec = 88;
   check_times(fd, times, 0);